PaleoVeganology

Speciesism = Creationism; Treat It That Way

2012-01-21T23:42:00.000-08:00

You may have noticed a distinct lack of animal rights talk on this blog last year. That wasn’t an accident, although it’s not really accurate to say it was deliberate, either. The thing is, I have little patience for “philosophy,” particularly when it comes to explaining why I don’t eat animals. To me, the foundation of veganism is self-evident; I noted last year that there’s good evidence to think that empathy for animals is simply a given of human nature. As such, to my mind it requires no more philosophical justification than breathing or walking upright. I thus treat the contrary position that it is wrong – or, some say, unnatural – to feel or act on empathy for nonhumans as akin to claims about the divinity of Hebrew zombies, or the healing powers of trigonal silicate structures. That is to say, the burden of proof lies with the other side, not with mine.

But I’ve started noticing that a lot of other vegans don’t do this; we spend a lot of bandwidth and paper trying to convince the world that it’s OK to indulge such empathy; or worse, trying to convince the world that animal suffering really is similar enough to our own that animals deserve significantly more robust moral and ethical consideration than we currently give them. Entire books have been written on the subject. I’ve even read a few of them.

In short, we’ve been acting like the burden of proof lies with us. But it doesn’t, and we really ought to start acting like it doesn’t.

I came to my veganism and support for animal rights/liberation/libertarianism not primarily through works of animal advocacy, philosophy or ethics, but through my interest in and study of biology and evolution. Once I got a grasp on the concept of homology, the ethical implications followed naturally, and the ethical foundation seemed obvious to me: everything we know about brain evolution tells us – or ought to – that the capacity for suffering is conserved in all vertebrates. So are consciousness, pain, emotion and most of the other supposedly unique human mental faculties whose alleged lack in animals are often cited as justification for exploiting them ruthlessly.

Biologist Gerhard Roth is clear on the evidence for this point (emphasis added) :

All tetrapod vertebrates (amphibians, reptiles, birds, mammals) have brains that – despite enormous differences in outer appearance, overall size and relative size of major parts of the brain – are very similar in general organization and even in many details (Wullimann 2000). More specifically, all tetrapod brains possess a median, medial and lateral reticular formation inside the medulla oblongata, pons and ventral mesencephalon, including a noradrenergic locus coeruleus, serotonergic raphe nuclei and a medial ascending reticular activating system. There is a corpus striatum, a globus pallidus, a nucleus accumbens, a substantial nigra, a basal forebrain/septum and an amygdala within the ventral telencephalon, a lateral pallium, homologous to the olfactory cortex of mammals, and a medial pallium, homologous to the hippocampal formation (at least Ammon’s horn and subiculum). This means that all structures required for declarative memory (or its equivalent in animals), emotions, motivation, guidance of voluntary actions and evaluation of actions are present in the tetrapod brain. These structures essentially have the connectivity and distribution of transmitters, neuromodulators, and neuropeptides in the different groups of tetrapods.

That’s all just a fancy-schmancy way of pointing out that humans inherited our capacity for emotion, intellect and consciousness from a long line of pre-human, and even pre-mammalian, ancestors. The discovery of mirror neurons in birds ought to demonstrate to us that the capacity for empathy was likely present in the common ancestor of reptiles and mammals, and is thus an ancient trait in most modern terrestrial species. Based on this evidence, I give amphibians and fish the benefit of the doubt, too.

I take it as a given that animals possess and are capable of all the mental traits that speciesists like to prop up as uniquely human, in order to justify our long tradition of exploiting nonhumans. Any claim to the contrary – no matter how sophisticated and no matter how ancient the philosophical tradition in which it is rooted – is simply mistaken, and does not need to be taken seriously. It’s just another kind of creationism.

And that’s the rub. In light of evolution, we are under no obligation to take speciesist ideas seriously. They are not entitled to any intellectual respect at all. And we need not treat them like they are. Our position towards them should be one of conversational intolerance; claims about the uniqueness of human suffering or consciousness are as nonsensical as claims that Elvis still lives, or that the constellations influence human actions. In the words of Pauli, they are not even wrong.

Rather than being defensive about the foundation of our ethics, more vegans should be openly dismissive of the contrary position, and shift the burden of proof where it belongs: onto the creationists who claim animals can’t think, feel, or suffer.

All this is the reason I rarely write long posts on ethics or philosophy. In my day-to-day thinking and action, the claims of speciesists simply get ignored. I don’t think about these ideas often, because they are a waste of time, just like the claims of Flat Earthers or crystal healers. And in the relatively few instances where I am confronted by such claims, I either make fun of them, shift the burden of proof to the claimant, or simply ignore them altogether, depending on the situation.

I realize that it doesn’t make sense for all animal advocates to do this at all times and places, and there is an important role for dialogue and persuasion -- I just don't see it as my role. I can’t help think that if a few more average vegans adopted this attitude, we’d make some headway in the larger culture, the way skeptics of other parts of religion have been doing the last couple of years.

At the very least, it's a lot more fun than philosophizing with creationists.

Best Paleoveganology Of 2011

2011-12-28T10:24:00.000-08:00

I picked up quite a few new readers in the last couple of months; welcome! For their benefit, and because it's that time of year, here are links to what I think are my best posts over the last 12 months.

Deep Time And The Sanctity Of Death

Listening To Pterosaurs

What, No Bugs?! -- Paleo-Diet Paper Reveals Glaring Blind Spot

Quite A Stretch, Mr. Darwin: Adaptation, Diet, And The Giraffe's Short Neck

Book Review: "The Animal Connection," By Pat Shipman

More On Miocene "Apes"

Did Veganism Kill The Nutcracker Man?

It's Curtains For The Expensive Tissue Hypothesis

Coming Up Short: Grain Blamers And Climate Flickers

Coming Up Short: Grain Blamers And Climate Flickers

2011-12-19T20:05:00.000-08:00

Correlation ain't causation! In my experience, paleo diet defenders are prepared to whip this comeback out at the drop of a stat, as though it's news to the rest of us. If the motto isn't your local broscientist's favorite retort to veg*ns citing health studies, it's got to be in his top 10. Or at least be his fallback position when otherwise stumped by the evidence. It often seems to comprise the whole of their argument against mainstream health research. Which is ironic, because the scalpel cuts both ways, especially where paleo's historical claims are concerned.

The paleo diet narrative is held up by two big-picture ideas: meat was essential to our evolution, and grain was a blow to our fitness. I've already shown how the "meat made us human" half of this meme fails to hold up under scrutiny. The meat-eating:big brain correlation looks less like causation every day. But how about the flip side of that claim: was grain really a death(ish) blow to the human race?

The basic claim here is that when Homo sapiens adopted grains into our lives through the invention of agriculture, it had a species-wide negative impact on our health and fitness. As evidence, grain blamers point to the infamous "Neolithic decline," the point in the fossil record when humans are markedly smaller than in previous times, and when researchers begin to note an increase in evidence of widespread nutritional stress and dental problems. This decline coincides geologically with the transition from the Pleistocene (the so-called "Ice Age") to the Holocene (the current geological period), which in turn coincides with increased grain consumption and invention of agriculture by humans (ca. 10,000 - 7,000 years ago). Hence, agriculture generally and grains specifically caused the decline.

But is correlation really causation in this case?

Here's how grain blamer Mark Sisson summarizes the evidence:

We in the Primal health community are quick to point out that agriculture reduced physical stature. Generally speaking, bone records indicate that Paleolithic (and, to a lesser extent, Mesolithic) humans were taller than humans living immediately after the advent of agriculture. Multiple sources exist, so let’s take a look at a couple of them before moving on:

According to one study on remains of early Europeans, prior to 16,000 BC, European males stood 179 cm tall, or 5’10.5″, and females stood 158 cm, or 5’2″. Between 8,000 to 6,600 BC, average heights had dropped to 166 cm for males. Heights fell even further in Neolithic populations, dropping down to 164 cm for males and 150 cm for females, only reaching and surpassing 170 cm at the end of the 19th century.

Another source found that Paleolithic humans living between 30,000 and 9,000 BC ran almost 5’10″, which is close to the average modern American male’s height. After agriculture was fully adopted, male height dropped to 161 cm, or 5’5.4″. Females went from 166.5 cm to 154.3 cm under the same parameters.

This is a pretty dramatic change, to be sure. But take a close look at the data from Sisson's first source: the Paleolithic-to-Mesolithic stature decline in males was 13 cm. From the Mesolithic to the Neolithic, male stature decline was only an additional 2 cm. No data for Mesolithic females is offered, so it's a bit harder to evaluate the claim based on that data set; nonetheless, we can reasonably assume a similar pattern held for female humans across the Paleolithic-Mesolithic-Neolithic transition. If you read carefully, you should have noticed that most of the stature decline (at least in males) happened before the invention of agriculture.

There's a similar pattern in Sisson's second source: from the Late Paleolithic to the Mesolithic, average male stature declines a total of 4.6 cm. Similarly, female stature from the same transition drops a total of 6.8 cm. But from the Mesolithic to the Neolithic, male decline is only 2.9 cm, while female decline is 4.2 cm. Again, in both cases, there's a bigger decline from the Paleolithic to the Mesolithic than there is from the Mesolithic to the Neolithic. People started getting smaller before the invention of agriculture.

To be generous, one could still argue that the stature decline was a consequence of the invention of agriculture, since the Mesolithic was a transitional period, and agriculture probably wasn't the result of a single eureka moment, but rather a long process of aggregate discoveries or inventions building on previous ones. As we got more sedentary and plant-dependent, we also got smaller. That is, maybe the two processes were a feedback loop.

Or perhaps something else was going on...

Sisson continues:

We know these changes to height also reflected worsened health, because with shortness came dental pathologies like caries, plaque, and decay, signs of arrested growth indicating instances of severe malnutrition, and skull abnormalities that stem from iron deficiency. People got shorter, sicker, and less healthy. Height wasn’t a cause of poor health, of course, but it was an indicator.

To his credit, Sisson doesn't say getting shorter is what made us sicker. His careful use of language here is commendable. But while it may be true that height is an indicator of health, this doesn't necessarily mean, as Sisson implies, that there's a causal relationship between agriculture, health and stature in prehistoric humans. Correlation ain't causation!

The pattern of pre-Neolithic stature decline isn't limited to Sisson's sources. There's evidence for it all over the Paleolithic fossil record. One study noted that the significant Upper Paleolithic-to-Mesolithic stature decline was correlated with a change in hunting strategies brought on by the invention of more efficient weapons and a shift to smaller, more docile game animals. This would extend the stature decline trend back to at least 50,000 years ago, an estimate that agrees with Ruff (2002), who notes that the trend of a decline in average body mass begins about 50 Ka, and is equivalent whether or not Neanderthals are included. Beals, et al., (1984) examining the fossil evidence from a thermoregulatory perspective, concluded that Homo have been de-encephalizing and getting shorter for about 100,000 years, which puts the start of the decline well into the Middle Paleolithic... quite a long time before the invention of agriculture.

Casting further doubt on Sisson's claim is the fact that this decline also struck culturally- and geographically-isolated hunter-gatherer populations who never invented agriculture. Brown (1987) and Brown (1992) examined a Pleistocene-to-Holocene decline in brain size and body stature in the Australian hominid record that's comparable to the one we see in Europe and central Asia. He noted that even if we can attribute the decline in the Eurasian record to agriculture, another explanation must hold for the Australian one, since agriculture was never invented by the prehistoric humans there.

And lest we be speciesist about this, it's worth noting that other taxa of animals went through a similar decline in stature and robusticity at the same period of time. A contemporaneous trend among bears and canids was the subject of a recent Ph.D. thesis at Duke University. Guthrie (2003) reported a pre-extinction rapid body size decline among Pleistocene horses in Alaska. Smith, et al. (1995) and Smith and Betancourt (1998) found that the Pleistocene-to-Holocene body size decline in woodrats is precise enough to be used as a paleotemperature proxy. Hill, et al., (2008) report that bison body size declined 15 to 20 percent from the late Pleistocene to the Holocene.

This multi-species pattern of body size decline was examined in great detail by Smith, et al. (2010), and their results were graphed on the table below. It covers the whole of mammalian evolution and diversification from our beginnings in the days of the dinosaurs up to the present, so this blog post's period of focus looks relatively small on the graph. Nonetheless, you can still see the pattern, especially if you look at the top half of the graph. The red line is the end-Cretaceous mass extinction that wiped out the non-avian dinosaurs. As you move rightward from this line, you are moving forward in time, approaching zero, which is the modern day. Just as you get to the end of the trendline, you'll see a curve downward. That's the transition from the Pleistocene to the Holocene. Mammals in general, not just humans, got smaller.

Humans are self-centered, as individuals as well as a species. When we study our history and pre-history, it's easy, for this reason, to miss the Mammalia for the Hominini. I can understand why Sisson and other paleo proponents focus so much on humans and their relatives; after all, I'm obsessed with Miocene hominoids myself, which is the same bias at work in a different way. At heart, we're all a bunch of navel-gazing monkeys. So it's only human (and probably also hominid and anthropoid, if not mammalian) to cast ourselves as the heroes and victims of natural history. But like all biases, this one can lead us into the realm of just-so stories, and I think that's what's going on here. When measured against the evidence and placed in its proper context, where Homo is just one of many mammals who weathered the terminal Pleistocene, Sisson's claim that "agriculture reduced physical stature" among humans falls apart.

So, just what the what was going at the terminal Pleistocene to make mammals come up short? Based on my cited sources, you've probably intuited by now that it has something to do with climate change, and you'd be right... though it's a bit more chaotic than you might suppose.

Popular conception of the "Ice Age" depicts long millennia of worldwide arctic climate, followed by a trend of slow warming, where glaciers retreat in stately fashion back towards the poles and mountaintops, while the earth blooms in their wake, making way for us navel-gazing monkeys to take center stage and invent awesome stuff like spears and rockets and LOLcats. In short, most people think of the Pleistocene-Holocene transition as a move from steady cold to steady warmth. But in reality, it was more like a shift from screamo to Stradivarius.

At right is a snapshot of oxygen-18 isotope signals from a Greenland ice core sample (from Ditlevsen, et al. 1996), showing the climate patterns of the late Pleistocene and the early Holocene.

The low pass filter data shows that the Holocene is much less variable than the Pleistocene on time scales of 150 years or more. The high pass filter data shows the same thing on scales of 150 years or less. Ice cores like these can show climate fluctuations on a scale down to the decade level, giving us a pretty precise idea what climate was like in past times, at least for about the last 400,000 years or so. There's a large body of data from across the world, and using multiple indices and proxies, that corroborates the pattern seen in this graph (much of it cited in Richerson, et al., 2001). Most of the data at this resolution from the Pleistocene-Holocene transition shows that the Pleistocene was a period of chaos, with the climate see-sawing from one extreme to the other, often on human time-scales. The terminal Pleistocene was characterized by rapid climate flickering, with climate shifting decade-to-decade from cold and dry, to less cold and wet, and back again. Under these conditions, widespread droughts, devastating floods, massive wind storms and other climate extremes that modern people experience perhaps once a century would have been a lot more frequent, happening every 10 years or so in many places.

So, it's not just that the world was getting warmer, and animals getting smaller as a result (see Bergmann's rule and Allen's rule). It's also that the global climate was stabilizing after a long period of upheaval and chaos. The profile of selective pressures faced by our ancestors was changing in spectacular ways. That has some profoundly interesting implications for our understanding of the origins of agriculture, and raises some questions about the second part of Sisson's claim -- "with shortness came dental pathologies like caries, plaque, and decay, signs of arrested growth indicating instances of severe malnutrition, and skull abnormalities that stem from iron deficiency."

And You Thought I Forgot...
Let's get one thing settled before moving on. It's true that the human skeletal record changes dramatically at the Neolithic transition. The symptoms Sisson highlights are really there. The reasons why, though, are a bit more complicated than he makes them out to be.

Taking a few steps back and returning to the end-Pleistocene (aka, the Middle to Upper Paleolithic) for a moment, one thing becomes starkly apparent: agriculture would have been impossible in most places. Richerson, et al., (2001) note that the rapid climate fluctuations, low atmospheric CO2 content, oscillating atmospheric dust content, lower average rainfall, and various other chaotic environmental patterns of the end-Pleistocene posed an insurmountable network of interlocking constraints on any attempt to create a sedentary, pastoralist culture. Farming simply couldn't have been done, even if someone had been inclined to invent it. And there is some Paleolithic evidence that many cultures were, in fact, so inclined.

As Richerson, et al., note, the invention of agriculture in Neolithic societies was always preceded by an intensification of subsistence and increased reliance on the processing of low-quality plant and small game resources. But the Neolithic isn't the only time we see this in the record. An increase in plant-heavy subsistence patterns seems to be associated with climate pulses favoring warmer, wetter conditions across the Paleolithic and Mesolithic. The most famous, cited by Richerson, et al., is the Natufian culture of the Levant, who exploited a brief warm period in the Upper Paleolithic to become a semi-sedentary culture relying heavily on small game and grain foraging, along with nuts and fruits. When the Pleistocene climate flickered again and plunged the Levant back into a cold, dry period, the Natufians reverted to traditional hunting and gathering (Stutz et al., 2009). Only when the climate stabilized in the Holocene was the apparent human proclivity towards agriculture really able to take seed; in some ways, the Neolithic "invention" of agriculture wasn't really new at all.

The stable, warm, wet climate of the Holocene exerted a selective pressure for smaller phenotypes among most animals, not just humans. And humans in this situation did what they seem to have done many times before: shifted their trophic strategy to focus on more plants and smaller animals, a strategy that was probably homologous with their australopithecine and even earlier hominoid ancestors.

So far, so good. But what about Sisson's point? We didn't just get smaller, we also seem to have gotten sicker. Does agriculture, in and of itself, explain this? Were grains, in and of themselves, really to blame here?

Sisson's strongest case in this regard is probably the tooth problems. Most researchers agree that the increased carb intake of Neolithic societies played a role in the observed increase of dental caries, plaque and decay. But, there's a positive consequence here, too: Neolithic teeth have less wear than Paleolithic ones, because eating soft food places less stress on the chewing surfaces. This means less energy expended on food processing and, ultimately, on digestion.

Next is "signs of arrested growth indicating instances of severe malnutrition." Again, we can file this under "true, but misleading." Neolithic agriculture is characterized not simply by the adoption of grains, but (I'd argue) more importantly by over-emphasis on one or a few grain resources to the exclusion of other plants: rice in Asia, millet and sorghum in Africa, wheat in Europe and central Asia, corn in the Americas. Sisson's implied formula of "eat grains = get sick" isn't quite on the mark. It ought to read "specialize diet = improve chances of sickness." As diets diversify and societies become more adept at mixing various foods, health improves. There's no good reason to think a varied modern diet centered on whole foods -- whether omnivore or vegan -- is less healthy than anything cavepeople ate.

Finally, we have iron deficiency. This is actually the weakest of Sisson's points. I suppose he's trying to imply that agricultural foods necessarily increase risk of iron deficiency anemia. I call this a lack of imagination and a clear example of confirmation bias. After all, even in the modern world, helminth parasite infection is one of the three leading causes of iron deficiency anemia. Given that even the most impoverished developing communities today have access to more sanitary conditions than their ancestors did, there's no good reason to think that hookworm and other helminth infection rates would have been any lower among prehistoric peoples; in all likelihood, they were much higher than today. Skull abnormalities and other skeletal problems in Neolithic bodies might be evidence of nutritional deficiency... or they might be evidence of hookworm epidemics. Or, for that matter, of malaria, another leading cause of anemia. Most likely, some combination of these three factors explains the Neolithic skeletal record.

(As an interesting side note, helminth parasites eat cholesterol and counteract atherosclerosis, which might be part of the explanation for the lower lipid profiles of hunter-gatherer peoples.)

But there's another possible explanation for signs of increased iron deficiency in Neolithic skeletons, and ironcially, it points to what's actually pretty great about agriculture from an evolutionary point of view. That explanation is pregnancy.

The Neolithic witnessed a dramatic increase in birth rates among pastoralist populations. Because pregnancy imposes greater iron demands on women, and because women were having more babies in the Holocene, it's fair to hypothesize that the increase in signs of iron deficiency among Neolithic peoples reflects a failure of nutritional innovation to keep pace with improved fertility. And it's fertility that really matters here.

Evolution is fundamentally about sex, not food. Survival to reproductive age and production of offspring are the bottom line, and traits or behaviors that improve chances of success on these fronts will be selected for, while those that don't will be selected against. Selective pressures in the Holocene appear to have favored smaller, less robust human phenotypes, and agriculture is the strategy we invented to overcome those pressures. And we did it dramatically well. Everything else is a trade-off.

Seen in this light, agriculture is probably the single greatest boon humans have ever experienced to our fitness. It's what enabled us to survive the new Holocene selective pressures and expand our range to every corner of the world, inventing awesome stuff like spears and rockets and LOLcats along the way. That's not to say we didn't mess things up, too, and it would be crass to ignore the negative impacts we've had on the world and each other, let alone to justify them. But even these infractions are consequences of our fitness, not a demonstration of our lack of it.

The claim that agriculture caused a decline in human stature doesn't hold up to the evidence, and the indictment of grains, in and of themselves, as a detriment to human fitness is far too simplistic to be taken seriously. Correlation ain't causation, grain blamers.

Sources
-- Beals, K.L., Smith, C.L., and Dodd, S.M. (1984). Brain size, cranial morphology, climate and time machines. Current Anthropology 25: 303-330.
-- Brown, P. (1987). Pleistocene homogeneity and Holocene size reduction: the Australian human
skeletal evidence. Archaeology in Oceania 22, 47–71.
-- Brown, P. (1992) Recent human evolution in East Asia and Australasia. Philosophical Transactions of the Royal Society B 337, 235–242.
-- Ditlevsen, P.D., et. al. (1996). Contrasting atmospheric and climate dynamics of the last-glacial and Holocene periods. Nature 379, 810-812.
-- Guthrie R.D. (2003). Rapid body size decline in Alaskan Pleistocene horses before extinction. Nature 426, 169-171.
-- Hill, M. E., M. G. Hill, et al. (2008). Late Quaternary Bison diminution on the Great Plains of North America: evaluating the role of human hunting versus climate change. Quaternary Science Reviews 27, 1752–1771.
-- Richerson, P.J., Boyd, Robert and Bettinger, R.L. (2001). Was agriculture impossible during the Pleistocene but mandatory during the Holocene? A climate change hypothesis. American Antiquity, Vol. 66, No. 3, 387-411.
-- Ruff C.B. (2002). Variation in human body size and shape. Annual Review of Anthropology 31:211–232.
-- Smith, F.A., Betancourt, J.L. & Brown, J.H. (1995). Evolution of body size in the woodrat over the past 25,000 years of climate change. Science 270, 2012–2014.
-- Smith, F.A. and Betancourt, J.L. (1998). Response of bushytailed woodrats (Neotoma cinerea ) to late Quaternary climatic change in the Colorado Plateau. Quaternary Research 50: 1-11.
-- Smith, F.A., et.al. (2010). The evolution of maximum body size in terrestrial mammals. Science 330, 1216-1219.
-- Stutz, J.A., Munro, N.D., and Bar-Oz, G. (2009). Increasing the resolution of the Broad Spectrum Revolution in the Southern Levantine Epipaleolithic (19–12 ka). Journal Of Human Evolution. doi:10.1016/j.jhevol.2008.10.004

Quote Of The Unit Time

2011-12-15T14:25:00.000-08:00

"It's funny how Denise Minger 'debunked' The China Study just to do a diet in many ways similar to the one described in the book. High plant based diet, low in animal products. The point was?"

-- DarkLixuz

at Paleo Debunked

A Definitive Critique Of The Paleo Diet

2011-12-09T19:42:00.000-08:00

Debating paleo dieters is often like debating creationists: sometimes, it's hard to know where to begin, their misunderstandings of evolutionary theory are so fundamental. When dealing with both crowds, I often feel I need to teach them a remedial course in evolutionary biology just to make sure words mean the same things to us. It's wearying and, for an undergrad like me, often a complete waste of time.

But thankfully, someone has taken the time to assault the entire paleodiet ideology from its foundations all the way up to its particulars. Below is the first installment of a brilliant video series by a YouTuber who goes by the handle of Primitive Nutrition. It'll give you a taste of how deeply paleo dieters misunderstand the basics of science and the major concepts in evolution. At the time of this post, I've watched four of the guy's videos, and am mightily, mightily impressed.

Watch the whole series. I'm going to, cuz I suspect it's worth every minute.

It's Curtains For The Expensive Tissue Hypothesis

2011-11-23T20:58:00.000-08:00

From my previous post, you already know what a poor attempt at debunking the paleo diet looks like. Now, I figure I owe you an example of how to do it right. Call this a Thanksgiving present.

"Energetics and the evolution of human brain size," published earlier this month in Nature, tests and refutes the expensive tissue hypothesis. It's impressive work, and pretty devastating to the hypothesis that has provided a rhetorical foundation to the paleo diet mythology for over a decade now.

Navarrete's, et. al.'s, main findings (further details below) are:

There is no negative correlation between brain size and gut size in any mammalian taxa, refuting the ETH's prediction to the contrary;
There is, however, a strong negative correlation between brain size and adipose tissue deposits; that is, fatter animals have smaller brains than lean ones; and,
Humans are seeming exceptions to this rule because our fat deposits don't interfere adversely with our means of locomotion, thus freeing up energy for encephalization that other primates have to use for carrying around all that fat.

And the stunning thing about this paper is that the authors didn't simply test the ETH using new data, but also re-tested the data from the original paper using newer statistical methods and controlling for confounding factors that that Aiello & Wheeler missed, for whatever reason.

Their conclusion: when adiposity, phylogenetic relationships, sample bias and sex differences are controlled for, Aiello's & Wheeler's original data don't support their hypothesis any better than the newer data does! In short, the ETH is wrong at the foundation, not just at the margins.

But, you should still hold your applause for a moment, so we can make clear not only what this paper is, but also what it is not.

It is not evidence that pre-humans were strict vegans. It is not evidence that Homo sapiens are natural herbivores. It is not evidence that meat and dairy, in themselves, are intrinsically either good or bad for us. If you're the kind of vegan who looks for an evolutionary hook to hang your fall-from-grace fantasies on, you'll have to look elsewhere. Prehistoric humans and their ancestors ate meat, and sometimes a heck of a lot of it. You'll just have to deal with that.

However, the paper is pretty good evidence that meat wasn't essential to our evolution. Meat, it turns out, probably didn't make us smart, after all. At the level of vegan blogosphere debate ammo, that might be cause for some applause.

The Original Problem
To understand how the ETH came about, how thoroughly Navarrete, et. al., have undermined it, and on what grounds they have done so, it's probably a good idea to hop in the Wayback Machine and understand what Aiello & Wheeler were trying to explain in the first place.

The $64,000 question in paleoanthropology (adjusted for inflation) for the last 80 years or so has been, "why can humans have such freakishly huge brains compared to other primates their size, but still have the same basal metabolic rate?" The question is rooted in a biological principle called Kleiber's Law, which demonstrates that the metabolic rate of most animals scales to the 3/4 power of their mass; this law holds true across the animal kingdom, and appears to function in plants and bacteria, too: even within individual cells themselves! Kleiber's law can be used to precisely calculate the metabolic rate of any animal just by knowing their total mass. In short, it shows that animals of roughly the same size will have roughly the same basal metabolic rate (BMR), and that's where the problem with humans comes in.

It turns out that within an animal, the metabolic rate is not evenly distributed among all its tissues. Some tissues -- brains, hearts, lungs, livers, the GI tract, to name a few -- use more calories than others; they are thus "expensive." Every organ has its own individual metabolic rate. So, even though animals of equal size will have equal overall BMRs, they won't necessarily allocate that energy to their organs in the same way.

Let's say you have two species of roughly equal mass. One of them is characterized by a super strong heart, and the other by advanced lung capacity. Hearts and lungs both use a lot of energy, so each species will allocate its overall BMR to its distinct tissues in different ways, but will still have the same total BMR as the other. This means that without a change in overall mass, the strong-hearted species can never have the amazing lungs of the strong breather, and vice versa. Kleiber's law must hold, and to do that, some organs and tissues have to take priority over others. So long as their overall BMRs remain the same, different species of equal mass can display a lot of variation in the ways their individual tissues consume energy.

This is the crux of the human brain problem.

Using Kleiber's law, Aiello & Wheeler noted that an 80-lb. australopithecine would have had roughly the same BMR as an 80-lb. Homo sapiens, despite the difference in their brain sizes. The human brain would have 4 to 5 times the metabolic cost of the softball-sized australopith brain. So, Aiello & Wheeler reasoned, in order to maintain the BMR predicted by our mass, humans must have made a trade-off between competing tissues at some point in our evolution; i.e., as our brains gobbled up more energy, some other set of tissues had to get less, and thus shrink over evolutionary time. Something had to give.

After assessing the cost and importance of various tissues within modern humans, Aiello & Wheeler concluded that the human tissue most reduced in comparison to other primates was the GI tract. As our brains got bigger, our guts got smaller. As a result, we had to become dependent on more high-quality, nutrient-dense, easily-digested food than other primates to maintain the high cost of our brains, since our reduced guts could no longer handle the sorts of food on which our ancestors had subsisted for millions of years. They proposed that the most likely reliable source of such calories was meat and other animal products. A dramatic increase in animal matter in the hominin diet eased the energy constraints imposed by nature on big brains, and allowed our brains to grow to massive proportions without violating Kleiber's law.

In the popular press and later, in the blogosphere, the short hand version of the ETH became, "meat made us smart," or "meat-eating made us human." But that's not precisely what Aiello & Wheeler were claiming, and the difference between what they claimed and what carnists who cite them claim is crucial to understanding what Navarrete, et. al., have accomplished with their new paper.

For the ETH, meat itself wasn't really the point. Though Aiello & Wheeler proposed it as the probable source of the necessary calories, they hinted that other high-quality foods, like sugary fruits, tubers, or oil-rich nuts and seeds, could also have done the job. A close reading shows that the ETH was fundamentally about total calories, not specific calorie sources. Even so, the prominence of meat-eating in the paper supplied de facto legitimacy to several paleofantasies about the necessity of meat to the human diet, one of which would become the modern paleo-diet movement.

But more fundamental to the ETH than meat-eating -- indeed, the whole point of the paper -- was the claim that Kleiber's law is maintained through a necessary trade-off between expensive tissues within a given organism, in this case Homo sapiens. Increased meat-eating was merely a consequence of this claim, not the foundation of it. And for the last 15 years or so, the argument over whether meat was important to our evolution has obscured the more fundamental -- and eminently more testable -- claim of an expensive tissue trade-off.

Any good hypothesis can produce at least one testable prediction. And the ETH has one, right there for everyone to see (though it's been astonishingly ignored for 15 years). If the ETH is true, we should expect to find a tight negative correlation between brain mass and the mass of other expensive tissues across a range of taxa, not just among primates. And it's this prediction, not whether cavemen were meat-eaters, that Navarrete, et. al., set out to test.

The Fat Of The Matter
The key way they tested the overall hypothesis across various mammal groups was controlling for adipose tissue deposits in their calculation of a given animal's mass. In short, they omitted fat deposit mass from all specimens, eliminating it as a variable. This was an important control tactic (and one not used by Aiello & Wheeler in their original paper), because adipose mass varies by season and habitat among many species, and can thus be a major confounding variable. Only by eliminating it altogether and testing brain size against fat-free body mass, the authors reason, could a possible trade-off between tissues be reliably detected.

Under these conditions, no negative correlation between brain size and digestive tract mass was found. In fact, no negative correlation was found between brain size and the mass of any expensive tissue. The authors did, however, uncover a tight negative correlation between brain size and adipose tissue depots: the fattest species had the smallest brains.

Given Kleiber's law, this might at first look like a dilemma: fat tissue doesn't use a whole lot of energy, so why would it constrain brain size? The answer is that it costs an animal a lot of energy to lug the extra weight around, especially while climbing or running. And it's here that humans -- along with whales and seals -- have an advantage: fat stores don't significantly interfere with our ways of getting around. Bipedalism and dorso-ventral flexion (the swimming method used by cetaceans and pinnipeds) are simply more efficient ways of moving.

To understand just how big of an impact bipedalism has on human energy expenditure, take a look at the paper's Supplemental Material, and its discussion of the different energy costs that excess fat imposes on humans and chimpanzees. Human foragers spend between 18 to 22 percent of their daily energy on locomotion. Chimps have a comparable but somewhat larger range of 16 to 30 percent. But, because of the different ways they move around, a 10 percent increase in body fat deposits for humans means only a 1 percent increase in needed energy, while for chimps it means a 2 to 3 percent increase.

In other words, it costs chimps twice to three times as much energy to move around the same amount of body fat as a human. Further complicating the matter is that the energy cost of travel during climbing for primates is almost directly proportional to body mass. Quadrapedal terrestrial walking and briachiation as modes of transport simply impose higher costs on primates than does efficient bipedalism. This energy cost adds up over time (especially evolutionary time), and thus can constrain the total amount of BMR available for encephalization.Thus, because humans save so much energy by being bipedal, they can store relatively large amounts of adipose tissue and still grow big brains.

Digging Up Old Data
If Navarrete, et. al., had stopped there, they'd have a pretty strong case: the ETH's predicted negative correlation between brain size and organ mass appears not to exist, at least among mammals. But, they took their investigation a step further and decided to re-test Aiello's & Wheeler's original data set, controlled for several compounding factors that Aiello & Wheeler hadn't accounted for. And that's where the real knock-out punch to the ETH happens.

As detailed in the Supplemental Material, Aiello & Wheeler were working with a data set that had a couple of problems. Namely, it was biased towards catarrhine primates over platyrrhines; it didn't control for sex differences between members of species with marked sexual dimorphism (sexual size dimorphism affects body mass more than brain size), or for differences in the body mass of wild vs. captive specimens of the same species; and it didn't account for phylogenetic relationships between various hominid species (a fact I have pointed out before).

In fairness to Aiello & Wheeler, most of this was beyond their control. 15 years ago, for instance, we didn't know that Paranthropus was a sister taxa to Homo rather than a direct ancestor, and the literature on primate body masses simply didn't contain as wide a sampling of platyrrhines as it does today. Aiello & Wheeler did the best they could with what they had.

Nevertheless, Navarrete, et. al., were able to identify and control for these confounders in a new test using the latest phylogenetic statistical methods on the original data sample. And the results did not support Aiello's & Wheeler's hypothesis; even their own data failed the ETH in the end.

Taken together with the new author's own data, these re-testing results pretty much have put the ETH down for the count. If they want to save it, Aiello & Wheeler will have to tackle Navarrete, et. al., with much more rigorous data and analysis than they used the first time around. Make no mistake, this is a quiet revolution in action.

What this means to the vegan blogosphere is that there is now a robust and scientifically credible argument against the claim that meat-eating was essential to our evolution... and the case has nothing to do with animal rights or other aspects of vegan ethics. That being said, this paper cannot and should not be used as evidence that hominins did not eat meat at all, or that pre-human ancestors were purely frugivorous. If we do that with this paper, we'll be just as guilty of building a paleofantasy as the caveman dieters were when they turned the ETH into their shibboleth.

So, while you're dining on Tofurkey or some African pumpkin stew (my planned Thanksgiving meal) this holiday, and obnoxious Uncle Carnist breaks out the old meat-made-us-human canard for the millionth time, feel free to take him to the mat. He's had it coming for years.

The Great Paleo-Diet Debunking That Wasn't

2011-11-03T23:59:00.000-07:00

I've been getting a lot of emails about anthropologist Barbara J. King's critique of the paleo diet on NPR last week. I have to admit, I was intrigued: I've long been rubbing my mittens over the prospect of an expert on human evolution giving the paleo-eater crowd a swift kick in the loincloth. So, I penciled in some free time between my human mate-choice experiment and my ecology final project, took a few soothing deep breaths of anticipation, and sat down to savor some fresh thinking from a rigorous skeptic.

What I got instead was a shibboleth-rattling worthy of the finest witch doctors. Now, I expect this kind of hand-waving from the post-modernism-clouded minds of the cultural anthro crowd, but I thought King was a biological anthropologist. I was hoping for at least a few points about biochemistry and fossils, comparative anatomy and hominoid baggage. Heck, even a few leading questions, however misleading, about endogenous cholesterol production or amylase or eneterohepatic B12 recirculation would have been nice.

But come on, this? A missive that barely rises above the quality of evidence or logic in a typical blog comment from the president of the local high school vegan club?

I'm still reaching for the Excedrin.

It's not that King isn't making some valid points about hominid evolution. On a superficially factual level, much of what she says about that subject accords with what I've been taught, and what you'll read about in the paleo-anthropological literature.

It's just that she hasn't written a critique of the paleo diet movement. King is attacking a straw man.

Don't get me wrong; I have my own problems with the paleo diet's fundamental claims. But, the way I see it, the first duty of a skeptic is to understand the opponent's case honestly, on its own terms. And King fails at this duty; whatever else she thinks she is critiquing here, it's not the paleo diet movement I've come to know since I started this blog.

I spend some of my spare time lurking on paleo blogs, commenting on articles or videos here and there, but generally just trying to get a feel for what the movement is really all about. And it's obvious to me that King hasn't done this, or at least that she wasn't paying sufficient attention when she tried to do so.

For one thing, she seems to confuse the paleo movement with the low-carb movement. True, there is some overlap between the two groups, but paleo-eating isn't necessarily, or even primarily, carb-phobic. Some paleo bloggers defend high-carb diets similar to that of the Kitavans.Others are quite fond indeed of high-fruit eating plans. On the whole, low-carb isn't essential to the paleo philosophy.

What unites the paleo movement, food-wise, is an aversion to grains (especially refined) and refined sugars. Basic paleo doctrine is that the Demon Grain is out to get you, and if you're not careful, you'll end up with wheat belly or celiac, or both. It's true that grain products are high in carbs, but not all carbs are grains, and King -- a biological anthropologist, remember -- should not need an anonymous undergrad blogger like me to remind her of this.

For another thing, her remarks about the unsustainability of paleo-eating in a world of 7 billion people miss the point, too. Few paleo-eaters adopted the diet out of ethical or environmental concerns, as far as I can tell; most seem motivated primarily by personal health and a nebulous notion of "optimality." And further, though most paleo-eaters are enthusiastic about their diet choices, few of them make universalist claims or say that it is a blueprint for global civilization. Quite the contrary, politically-conscious paleos have a distinctly locavore bent, while most paleo blogs I've ever read are distinctly apolitical, avoiding global-ethics questions like wheat with the plague, unless some snotty vegan tries to corner them on the subject.

This is not to say that the paleo-diet's claims don't carry global ethical implications, even ones they may not see; but, an ethical critique of the movement would at the very least need to spell these implications out, rather than pretending that it's explicitly based on ethics or politics. And in any case, by taking this approach, King is lending her scientific credentials to a set of ethical claims that don't necessarily follow from her expertise. It's pure appeal-to-authority.

For a third thing (are we done yet?), King's scientific point misses the mark by almost an entire epoch:

Our ancestors began to eat meat in large quantities around 2 million years ago, when the first Homo forms began regular use of stone tool technology. Before that, the diet of australopithecines and their relatives was overwhelmingly plant-based, judging from clues in teeth and bones. I could argue that the more genuine "paleo" diet was vegetarian.

She seems to be unaware that the "paleo" in paleo-diet is short-hand for "Paleolithic," not a general attempt to co-opt all of paleo-anthropology in the service of a fad diet. The paleo diet's focus is, for the most part, precisely on the period of time she attempts to hand-wave away by diverting the reader's attention to the Pliocene. Again, the paleo movement's claims about and extrapolations from the Paleolithic may be pseudo-science, but leading us back before the Paleolithic in this way does nothing to demonstrate why.

King's tactic here glosses over the significant morphological changes of the last 2.6 million years, that paleo adherents consider supremely important. It is certainly true that H. sapiens retain within themselves the 22 Ma-old basic hominoid body plan for arboreal omni-frugivory; but at the same time, we are none of us Proconsul any longer, or even Australopithecus. Much of what morphologically distinguishes the Homo clade from its forebears reflects greater exploitation of, and selection for, a more omnivorous trophic strategy. Bottom line: humans really are better at handling meat than other primates seem to be, at least among extant species.

Implying otherwise is an amateur mistake. While it's excusable coming from the president of the local high school vegan club, King really ought to know better than this. The veg*n cause isn't served by obfuscation, and doesn't depend on paleo-fantasies. That humans can handle meat better than other primates does not mean we can't or shouldn't be vegans; after all, there's still all that hominoid physiology and biochemistry knocking around inside us (a point I think many paleo critics of veg*nism often forget), and we do share a capacity for suffering with other vertebrates that ought to inform our ethics.

On the whole, it just seems to me like King didn't do her homework, and relied instead on pop media reports (and perhaps even the blasphemous Wikipedia) to inform her about the paleo diet movement. The result, though I doubt she intended it, is a dishonest misrepresentation of that movement. If I were on her graduate committee, I'd send this one back for revision.

King had a great opportunity here to skeptically examine the philosophical underpinnings of the paleo diet through the lens of evolutionary biology, and she blew it. Which is too bad, because her easily-refutable argument, coming as it does from an expert source, will leave many readers with the impression that there is no such critique to be made, and that scientists who object to its claims are merely agenda-driven.

The problem with the paleo-diet philosophy, from the perspective of evolutionary theory, is really a no-brainer: like some strains of veganism -- and indeed, like nearly all other "diets" -- it fetishizes food as both the problem and the solution. Almost without exception, paleo-eaters claim that the problem with "Neolithic" foods like refined grains and sugars is that these foods are at odds with our biology. We are not "designed" to eat them, and thus suffer the diseases of civilization as a result. Therefore, the claim goes, we should eat the way our Paleolithic ancestors ate.

And to be sure, some foods are worse -- a lot worse -- for us than others, at the level of individual health. But that's not because those foods are at odds with our biology so much as that they are in accord with our instincts.

See, contrary to what paleo-eaters claim, modern humans do eat the way our ancestors did. In fact, we eat exactly the same way they did; that's precisely the problem. Humans are instinctively driven to eat as much as we can when food is plentiful, so that we can build up and store fat as an insurance policy for lean times. And we are biased towards calorie-dense foods whenever they're available, because they give us the biggest payoff for the least work.

This makes perfect sense for us, given the context of our evolution. It's a great strategy when your chief concerns are avoiding starvation/predation, but absolutely shitty when safety is assured and food is overabundant. And even more so when the food that takes the least effort to procure is also the worst for you.

This strategy is older than humans, older than primates, older even than mammals. It's been the way of all animal life since at least the Cambrian explosion. And it's this deep-time perspective the paleo-diet lacks.

The diet works for the same reason that all well-designed diets work: because it gets us to reign in our instincts, to eat against the grain (pun intended) of our natural ways. To exercise some discipline in food choices, rather than simply following where our instinct leads us. "Paleo" diets are a completely modern response to a completely modern phenomenon: the intersection of our natural gluttonous instincts with the rapid increase of physical safety and high-calorie food overabundance. It shares this modern status with veganism and all other diet plans, well-designed or not. In short, it really has no place calling itself "paleo" anything.

The "paleo" diet is as "Neolithic" as they come.

The Trouble With "Speciesism"

2011-10-20T10:52:00.000-07:00

I can count on less than one hand the number of times I've ever used the word "speciesist" as a pejorative for someone who believes in human supremacy. I mean, let's face it, it just doesn't have the same pizzazz as "racist" or "sexist." Maybe it has too many syllables (though that doesn't seem to hurt "homophobia"); maybe an alternate name would be better. Taxonist? Cladist? Human Supremacist?

But there's a problem with "speciesist" aside from its clumsiness: it's counter-intuitive. It implies an equality of species that most humans are simply incapable of accepting. And that's an obstacle that repeated use of the word may not be able to overcome.

I've never much used the word for this very reason. Most people already agree that killing and hurting animals unjustly is wrong. Most people already have a sufficient-enough level of cross-species empathy that they can intuit why factory farming is wrong. There really isn't much need, in my view, to invent a whole new ethical system to promote veganism. We really just have to get more humans to take their own professed values seriously, and to think before they eat.

Every species is different from all others in fundamental ways. That is what it means to be a species. And while it's true that this fact alone is not enough to justify the horrid things we do to nonhuman animals, it's also not an ideological construct in the same way that, say, race or gender are. Humans and nonhumans really are fundamentally different, and the farther afield one gets from our clade, the more pronounced those differences get. Pretending these differences don't exist, or that they are irrelevant in ethics, is to my mind a losing battle.

I've always thought of the issue in these terms: animals have interests of their own, independent of how our species feels about them. And animals should be left alone to pursue those interests; the benefit of the doubt should go to them in situations where our own species or individual interest is not in conflict with theirs. When our interests are in conflict, those of animals ought not be dismissed simply because they are nonhuman.

In practical terms, this is a more than sufficient case for veganism: for most people living today, exploiting animals for food is completely unnecessary. That they taste good and are made convenient to us are not just cause for overriding animals' interests in themselves, and certainly not for the hell we inflict on them with modern farming practices.

While we're on the subject, I've only rarely ever used the phrase "animal rights," too, and for much the same reason I've avoided "speciesist." My view has always been one of a more laissez-faire approach to animals than a social contract: just let them alone, and leave them free to pursue their own lives and interests.

Does this make me an animal libertarian?

Skeptical Vegan Vs. Frankenfoods!

2011-09-17T11:48:00.000-07:00

The Skeptical Vegan has (bless him) saved me a lot of work by starting a new series on GMOs & genetic engineering. It's high quality work, and not to be missed.

If you haven't already, you should subscribe to his blog right now.

Starved "Vegan" Baby Prosecutor: It Wasn't Veganism At All

2011-09-17T11:44:00.000-07:00

I admit, I haven't closely followed the case of the Atlanta vegan couple who starved their baby to death, but I've had to be harangued about it on several occasions. So, I thought it worth pointing out a statement issued by the prosecutor in the case:

"No matter how many times they want to say, 'We're vegans, we're vegetarians,' that's not the issue in this case," prosecutor Chuck Boring said during the trial. "The child died because he was not fed. Period."

Interestingly, it was the defense who argued that the baby died as a result of his parents' vegan ideals. The prosecution, however, argued that veganism wasn't the issue. Seems the judge and jury agreed.

Why can't the rest of the meaty-mouthed world?

Dino Feathers In Amber

2011-09-16T20:55:00.000-07:00

Described in today's issue of Science, the feathers from avian and non-avian dinosaurs date from the late Cretaceous. Some absolutely breathtaking photos, too.

B12 & Human Evolution

2011-09-10T10:23:00.000-07:00

The latest dose of Vegan Outreach contains an interesting question:

After I mentioned that vegans must rely on fortified foods or supplements for vitamin B12, this person cited that fact as evidence that nature intends for humans to consume animals or animal secretions. This person's point had me incapable of responding. What is your take on this comment?

I get this a question a lot, too, and there are a couple of ways to handle it. One is the way Jack Norris responded with, an entirely appropriate pointing-out that nature does not "intend" anything. In most cases, that suffices.

Problem is, it sometimes comes off as slightly dismissive, if not evasive. So, I have come up with another, equally valid response.

"B12 deficiency is a common problem even for meat-eaters. The Framingham Study determined that up to 40 percent of Americans have 'sub-optimal' B12 blood levels... and vegans are not 40 percent of America. So, it's a common dilemma, but fortunately, nature has engineered a way around it: the technical term is enterohepatic circulation. It's a mouthful, but all it really means is that once you have sufficient B12 stores, your body continuously recycles it through the bile system, keeping you at functional levels for years, sometimes decades. We should not rely on this by any means, but it's a fallacy to argue that because we need supplements or fortified foods to get B12, nature therefore 'intends' us to eat meat. Nature also engineered us to survive a long time without any external B12 sources. So the issue really comes down to ethics and free will, not the laws of nature."

I've tested versions of this response out on some evo-savvy interlocutors, and it works almost every time. For those who want evidence, I point out that the process is present in monkeys, indicating that enterohepatic circulation of cobalamin has likely been ancestral to our lineage since before the appearance of the Miocene "apes" about 22 Ma.

Having said that, though, I'm neither a doctor nor a dietitian, so turn to Jack Norris and Ginny Messina for any health-related questions.

Vegan Scientist Link Love

2011-09-02T23:47:00.000-07:00

Vegan Scientist has a brilliant and cleverly-written post up today about the idea of "cruelty-free" meat. Read it and weep, laugh and reach for the Excedrin all at once.

More Embarrassing Science Reporting

2011-09-02T11:28:00.000-07:00

Courtesy of the International Business Times: Researchers Tap Into Cold Resource; Discover Ancient Woolly Mammoth Rhino.

Of course, rhinos and mammoths are completely different species. There's no such thing as a "woolly mammoth rhino."

Though I suppose it's more plausible than a sharktopus.

Did Veganism Kill The Nutcracker Man?

2011-08-27T18:05:00.000-07:00

The short answer is, "no." I almost filed this one under Idiotic Omnivore Claims, but realized that wouldn't be fair. The misunderstanding is just a function of how slowly scientific information gets spread into the public consciousness.

And now, you're wondering what I'm talking about.

The Claim: Paranthropus robustus was driven to extinction because its specialized "vegan" diet prevented it from adapting to changing climate. Or so I was recently informed by manowar40 in a YouTube comments section. His contention is that Homo was able to adapt to drying climate because of our omnivorous diets, while P. robustus was so dependent on a "vegan" diet that it died out.

It would be easy for me to dismiss this as just another misinformed omnivore on his high horse, but that's only because I'm a geek who reads paleontology journals. In other words, he doesn't follow all the latest research, and just relies on informed third parties to fill him in. And there's nothing wrong with that; it doesn't make him a dumbo at all.

It's just that his sources, whoever they are, are a bit behind the times.

True, it used to be the consensus that P. robustus died off because of a specialized diet. The reason for this assessment is that the paranthropines had big, flat, thick-enameled molar teeth and huge jaws, usually a sign of specialization to hard, brittle foods like nuts and seeds (hence, the nickname "Nutcracker Man," given to P. boisei, a close relative of robustus). Genus Homo has more generalized masticatory adaptations, reflecting a wider variety of food strategies.

Or so the reasoning used to go. That was before we started doing laser ablation stable isotope analysis, a method that allows us to analyze extremely small areas of carbonates and phosphates (on the order of 10 micrometers) in situ; that is, without having to crush and reprecipitate them. The method

allows for finer spot analysis than had been possible previously with traditional methods that required the homogenization of large amounts of material. The major advantages of this technique are that it is essentially nondestructive and requires little sample preparation.

With the laser ablation method, we're able to not only tell what isotopes a fossil organism was absorbing from its food, but also get a pretty good idea what sorts of food it was eating over its life, because we can look at the actual wear patterns on its tooth enamel and correlate them with the isotope evidence over time and geography.

Doing this with the teeth of a P. robustus sample from Swartkrans, South Africa, Sponheimer et. al. reached a surprising conclusion (emphasis mine):

laser ablation stable isotope analysis reveals that the d13C values of Paranthropus robustus individuals often changed seasonally and interannually. These data suggest that Paranthropus was not a dietary specialist and that by about 1.8 million years ago, savanna-based foods such as grasses or sedges or animals eating these foods made up an important but highly variable part of its diet.

They elaborated on the then-common idea that this species' extinction had been due to its presumed specialized diet (emphasis mine):

A dental microwear study of the earlier (3.0 to 3.7 Ma) hominin Australopithecus afarensis found no evidence that its diet changed over time or in different habitats (20). In contrast, stable carbon isotope (3, 4) and dental microwear texture analyses (1) of the slightly younger (~3.0 to ~2.4 Ma) hominin A. africanus demonstrated that its diet was far more variable. This suggests the possibility that a major increase in hominin dietary breadth was broadly coincident with the onset of increasing African continental aridity and seasonality after 3 Ma (21, 22) and only shortly antedated the first probable members of the genera Homo and Paranthropus (23–25) and the earliest stone tools (26). The undoubted toolmaker Homo is thought to have been a dietary generalist that consumed novel foods such as large ungulate meat and tubers that are abundant in savanna environments (27–30). Paranthropus, in contrast, with its extremely large and flat cheek teeth, thick enamel, robust mandible, and heavily buttressed facial architecture, is often portrayed as a dietary specialist (27–29). Further, it has been argued that this specialization contributed to its extinction when confronted with increasingly dry and seasonal environments later in the Pleistocene, whereas Homo’s generalist adaptation was crucial for its success (28, 29). Our results suggest that Paranthropus had an extremely flexible diet, which may indicate that its derived masticatory morphology signals an increase, rather than a decrease, in its potential foods. Thus, other biological, social, or cultural differences may be needed to explain the different fates of Homo and Paranthropus (31).

In other words, their evidence suggested that both Paranthropus and Homo had inherited an omnivorous habit from their shared australopithecine ancestor. And further, that P. robustus' "specialized" teeth and jaws reflected not a restriction of its eating abilities, but an expansion of it.

This paper strengthened and confirmed a conclusion reached two years earlier by Wood & Strait:

We suggest that although the masticatory features of Paranthropus are most likely adaptations for consuming hard or gritty foods, they had the effect of broadening, not narrowing, the range of food items consumed. It is possible that these adaptations allowed Paranthropus to become a “seasonal specialist” by exploiting previously unavailable fallback food items during periods of dietary stress (Conklin-Brittain et al., 1988). One of us (e.g., Wood and Ellis, 1986), and many others, have wrongly interpreted the derived morphology of the masticatory system of Paranthropus as evidence for stenophagy. Instead, the vast majority of the evidence suggests that the masticatory system of Paranthropus is more consistent with euryphagy. Thus, the extinction of Paranthropus species should not be considered a straightforward consequence of having an overspecialized diet.

Both papers have been cited fairly robustly (if you'll pardon the pun), and when I ask around among my anthro friends, it seems that this interpretation is shaping up to be the standard view of Paranthropus robustus.

What happened here is simple: whoever manowar40's been getting his paleo information from is behind the learning curve. That's not mano's fault, and it doesn't quite add up to an Idiotic Omnivore Claim because it's not exactly a claim that's detached from reality.

It just shows that scientists need to do a better job of communicating their work to the general public.

Rat Race Or Living Space: What Really Drives Evolution?

2011-08-26T15:06:00.000-07:00

Everyone (even Darwin) knows evolution is all about competition. And everyone (even Darwin) might be wrong, at least when it comes to land animals.

That's the conclusion reached in a paper published last year in Biology Letters: Links between global taxonomic diversity, ecological diversity and the expansion of vertebrates on land.

The authors conclude:

The data support the growing evidence that, except following mass extinctions, tetrapod diversity was primarily achieved by unrestricted expansion into empty ecospace, that is by the filling of unrealized modes of life, and multiplying into already realized modes. As taxonomic diversity has increased, there have been incentives for tetrapods to move into new modes of life, where initially resources may seem unlimited, there are few competitors and possible refuge from danger. And as ecological diversity increases, taxa diversify from their ancestors at a much greater rate among faunas with more superior, innovative or more flexible adaptations.

In laymen's terms, they're saying that evolution is driven not by competition, but by the lack thereof, when species escape direct competition by moving into new, unoccupied niches.

The dearth of evidence supporting large-scale biotic replacements driven by competition is nothing new; as the paper notes, Stephen Jay Gould noticed this back in1980, and he wasn't alone. And it's long been understood that when selection pressures are eased (say, by moving to another ecospace), all species will over-reproduce (which probably increases adaptive opportunities). What's new here is the bold claim that this expansion of opportunities, rather than the constraint of competition over resources, appears to be a prime mover of tetrapod evolution.

The paper has since been cited only six times on Google Scholar, including in one paper published just today. So, it's still too early to tell whether its assessment will have a major impact in our understanding of evolution. But the hypothesis instantly appealed to me, so I am going to keep an eye on it.

Reading it, my first thought was that someone ought to test the hypothesis by applying it to hominin evolution, and see whether the diversification of australopiths and their descendents in the Plio-Pleistocene follows the same pattern. That's when hominins moved out of the forests and onto savannah and woodland biomes... niches that had no prior hominoid primate presence. If it held up at this smaller scale, the hypothesis would receive some firmer experimental support, and also potentially shed some light on just what it was, precisely, driving the rapid hominin evolution of this time period.

That question, in case you didn't know, is the big mystery of human evolution, particularly the evolution of our freakishly large brains. Could our big brain be a consequence of the sudden expansion of hominin eco-space, a brain born out of opportunity rather than struggle? It's certainly romantic to think so. But romance won't cut it in science.

As far as I can tell, no one has run such a test yet. I'd like it to be me, but I currently lack the resources and full training to do it properly. I'll just have to keep my eyes peeled and hope that no one gets to it before I do.

A Reason To Get Out Of Bed

2011-08-21T12:24:00.000-07:00

Lila

And then, there is good news, too. But this time on a personal scale.

"We are happy to inform you that Rocco was recently placed in a safe, loving and permanent adoptive home. We know that you will miss him as we do, but hope it makes you happy knowing that his adoption opens our doors to one more suffering animal who desperately needs refuge."

That's good news I received in the mail yesterday about my pet dinosaur, previously of Animal Acres Farm Animal Sanctuary in Acton, CA, a piece of paradise if ever there was one. My sponsorship donation is now being used to pay for the care and upkeep of another lovely theropod, Lila, who was rescued in 2008 after being abandoned at a factory farm.

Go to their site and become a member today. Or do the same at a farm sanctuary near you. It's one of the most immediate and intimate things you can do to help an individual farm animal, and most such sanctuaries will allow you to visit with and get to know your new friend.

I got to meet Lila last weekend, and I'm glad I made the drive. Although at the time, I hadn't gotten the above mail yet, and so was a little distressed that I was unable to find Rocco. I'm glad to hear that he is safe and loved, and that I got to meet Lila. I hope she will find some happiness, too.

Gator Power: Meaner Than A Gator

2011-08-21T12:08:00.000-07:00

File this one under "can doesn't mean should": Alligator fat could be used to make biodiesel.

The shocking thing to me was the sheer size of the alligator meat industry: it "disposes of" 15 million pounds (!!!) of alligator fat in landfills every year. That seems to be separate from the gator skin industry, though I could be wrong. Gators are already victims of factory farming for their skins:

Other “exotic” animals, such as alligators, are factory-farmed for their skins and meat. Young alligators are often kept in tanks above ground, while bigger animals live in pools half-sunken into concrete slabs.(5) According to Florida’s regulations, as many as 350 6-foot alligators can legally inhabit a space the size of a typical family home.(6) One Georgia farmer had 10,000 alligators living in four buildings, where, according to the Los Angeles Times, “hundreds and hundreds of alligators fill every inch of [each] room.”(7) Although alligators can live up to 60 years, farmed alligators are usually butchered before the age of 2, as soon as they reach 4 to 6 feet in length.(8,9) Humane treatment is not a priority for those who poach and hunt animals to obtain their skin or for those who transform skin into leather. Alligators on farms may be beaten to death with hammers and axes, sometimes remaining conscious and in agony for up to two hours after they are skinned.(10)

The last thing they need is a discovery like this to provide an incentive to escalate cruelty to alligators.

Some days, I just don't want to get out of bed.

Rewinding Evolution At Chickens' Expense; And A New Living Fossil

2011-08-19T10:18:00.000-07:00

Here's what was at the top of my Google alert this morning: Scientists altered DNA to create snouted chicken.

Exciting, troubling and totally amazing all at once, if true. Although the scientists didn't alter the DNA at all; they simply altered the development of the DNA in the egg. People -- including, apparently, intrepid science reporters at MSN News -- misuderstand what DNA is and what it does, and so we end up with sloppy phrasing like this headline and some of the sentences in the article itself.

All that happened here is that the team counteracted the development of one molecule and activated another -- both of them already present on the DNA strand -- by adding a protein to the embryonic environment. The chicken DNA remains unchanged, and it is only the expression of that DNA that gets altered.

This isn't genetic engineering, where scientists splice DNA from two different species together to produce a new one. No one imposed alien DNA on these chicken embryos to produce maniraptoran traits. They simply verified the hypothesis that chickens -- and all other birds -- are, in fact, dinosaurs.

Now, I'm not opposed to genetic research, or even genetic engineering per se; like any other tool, it will have both positive and negative consequences. Our job as activists and citizens is to monitor that tool, minimize the negatives and allow the positives to flourish.

Having said that, though, and as neat a trick as the paleontologist side of me thinks this is, it's just that... a trick. It hasn't really told us anything we didn't already know, and strikes me, on the whole, as frivolous at best, cruel at worst.

But, in less-invasive paleo news this week, we've discovered a new/old "living fossil" eel in the Pacific, a primitive taxon now dubbed Protoanguilla palau. I have to say, the deeper into evolution I get, the more I am loving "fish." For the past few months, I've been seriously considering an effort to forge a future for myself in fish paleontology. Fish are such deeply misunderstood and underestimated creatures among the general public that it's difficult to convince people that we shouldn't exploit and eat them, either.

But then, you already know fishing hurts.

More On Miocene "Apes"

2011-08-14T18:44:00.001-07:00

It's not that I don't trust you. I know I included a link in my last post to an article about a time when Earth really was the Planet of the Apes. And I hope you read it. But I still can't stop thinking about it. For about the third or fourth time in my life, I've started going ape for the Miocene apes.

Of course, "apes" don't really exist. That's an old, pre-cladistic term that we paleo students and professionals call a paraphyletic taxon, because it usually excludes the direct human lineage, who sprouted from the same common ancestor. A more proper term would be "Miocene hominoids," but let's face it, when's the last time you called that boorish meat-head who's always trying to muscle you out of the way and steal your mate a "big dumb hominoid"?

It'll never catch on.

So, apes it is. You might think you know what "ape" means, so I'll get back to that in a sec. First, let's talk about this word "Miocene."

As mentioned in my post about giraffes, the Miocene Epoch was a time of great tectonic, climatic and ecological change that proved a crucible of evolution for many lineages. At its start, about 23.8 Ma, the non-avian dinosaurs had already been extinct for 42 million years. Avian dinosaurs (aka, birds) and mammals flourished in their absence, expanding into all terrestrial niches. Mammals had returned to the sea, and were starting to develop their special brand of echolocation (like "apes," cetaceans reached the period of their greatest diversity during the Miocene). Grasses and kelps were radiating into new regions, while the planet's tectonic plates were coming close to their current positions (although South America and North America were not yet connected, and India was only beginning to collide with Eurasia). The uplift of the Andes and Himalayas mountains and the closing off of the Tethys Ocean slowly but radically altered Earth's climate, so that by the end of the Miocene, many animals had been forced to migrate to mid-latitudes as the world got colder.

At the start of the Miocene, monkeys were the biggest game in town among the primates. At the end, they had been supplanted by the apes, who had already begun to evolve into our direct ancestors.

When I was a kid, I used to call the Miocene "the Age of Apes," to make it sound equal to the "Age of Dinosaurs." Mostly, that was human bias talking, but there's still some justification for the name (provided you pay no never-mind to those cetaceans and grasses staking their claims): apes reached the height of their diversity in the Miocene, radiating across Eurasia and Africa into nearly 100 different species. Sadly, most of them went extinct as the Miocene climate got steadily colder, and the survivors fled to Africa and southern Asia, where they became gorillas-chimps-humans and gibbons, siamangs and orangutans, respectively.

When most people think of an ape, they imagine either a knuckle-walker like the gorilla and chimp, or a tree-swinger like the gibbon and orangutan; but the apes of the Miocene were more diverse than that. They had mastered just about every form of terrestrial locomotion except flight and bipedalism... and we're not sure about bipedalism.

But I'm putting the monkey ahead of the banana here.

What's In An Ape?

It's common to use the words "monkey" and "ape" interchangeably, but this isn't quite accurate. Apes diverged from a monkey-like common ancestor a long time ago, most likely before the Miocene began, and there are numerous anatomical differences between them. Notably, apes have no tails and larger brains in relation to body size than monkeys do. Their arms are longer and, along with their hands, more flexible than those of monkeys. Some people get confused here, though, because when you look a little more closely, you find that apes have many things in common with some monkeys, but not others. Usually, the monkeys who share traits with apes are called "Old World" monkeys (because they're found in Africa and Eurasia), and the ones who don't are called "New World" monkeys (guess where they come from?).

Apes share a common ancestor with Old World monkeys, and together with them make up a group of primates called the Catarrhines, who are characterized by their downward facing nostrils and tails used for balancing rather than grabbing. New World monkeys form a group called the Platyrrhines, or flat-nosed monkeys.

The lines of the Catarrhines and Platyrrhines diverged from each other about 40 million years ago, when a group of Platyrrhine ancestors somehow made it across the Atlantic Ocean to South America, in one of paleontology's biggest mysteries. We're still nowhere close to figuring out how that happened.

So, apes are monkeys, sort of, because they are Catarrhines and display most of the Catarrhine characters. Except that "monkeys" aren't really monkeys, since there are two independent lineages who diverged from some common ancestor that wasn't quite a monkey, either.

Got that? Good, because there will be a quiz.

The main point I'm working up to here is that most people today, if pressed to describe how an ape moves, would say either, "walking on their hands and feet" or "swinging from trees." Those of more precise observatory skills would point out that ground-walking apes specifically walk on their knuckles rather than their palms, and tree-dwelling apes get around by hanging and swinging below branches rather than on top of them. These methods are distinct ways of movement among living apes, so there's a temptation to define the group "apes" by them.

But just as, paleontologically, giraffes are not defined by their long necks, "apes" aren't defined by these ways of moving. And for the same reasons: most of their ancestors didn't do it that way.

The earliest true "ape" (whom you met in my hokey screenplay spoof) was Proconsul africanus, a hominoid who lived between 25 and 15 Ma in the forests of east Africa, but had cousins all over Eurasia, as well. If you saw a Proconsul today, you'd probably think it was a giant tailless monkey, because like monkeys, it walked with its body parallel to the branches (rather than swinging perpendicularly below them like gibbons and orangs) and walked on its palms (instead of its knuckles like chimps and gorillas). The technical term for this is "pronograde arboreal quadrupedality."

P. africanus retained several monkey-like features, such as thin tooth enamel, a narrow torso and relatively short arms. But its brain was larger than those of monkeys relative to body size, and it lacked a tail. Since Catarrhines used their tails for balance, their hominoid descendants had to find a way to compensate for this ability upon losing their tails. That's where their hands and feet come in.

Proconsul's hands and feet are distinct from those of monkeys in that their first rays are well-developed and their phalanges are elongated. In layman's terms, Proconsul had more flexible wrists, ankles, fingers and toes than other Catarrhines, and used them rather than a tail to balance themselves.

P. africanus and the other members of its genus represent the basal-most "ape" body plan, the foundation from which subsequent species evolved increasingly diversified and specialized forms of locomotion, including the knuckle-walking of chimps and gorillas, the tree-swinging of gibbons and orangs, and the obligate bipedality of humans.

Understanding this point about Miocene hominoid locomotion is important, because a lot of people tend to think that evolution stood still for apes while it marched onward for humans. They imagine that our common ancestor with, say, chimps was basically a chimp. But chimps have been diverging from the common ancestor for 6 to 7 million years, just like we have. Unfortunately, the fossil record of chimp evolution is currently poor, but it's likely to contain as many extinct intermediaries as the human one does, possibly even with as much diversity.

The same is true for all other apes, extant and extinct. Various traits of the still-living hominoids -- including precision grasping and a possible form of bipedalism -- all have their precursors among the Miocene apes, who added in many other locomotive and dietary specialties no longer found among the living "great apes."

Since this post is getting a bit long for my preferences, I'll end it here. But this won't be the last you hear of the Miocene apes. I'll do future posts on many of them individually.

Meanwhile, please do not neglect the ape protection and rescue links I provided in my previous post. If no other animals deserve "rights," the apes most certainly do.

Rise Of The Planet Of The Apes: Been There, Done That

2011-08-13T02:18:00.000-07:00

Look, Hollywood, I get it, OK? I understand you've got to get butts in seats, and so feel the need to erect -- or resurrect -- franchise tent-poles every year. But would a little originality now and then be too much to ask?

I mean, c'mon: apes rising up to conquer the world? What a bunch of hackneyed Miocene tripe!
-----------------------------------------------------------
FADE IN:

EXT. EUROPEAN RAIN FOREST, 19 MILLION YEARS AGO - DAY

An idyllic jungle scene, erupting with the full spectrum of the rainbow, something out of a Disney movie. Animal calls abound. Familiar-looking, colorful birds flutter about among gorgeous flowers and bright green leaves. The wind rolls through and rustles the foliage aside, revealing a huge cluster of STRANGE, BRIGHTLY-COLORED FRUIT, hanging succulently from the branches, making our mouths water.

We're not alone in that reaction.

Suddenly, we hear a chorus of joyful HOOTS and GRUNTS, presaging the arrival of a band of CATARRHINE MONKEYS, who scamper elatedly across branch-tops, driving away the roosting birds.

There's an arrogance to these almost-familiar monkeys, with their downward-facing nostrils and tails used for balance rather than grasping. They've ruled the primate world for millions of years, and they know it. They want the fruit, and there is no one to stop them.

Except each other. A fight breaks out when it becomes clear there isn't enough fruit to go around. Rocks and bark are thrown. Teeth are bared in screeching contests. Loose leaves rain down from the canopy as the treetops shake from the monkey fight. And finally, there is a victor.

One relatively big male -- we'll call him HANUMAN -- wins the day, with the help of his betas. They form a defensive ring around the fruit, holding off the other bands of monkeys. Their females, some with babies clinging to their fur, come out of hiding, to groom the males and share in the spoils of war.

HANUMAN perches on a high, sturdy branch, as though he's about to give a speech. The others look on with admiration, especially the younger males who envy his position and access to mates.

Though he speaks in hoots and grunts, we can still understand him.

HANUMAN

Brothers, friends, wives, lend me your ears. You fought well, and deserve these sweet treats. But we must conserve our strength.

BRASH YOUNG MALE

Finally ready to give up some wives, eh, old man?

The other males let forth with hearty monkey-laughs.

HANUMAN

No, young one. I'm as strong as ever. But if we are not careful, we will all have to give up more than wives. Maybe everything.

This gets everyone's attention.

HANUMAN

There's a new creature in our forests. A giant who has come from far away to take our fruits and our bugs and our trees. And he is not alone.

BRASH YOUNG MALE

Bah! More fear-mongering from an old tyrant. Have you seen these giants, Hanuman?

HANUMAN cuffs the BRASH YOUNG MALE, silencing him.

HANUMAN

No, but others have. It is said they walk like monkeys, but they have no tails. And their arms are too long. And their faces... I am not ashamed to admit, brothers, that I am concerned. Long we have ruled these forests, but I fear our days are ending.

BRASH YOUNG MALE

(now out of cuffing range)

Phish! I'll believe it when I see it, old fool.

Other young males hoot their agreement. HANUMAN scowls, ready for a challenge from the BRASH YOUNG MALE, who's puffing his chest and baring his teeth, posturing for a fight.

They circle each other, male and female monkeys alike making room on all sides. But just as they are about to pounce, something in the air changes.

Everyone senses it, and freezes in their tracks. The hooting stops, so they can all be sure they hear it.

Over there! And there! All around them, it's coming through the trees. Something big. And it is not alone.

The monkeys forget their quarrel, and pull in close to one another, HANUMAN and BRASH YOUNG MALE now united in common defense of their band. They all take slow steps back, until they're pressed against each other and can go no farther.

That's when it comes out of the forest, slow, confident, arrogant as a monkey and twice as cunning. It does not need to push aside the leaves and branches; instead, they simply seem to flow around him.

After a beat, others like him follow. They have the monkeys surrounded.

These new creatures look half-monkey, half-something-else. They walk on the branch-tops, using the palms of their hands and the soles of their feet, like monkeys do. Their hips move in monkey-like fashion, too, but are more flexible.

And there are differences that set them dramatically apart. First, and most obviously, they have no tails, and this accounts for the strange grace of their movements. Their bodies achieve balance in the treetops through other, more subtle structures. Their arms are too long. Their hands and shoulders seem more pliable, with greater ranges of movement. And their faces, too, are all off-kilter compared to the monkeys, in subdued and awful ways.

Alone, these differences would not stand out. But taken together, they make something completely new, and completely alien to the Miocene world.

These are the first apes.

Their leader, an old and powerful-looking gray-hair, steps forward with the self-assurance of a natural ruler. We'll never know his real name, but one day we'll call him, and his people, PROCONSUL.

PROCONSUL

We have not come to fight, friend monkeys, but be assured, we will if we must. I know we look strange to you, but we are brothers nonetheless.

HANUMAN

Then why do you steal our food, brother?

PROCONSUL

Steal? The food is ours. As is the land, though we come from far away. We are the first of our kind, but we will not be the last.

HANUMAN puts up a good show, enough to save face with the monkeys. But PROCONSUL cuffs him, and it's clear this fight is over before it started. The monkeys all hang their heads in shame... all except HANUMAN, who nonetheless looks away.

PROCONSUL

There is no shame in standing aside. You have been good stewards of the land, but your time has passed. That is the way of things. Just as you assumed the mantle from the tarsiers, now we assume it from you. The age of monkeys is at an end. The world now belongs us.

At a gesture from PROCONSUL, the apes make room and let the monkeys pass. One by one they leave, mourning the end of their supremacy, fading into the background of the jungle.

HANUMAN is the last to go. He dares one last moment of eye contact, and hands PROCONSUL the juicy FRUIT he'd been defending.

PROCONSUL nods his thanks, and lets the King of the Monkeys go to his people.

When the monkeys have gone, PROCONSUL looks to his fellow apes and smiles. They all hoot and screech triumphantly as he hands out the fruit.

Truly, it is a new world...
------------------------------------------------------
So, you've probably figured out by now that this isn't a review of the new James Franco vehicle in which uplifted and put-upon apes launch a revolution by attacking humans during rush hour (at our most vulnerable!).

And I'm not going to post any such review. I'm not even sure I'm going to see the movie, at least in a theater. But I will confess to being perversely interested in it, for two reasons.

1) It looks like it has an anti-vivisection message (though it'll probably be of the typical, reactionary Hollywood science-phobic variety, and not one that makes people think about the ethics of animal experimentation); and,

2) It's gotten me fired up about an old paleo-passion of mine: the Miocene apes, who dominated Eurasia for millions of years, radiating into possibly 100 different species in 40 genera, including the lineage who eventually migrated back into Africa and became us. This was the real "rise of the planet of the apes," and it's one of the most fascinating periods of mammalian evolution, to boot (don't let the corny screenplay above dissuade you).

So, in a shameless attempt to capitalize on Google searches for the movie's title, here are some great links about both subjects.

Learn about the true Planet Of The Apes. Way cooler than the movies.

And then, stick your neck out and do something to help preserve the apes we still have left.

Officially-Stolen PaleoVegan Theme Song

2011-08-12T18:03:00.000-07:00

I haven't the words.

Idiotic Omnivore Claims

2011-08-05T23:35:00.000-07:00

Yes, it's not just (some) vegans who wear their ignorance of biology and evolution like a badge of honor. Turns out, paleos can also drink from the Well of Evo-Woo. Try to contain your shock.

See, seems there's a meme floating around in some omnivore circles that personifies the title of this post: namely, that human production of hydrochloric acid in the stomach is proof that we are "meant" to eat meat, because herbivores don't produce HCl in their stomachs.

I've encountered it three times in online comments sections; once at Let Them Eat Meat; once at The Huffington Post; and most recently on the comments of a YouTube video featuring Jonathan Safran Foer. I've stopped counting the number of times I've heard it from meaty-mouths here in meatspace.

But, I did start to wonder where this embarrassingly moronic claim originated. So, I've been trawling the depths of Google and Bing on my quest to find out, and I think I nailed it down.

From what I can tell, the meme got its start with The Myths Of Vegetarianism by Dr. Stephen Byrnes. Check out paragraph 2 of his Myth #11:

Some vegetarian groups claim that since humans possess grinding teeth like herbivorous animals and longer intestines than carnivorous animals, this proves the human body is better suited for vegetarianism (123). This argument fails to note several human physiological features which clearly indicate a design for animal product consumption.

First and foremost is our stomach's production of hydrochloric acid, something not found in herbivores. HCL activates protein-splitting enzymes. Further, the human pancreas manufactures a full range of digestive enzymes to handle a wide variety of foods, both animal and vegetable.

Further, Dr. Walter Voegtlin's in-depth comparison of the human digestive system with that of the dog, a carnivore, and a sheep, a herbivore, clearly shows that we are closer in anatomy to the carnivorous dog than the herbivorous sheep. (124)

I don't know much about Byrnes; he's described as a naturopathic doctor (warning klaxon #1), recommended the Weston Price Foundation (klaxon #2... and no, I will not link), and apparently did good work for HIV/AIDS patients in Hawaii (genuine applause) before dying suddenly of a stroke in 2004. Nor do I know where Byrnes came up with this silly idea about herbivore digestion. But since the encounters I've had with this meme have all been worded almost exactly like the emphasized paragraph above, I think I can safely blame Byrnes for giving this one legs.

He should have known better, and shame on him for starting it. More shame on those in "paleo" circles who should also know better and should have corrected him on this point long ago. I mean, they wouldn't want to embarrass themselves and their cause by spouting provably false information and then getting publicly called on it, would they?

Like suffering and empathy, gastric secretion of HCl is conserved in all vertebrates. Without knowing which specific digestive enzymes Byrnes was referring to (though I suspect it's elastase, which I've heard more than one carnist apologist invoke), I can still safely predict that the same is true for his pancreas claim, as well.

To put it plainly: yes, herbivores do produce hydrochloric acid in their stomachs. So do carnivores and omnivores. There's nothing particularly noteworthy about it; it's just part of all vertebrates' fishy ancestry.

The fact Byrnes was pointing to, without seeming to realize it, is that carnivores and herbivores produce differing amounts of HCl, reflecting their different trophic strategies. Hominins fall here, as in most other ways, somewhere in the middle range, making them generalists or "omnivores." Which is a perfectly valid point to make when arguing against the "man-is-a-natural-vegan" claim; it's too bad a guy with a Dr. in front of his name didn't possess enough of a grasp on basic biology to spot such a simple error, and thus lured himself and his readers into looking like bozos. But then, that's what you get for credential-mongering.

Fact-checking: it's the science-y thing to do, friend paleos. Given your self-chosen moniker, you guys really ought to be more careful. Call this one a gift.

NOTE: I'm not planning on Idiotic Omnivore Claims becoming a regular feature at PaleoVeganology, but I will keep my peepers peeled nonetheless.

Sorry, Archie; There's An Earlier Bird Getting Your Worm

2011-07-30T17:13:00.000-07:00

Add this to the ever-growing list of things Darwin and Huxley might have been wrong about: Archaeopteryx wasn't a bird, after all! Or was it?

The bird-dinosaur link is perennially confusing to people, sometimes even to me. Cladistically speaking, birds are dinosaurs, literally. They never stopped being dinos, any more than humans stopped being primates. The debate here isn't whether Archeaopteryx was an early bird, but whether it was an avian or a non-avian dinosaur.

But, the zeitgeist, even among paleontologists, continues to demand that we think of animals in discrete categories (or "kinds," as creationists like to put it). This, in turn, leads to "missing link" quests that promise only to cloud rather than clarify public understanding.

The editors at Nature's press release office should know better than to frame the discovery this way. But, it's what gets headlines, so I can't really hold it against them.

Book Review: "The Animal Connection" By Pat Shipman

2011-07-30T16:23:00.000-07:00

Such a wonderful read, and a much-needed demonstration of the folly of ignoring the obvious. Here's a book that looks at the culturally universal phenomenon of human cross-species emotional connection through the lens of evolutionary theory and asks, "how did this behavior arise? What selective benefit did it give early hominins to adopt members of other species into their own tribes and families?"

And it's no mushy cute-fest, either, let alone a sentimental appeal for us to love animals. Instead of saying we should love nonhumans, Shipman begins with the observation that we already do, and works from there. What may be the book's greatest failing from an ideological animal-liberation perspective -- Shipman draws no ethical conclusions from her observations, and mentions the movement only peripherally as one modern expression among many of an ancient human trait -- is probably its greatest strength as a work of popular science literature. It will hold its greatest appeal for average dog- and cat-lovers inclined to ponder their love for their pets from an evolutionary perspective, and steers scrupulously clear of any sort of animal advocacy. But that's no reason not to read it.

Shipman states her hypothesis clearly right from the start:

I believe that a defining trait of the human species has been a connection with animals that has intensified in importance since at least the onset of stone toolmaking 2.6 million years ago. Defining traits are what makes humans human, what makes us different from all other animals, and they are partially or wholly encoded in our genes. I don't claim that the animal connection is the only defining trait ... but I do claim that our connection to animals is so deep, so old and so fundamental that you really can't understand human evolution and nature without taking it into account.

Shipman contends that at each of the "big three" advances in human behavioral evolution -- toolmaking; language and symbolic behavior; and domestication of other species -- an ability to form empathic bonds with nonhuman animals played a crucial, if not determinative, role. From there she embarks from the beginning of human evolution and works her way up to modern times, laying out her evidence at the three big shifts in an impressively comprehensive approach.

Obviously, I'm not going to list all her evidence here -- after all, this book is well worth reading in its entirety, and I'm certainly not going to make it easy for you to crib. But I will say that of all the "big three" shifts, I think her evidence for the animal connection's role in the spread of language and symbolic behavior is the weakest. Her argument on this point is both persuasive and parsimonious, but the direct evidence of it in the book is sparse. Nonetheless, as a whole the book is brilliant, rigorous, and at times even moving.

It's also one of the most scientifically-accurate popular explanations of human evolution that I've read in about 10 years. That alone is worth the price of admission.

The book was moving and useful to me because it helped me make some evolutionary sense of my life-long feelings of empathy for animals, my veganism and my animal advocacy. I don't need to tell you any of the silly, hurtful things I've had strangers and loved ones say to me about my "unnatural" lack of species loyalty; I'm sure you've heard many of the same crude remarks yourself.

But if you're like me, you've always known that your sense of connection to nonhumans was a deep-seated, unchosen part of who you are. It has always felt like the most natural thing in the world to you, as much a part of your make-up as your love for family or country. To you, as to me, these other animals have always felt like part of the tribe, and it was a mystery to you why other humans wouldn't agree.

Shipman argues that this is an expression of an ancient, and probably partially genetic, impulse in H. sapiens. Nature, she claims, has selected for cross-species empathy in hominins. In the early days, it was useful to our ancestors in acquiring animals for food and resources; hominins who understood animal thought and behavior were more successful than those who weren't. And nature intensified this trait as more hominins found more uses for it over millions of years. But as with most inherited traits, the animal connection lends itself to more than one expression. And so, we now live in a world where people lavish pets with billions of dollars in consumer spending, identify tribally with animal-totem athletic teams or cartoon characters, continue to visit zoos and circuses even in economically-depressed times, and -- in one little corner over here -- agitate earnestly for the liberation of nonhumans from exploitation.

It's all, Shipman argues, perfectly natural, and all characteristically human. We all express the animal connection in different ways, but it's still there, almost everywhere you look in human culture and history.

There are no statements of animal advocacy in Shipman's book, but she has done the animal liberation movement a great service in writing it. She acknowledges as an empirical fact what we have always known, and often waste a great deal of wind trying to convince speciesists of -- that empathy for nonhuman animals is one of the most human things there is. It does not require any more intellectual justification than possessing vertebrae or walking upright. It's simply a given of human nature.

This is what I meant earlier when I mentioned "the folly of ignoring the obvious." We ignore the obvious connection between human and nonhuman every time we try to convince speciesists of its existence; or rather, we become complicit in and indulge their often-willful ignorance of the connection. Do we waste time trying to convince people that it's natural to breathe? Well, we shouldn't waste our time convincing them it's natural to care about animals, either. It wastes our time, and the animals' time, too... time that animals don't have.

By using the obviousness of the animal connection's existence as her starting point, Shipman has, whether she knows it or not, advanced the debate about animals by leaps and bounds, and helped ground animal liberation ethics in a evolutionary view of life... and moreso than any actual animal-lib thinker who comes readily to my mind. This is a book I'll return to time and again.

Informing Our Ethics With Evolution

2011-07-11T21:35:00.000-07:00

Let's face it, the implication of this blog's name is kind of cheeky. Despite my disclaimers, it still implies that there's a necessary connection between "paleo"-something and veganism. Maybe, if I had it to do over again, I'd call the blog "Evolvegan" instead, because that's closer to what I think I was driving at.

There's always been an insight floating around nebulously in my subconscious about what the study of evolution can say about animal liberation and ethical veganism. But until recently, I hadn't been able to put it in words. I left that, inadvertently, to someone else.

Someone I've exchanged a few emails with wrote a sentence that set off alarms and ignited light bulbs in my head. As soon as I read it, I thought, "Yes! Yes, that's it, exactly!" It was like my pesky camera finally snapped into focus after months of my fiddling ineffectually with it. The sentence was simple, elegant, and immediately clear to anyone who truly understands evolution:

Suffering is conserved in all vertebrates.

That's the foundational insight of this blog, boiled down to bare essentials (thanks, D, for saying it so beautifully; I hope you don't mind my borrowing it). The only thing I'd add to it is:

And so is empathy.

These two emotions -- empathy and suffering -- exist in all vertebrate animals. If they didn't, there's no way they'd exist in humans. We inherited our capacities for empathy and suffering from a long line of common ancestors, as Darwin hinted at in both The Descent of Man and The Expression of Emotions in Man and Animals. Work since Darwin has only confirmed and expanded this insight.

It shouldn't surprise us, really. It should be obvious. But to a lot of people clinging to the specialness of their humanity, it's not obvious at all (speciesism is probably an inherited trait, too!). In fact, a lot of people expend their energy and bandwidth justifying their speciesism by appealing to evolution, accusing ethical vegans of not "getting it." They imply there's something un-natural about our advocacy.

But there isn't. Empathy and suffering are both conserved in vertebrates. When we act upon those two traits and seek animal liberation, we are grounded in our evolutionary kinship with other species. We have taken the fact of common descent to its fullest ethical conclusion. Others may have different interpretations of the evidence, but that does not make their interpretation any more "natural" than ours.

It is perfectly natural to feel another being's pain, and to desire an end to their suffering. It's also natural to act on those feelings, and build an ethic around them. Attaching a "paleo" to the "vegan" is simply a proclamation of this kinship-by-common-descent.

We will not exploit, enslave or eat our kin.

Oh, and what about invertebrates? Do they suffer, too? Honestly, I'm not sure, but it costs me nothing to give them the benefit of the doubt. So, I won't eat them, either.

Quite A Stretch, Mr. Darwin: Adaptation, Diet and the Giraffe's Short Neck

2011-07-04T19:28:00.000-07:00

In studying evolution, the answer to any given puzzle is rarely obvious, even when we think it is.

Take the giraffe's long neck. This one seems like a no-brainer: giraffes evolved long necks in response to food scarcity and competition with other browsing mammals. Having a slightly longer neck enabled the giraffe's ancestors to reach slightly higher browse than other mammals, and over millions of years, the trait was inherited and enhanced by natural selection, producing the majestic, iconic animal we see today.

Or so you were probably taught. Just like me. It makes perfect, logical sense; intuitively, it feels right. Darwin himself made the same speculation in the sixth edition of On The Origin Of Species:

So under nature with the nascent giraffe, the individuals which were the highest browsers and were able during dearths to reach even an inch or two above the others, will often have been preserved; for they will have roamed over the whole country in search of food. That the individuals of the same species often differ slightly in the relative lengths of all their parts may be seen in many works of natural history, in which careful measurements are given. These slight proportional differences, due to the laws of growth and variation, are not of the slightest use or importance to most species. But it will have been otherwise with the nascent giraffe, considering its probable habits of life; for those individuals which had some one part or several parts of their bodies rather more elongated than usual, would generally have survived. These will have intercrossed and left offspring, either inheriting the same bodily peculiarities, or with a tendency to vary again in the same manner; whilst the individuals, less favoured in the same respects, will have been the most liable to perish.

Darwin's endorsement of this speculation has given it the force of orthodoxy, and this interpretation remains, 150 years later, the textbook example of a straightforward case of natural selection in action.

But it might be completely wrong.

I started thinking about giraffes after my interview at Let Them Eat Meat, in which I pointed out that evolution is more complex than most people realize, and therefore we should be wary of seemingly straightforward connections between food and (assumed) adaptations. What seems like a no-brainer might, on closer inspection, turn out to be a just-so story. As Stephen Jay Gould warned (in his classic essay The Tallest Tale, among many other places) "consequences of substantial import often arise from trivial triggers of entirely different intent. In other words, current utility bears no necessary relationship with historical origin."

In short, at the time of Darwin's writing, and even up to the time of Gould's, there was no body of evidence straightforwardly indicating that giraffes evolved long necks in response to dietary selection pressures. And despite the fact that there's been some excellent giraffe research done since then, there still isn't. The origin of the giraffe's long neck is still an intriguing mystery.

What makes a giraffe?
If you're like most people (and why wouldn't you be?), you're accustomed to defining giraffes by their long necks. It's pretty much their distinctive characteristic in the common imagination. But it turns out that in this case (as in so many others), the common imagination is wrong. Most giraffes throughout Earth history have not had long necks. For that matter, giraffes today don't have long necks, either.

A giraffe struggles against its short neck to get a drink.

Yes, you read that correctly. Giraffes don't actually have long necks!

Just look at the stance they have to assume in order to drink water: legs splayed, forming a triangle with the plane of the ground, stretching their necks to the water's surface... and then still barely able to reach.

Contrast this stance with that of any other terrestrial quadraped; say, the antelope, or the rhino. None of them have to stretch their legs in an awkward angle to take a sip. They just stroll up to the water's edge, bend their necks down, and drink. Their legs are never involved.

Not so with the poor giraffes, for whom every drink involves a yoga stretch. They may be the tallest land animals in the world, and their necks may be the longest among all others in absolute terms, but relative to their ability to get water, giraffes have shorter necks than any of their relatives among the ungulates, and arguably among any other group of terrestrial animals.

So upon closer inspection, it doesn't make much sense to define giraffes as a species based on their supposedly long necks. To figure out what makes a giraffe a giraffe, we have to look more precisely at their morphology and fossil record. What do modern giraffes, Giraffa camelopardalis, have in common with their closest living relatives, Okapia johnstoni? And what trait(s) do these two extant clades of giraffids share with their common ancestors and fossil relatives? What distinct anatomical feature(s) unites the living and extinct giraffids into a coherent taxon?

Okapi: the other giraffe! No long neck here, either...

As you've probably guessed by now, it's not long necks. The giraffid party is all about teeth; specifically, canine teeth. The diagnostic character of giraffid fossils -- that is, the derived trait paleontologists use to tell whether they've found a giraffid fossil or that of some other hoofed beastie -- is bilobed lower canine teeth, which are especially useful for stripping foliage off of browse.

This distinct trait first appears in the fossil record between 10 to 15 million years ago, with the rise of the Climacocerids, of whom the most famous member is the early giraffoid Canthumeryx syrtensis, who looked more like an antelope with horns askew than like what most people think of when they think "giraffe." C. syrtensis was a grazer/browser who lived in the lush flood plain/savannah/river basin habitat of what is now Libya, and had relatives all over North Africa and southern Eurasia, as far east as India.

In addition to being a relative of modern giraffes, C. syrtensis was likely also an ancestor of the sivatheres, a clade of bulky, moose-like giraffids who didn't have "long" anything, as far as we can tell.

Canthumeryx syrtensis

But the first animal with all the traits of a possible direct ancestor of modern giraffes, that also occupies the right geological position, is Giraffokeryx ("giraffe herald") from the Miocene Siwalik deposits of India/Pakistan. The Giraffokeryx looked more like an okapi than a modern giraffe, except that it had four ossicones rather than the two found in extant species.

Giraffokeryx is considered transitional between the canthumerycids and later giraffe relatives, and after it, things start looking a bit more familiar; its ancestors, the palaeotragines (who looked even more like the okapi than Giraffokeryx did), gave rise to the samotheres, who ultimately became the modern giraffe. The resemblance between okapi and basal palaeotragines is so strong that some have argued that the okapi is a "living fossil" representing the morphology of ancestral giraffids, unchanged over millions of years because it occupies a forest niche unchallenged by any other species.

Giraffokeryx

The samotheres replaced most of the other palaeotragines by the Miocene/Pliocene transition (9 to 5 Ma), and were generally larger and longer-faced than their ancestors, looking more and more like modern giraffes as time progressed. It was with this group that the elongation of the neck and legs really began to take off, and the genus Giraffa (which once contained six species, and now only one) was born between 7.1 to 7.3 Ma.

So, Why The Long Neck, Mr. Giraffe?
Fascinating as this evolutionary history is, though, it still begs the question, "why did giraffes evolve long necks?"

But in a very real sense, that's the wrong question to be asking, let alone begging, since it's clear that most giraffes through time didn't have long necks, and relative to their own bodies, modern giraffes arguably don't actually have long necks, either. The real question, then, is, "what made Giraffa species get so much taller overall than their ancestors?" To make anything like an educated guess on that question, we have to look at the world in which giraffes emerged.

Sivatherium

The emergence of "true" giraffes across the Old World and their subsequent retreat into Africa happened against the backdrop of the Miocene/Pliocene transition, a time of enormous climatic, geographic and tectonic change. Starting about 10 Ma, the Himalayas and the Tibetan plateau entered a second phase of uplift and the Paratethys Sea began to slowly dry up and retreat. At the same time, other geologic processes like sea-floor spreading, silicate weathering and sediment burial began to lower atmospheric CO2 concentrations.

All of these factors working in concert fundamentally altered the ecology of central Asia and north Africa, (heck, the rest of the world, too), where Giraffa's ancestors had thrived. The region stretching from western India to northern and eastern Africa went from a tropical rainforest environment dominated by C3 plants to an arid savannah populated by C4 grasses. Deciduous forest biomes gave way to conifers and other small-leafed, arid-adapted plants. Rainfall became more seasonal north of the Himalayas, the Tibetan plateau became drier, and summer and winter monsoons got stronger. South of the Himalayas, summer temperatures and rainfall increased dramatically. Collision of the African and Eurasian tectonic plates caused coastal upwelling of the Arabian Sea and created land bridges between Europe, Asia and Africa, allowing for the migration of giraffids (and other species) into Africa. By 6 Ma, C4 plants dominated central Asia, and the decline of giraffids there began in earnest. Then, between 6 Ma and 2.6 Ma (the Plio-Pleistocene transition), there was further uplift of the Himalayas (throwing monsoonal patterns further out of whack), an expansion of continental ice-sheets, and a prolonged period of global cooling. These factors led to the extinction of Giraffa species in Asia, and the retreat of remaining giraffids into Africa.

It seems likely that these upheavals served as the crucible in which Giraffa developed its incredible suite of adaptations, including its height, but nailing down precisely which of these factors caused which of the giraffe's traits is tricky, if not impossible. In particular, the intuitively-appealing idea that height provided giraffes with a selective advantage over other herbivores becomes murkier upon close inspection.

Palaeotragus primaevus

The first giraffe researcher to raise an objection to this idea was Chapman Pincher, who made the following points in a 1949 Nature article titled "Evolution of the giraffe":

any dearth of resources that was long enough, severe enough and/or frequent enough to produce a selective pressure for long necks would cause a recurring wastage of young giraffes, and thus the extinction of the species; i.e., if young giraffes can't reach the high browse for which they're supposedly adapted until they reach adulthood, then they'll never reach adulthood!;
the same dearths would have produced selection for long necks in other herbivores, yet only giraffes achieved this adaptation; and,
adult male giraffes are, on average, one meter taller than adult females, who are in turn taller than all their young. Thus, dearths would place shorter members of the species at a permanent disadvantage, yet again ensuring extinction of the species.

Against these points, Pincher argued that the neck of the giraffe was only "long" because as their leg length increased, giraffes would need to be able to reach water sources from greater heights. Thus, their neck is just long enough to do the job, and no longer (remember their short necks?).

About 15 years later, A. Brownlee, also in a Nature article entitled "Evolution of the giraffe," agreed with Pincher's objections, but argued that height provided giraffes with improved thermoregulation and a better ability to avoid, detect and fend off predators.

The question of whether height provides a feeding advantage to giraffes is further complicated by the variant feeding patterns of giraffes in different habitats. In South Africa's Kruger National Park, for instance, male giraffes tend to feed at a greater height than females, who in turn feed at a higher level than young. Average feeding height is between 1.7 and 3.7 m, again with males tending to feed higher. This places female and young Kruger Park giraffes in direct competition with kudus, whose feeding height range is between 1 and 2 m.

But in Kenya's Tsavo National Park, giraffes spend about 50 percent of their feeding time browsing below a height of 2 m. And in the Serengeti, they mostly feed on low-growing Grewia bushes.

On balance, then, it appears that, at least in Kruger Park, height provides giraffes with only a marginal feeding advantage. A marginal advantage is certainly good enough for natural selection to work with, but it doesn't explain why giraffes grow to an average height of 5 m when an average feeding height of 3 m would be all that's needed.

Yet another team of giraffe researchers argued that long necks are driven by sexual advantage rather than feeding advantage. Male giraffes frequently use their necks as weapons in defense of females in estrus, as well as in dominance contests with other males. Thus, there would be sexual selection for long necks in males, and female offspring would inherit the trait without really "needing" it.

But then, here we are again (potentially) indulging the adaptationist fallacy that current use is necessarily related to evolutionary origin. It might be that giraffe height has nothing to do with any of these clear adaptive advantages. Or, it might be the product of all of them at the same time. As Darwin noted, "(t)he preservation of each species can rarely be determined by any one advantage, but by the union of all, great and small." Or, it could be a side-effect of pleiotropy.

The bottom line is, we just don't know for sure why giraffes evolved to be so tall. And it'll probably stay that way for a long time. Until it's figured out, we should avoid the temptation to take at their word anyone speaking authoritatively about the importance of specific traits... even Charles Darwin. Truth is, in such situations, they're claiming to know more than they possibly could.

References:

Brownlee, A. 1963. Evolution of the giraffe. Nature 200: 1022.
Du Toit, J.T. 1990. Feeding-height stratification among African browsing ruminants. African Journal of Ecology 28: 55–61.
Leuthold, B.M. & Leuthold, W. Food habits of giraffe in Tsavo National Park, Kenya. East African Wildlife Journal 10: 129–141.
Mitchell G, Skinner JD: On the origin, evolution and phylogeny of giraffes Giraffa camelopardalis. Trans Roy Soc S Afr 2003, 58:51-73.
Pellew, R.A. 1983a. The giraffe and its food resource in the Serengeti. I. Composition, biomass and production of available browse. African Journal of Ecology 21:241-267. 2. Response of the giraffe population to changes in the food supply. African Journal of Ecology 21:269–283.
Pincher, C. 1949. Evolution of the giraffe. Nature 164 (4157): 29–30.
Simmons, R.E. & Altwegg, R. 2010. Necks-for-sex or competing browsers? A critique of ideas on the evolution of giraffe. Journal of Zoology 282: 6-12.
Simmons, R.E. & Scheepers, L. 1996. Winning by a neck: sexual selection in the evolution of giraffe. The American Naturalist 148(5): 771–786.

Richard Dawkins Interviews Peter Singer

2011-06-27T11:31:00.000-07:00

I have to say, I'm rather disappointed with Dawkins in this interview. But at least he has the intellectual integrity to admit that he's just lazy and conformist when it comes to eating meat, and doesn't try to offer an elaborate justification for ignoring the moral legitimacy of the animal rights argument.

The closest he comes is to compare meat-eating with slave-holding, in the sense that many obviously moral people during slavery days held slaves out of social convention, even though they knew it was wrong. The problem with that argument, though, is that meat-eating is far less of a socio-economic "necessity" than slavery arguably was for some slave-holders. Slave-holders faced (or reasonably believed they faced) real economic consequences for themselves and their families by emancipating their slaves. Meat-eaters have no such obstacle in their way; aside from farmers and ag-business types, no one's livelihood depends on meat-eating. So, Dawkins' argument here is even lamer than it sounds at first.

Singer is spot-on, I think, that Dawkins (and by implication, most other "evolutionists") clings to vestiges of religious belief about the specialness of humanity as a way of justifying the eating of animals to himself. I wish he had pushed Dawkins a bit more in this point, but it was Dawkins' show, not his.

On the whole, though, this is a fascinating interview. Pencil it in.

Round-up of Paleo Links

2011-06-17T15:40:00.000-07:00

The creeping cancer of creationism is infecting Geological Society field trips: Paleontology began as, and largely remains, a sub-field of geology, but gets more press attention and public scrutiny than its parent discipline. Which is too bad, because the dearth of public interest in geology allows deceitful creationists some cover and makes it easier for them to lie to the public. Take this quote from six-million-dollar stone cold creationist Steve Austin, one of the leaders of a recent GSA field trip: "these rocks were 'not normal deposits,' and likely formed as fast, liquefied and pressurized subaqueous mudflows during catastrophic flood flows." Sounds like science, right? But it's not, at least, not in context. Geology is slowly becoming the latest frontline in the battle between creationism and reality.

The bird-crocodile family tree appears to have split earlier than previously thought: This one speaks for itself. I've long suspected that archosaurs existed in the Permian -- logically, it makes perfect sense -- but as yet no one has found any fossils (keeping my fingers crossed) to bolster the case.

Did Stephen Jay Gould mismeasure man?: This one hits really close to home for me. Gould's The Mismeasure Of Man was one of the formative texts of my paleo-consciousness, and remains one of the few evolution books I re-read on a regular basis. Now, it seems, he might have been wrong all along. Them's fighting words (rolls up sleeves...)!

It's Official: I'm Famous

2011-06-17T14:56:00.000-07:00

Well, not really. However, I have accrued enough notice to get interviewed by Rhys Southan at Let The Eat Meat. Rhys is one of the most cogent, effective and fair-minded frenemies of veganism, and a hell of a good writer. His blog will force you to think hard about your veganism, and is all the more valuable for it.

At the end of the day, though, he's still wrong. :)

Empathy & Evolution: Did Loving Animals Make Us Human?

2011-06-11T11:02:00.000-07:00

Call it the pet theory, literally. Pat Shipman, an anthropologist at Penn State University, has put forth a new hypothesis based on the rather ingenious tactic of stating the obvious: alone among mammals, H. sapiens form deep social, ecological, emotional and even familial bonds with animals from other species. This trait is universal among humans, and thus must be ancient in its origins. So far, so good; most researchers would not argue with this observation.

But Shipman takes it a step further and argues that our unique ability to empathize and form bonds with other animals drove our evolution to such a degree that it played a central role in the invention of stone tools, language and symbolism, and domestication. In short, that it made humans human. She calls this trait the animal connection, and in addition to her initial review paper, has made it the subject of a new book.

According to Shipman, the adoption of a more carnivorous diet by the genus Homo about 2.6 million years ago required this former prey species to start depending on accurate observations of other animals to obtain more meat. Thus, a selective pressure arose favoring those hominins capable of understanding and empathizing with non-hominin species, which made them more effective hunters. This led, in turn, to the development of stone tools, used not just for hunting, but possibly also for anatomical study of carcasses. From there, the need to share complex information about animals led to the invention of language, and eventually reached ultimate fruition with the domestication of canids about 32,000 years ago.

Her thoughts about dogs are insightful: if the point of domestication was to make meat-acquisition easier, as has generally been supposed -- that is, if it was meant to reduce the risks of hunting by simply growing our own meat at home -- why then were wolves the first animals to be brought into human society? Wolves (who later became dogs) eat a lot of meat on their own, and are dangerous predators in their own right. From the perspective of evolution, domestication of a predator is maladaptive: it uses up a lot of your resources and calories, poses a danger to your offspring, and competes with you for food. Shipman maintains that animal domestication was essentially the invention of "living tools," an extension of our ability and desire to shape our environment to our needs. In this model, domesticated canids became extensions of our spears, an effective way of defending our homes and acquiring larger prey to feed more people. Ultimately, this allowed us to support larger, more settled populations and invent agriculture.

"Clearly," Shipman argues:

humans who handled and lived with animals more successfully accrued a selective advantage in performing tasks that humans without animals could not achieve. Domestication was reciprocal, as the animals in turn selected for behavioral or physical traits in humans, such as better communication with animals and the continued functioning of lactase into adulthood....

In this phase, the animal connection gave a selective advantage to humans who had better abilities to observe, to communicate, and to make a new sort of living tool. These abilities pre-adapted humans to live in higher densities and more permanent settlements, as happened once domestication of plants and stock animals occurred.

My initial reaction to Shipman's idea was to ponder the paradox it highlights. According to her hypothesis, our capacity to empathize with, love and care for other animals as though they were members of our own family arose in within the context of increased meat-eating by our distant ancestors. In other words, the ancient roots of animal rights ideas may lie in the birth of the one behavior by which all animal rights people are horrified.

To me, it's an excellent demonstration of exaptation. We evolved the capacity to empathize with other animals so that we could more effectively exploit them; but it is that very capacity that now allows some humans to ponder the folly of our ways and espouse animal liberation on the basis of our natural capacity for empathy.

In other words, animal exploitation and animal liberation may be two applications of a single evolutionary trait: our ability to make cross-species connections with other animals!

There's a lot to think about here, and I'm certain this won't be the last we hear of Shipman's hypothesis. Based on the responses in her review paper, the idea has received a generally positive reception among her colleagues. I look forward to reading her book and getting a more in-depth treatment. In light of her ideas, it will be interesting to see where she stands on current animal issues.

The Vocabulary Of Deep Time

2011-06-04T17:41:00.000-07:00

The more I study paleontology and evolution, the more I find myself taking language for granted. I have begun to casually and habitually use words that have specific meanings for paleontologists and evolutionary biologists, but that mean something quite different in colloquial speech. Understandably, this sows a bit of confusion now and then.

Take the words "ancestral" and "primitive," for instance. In several recent off-line contexts -- and one online one: my debate with Permavegan -- I have used one or the other of these words to describe some trait of humans that my interlocutor takes to be important in our evolution. On this blog, the relevant trait has been meat-eating or omnivory. I have pointed out that some degree of meat-eating behavior is "ancestral" to primates.

Some people take that statement to mean, "humans evolved to eat meat," but that's not actually what it says at all.

In paleontology, the words "ancestral" and (more commonly) "primitive" describe traits that are so evolutionarily deep that they are no longer distinctive enough to define a species. The words are contrasted with "derived" traits, which can be used to define a species (or other taxon).

The distinction is subtle, but important, and perhaps best illustrated by an example.

Let's say we are comparing humans and chimps, trying to determine how related they are to each other, and which of their respective traits should be used to define them as separate species.

Because they are both primates, there will unavoidably be traits that both chimps and humans share with other primates (say, opposable thumbs). Such traits -- shared by all primates, not just chimps and humans -- would be called "primitive" or "ancestral" for chimps and humans, because they are shared by all other primates, as well. Thus, these traits do not distinguish chimps and humans from other primates; they are, as it were, nothing special.

On the other hand, both chimps and humans are also going to have traits unique to themselves and to no other species (humans, for instance, are obligate bipeds, unique among primates). Such traits -- possessed by only one species (or taxon) but no others -- are called "derived" traits, because though they may be unique to that species or taxon, they were developed from a history that nonetheless relates them to other taxa.

Finally, there are going to be traits that chimps and humans share with each other, but with no other primate species. Such traits, shared by two species within the same taxon but not with others in that taxon, are "shared derived" traits, which they each inherited from their most recent common ancestor.

This distinction between ancestral/primitive, derived and shared derived traits is one that almost never turns up in colloquial discussions of evolution. In the context of the debate between vegans and carnists, for instance, each side will produce laundry lists of traits designed to prove that modern humans are "meant" to eat specific foods. Yet, neither camp makes any effort to distinguish whether their pet traits are ancestral, derived or shared derived, which muddies the whole discussion.

For example, I recently encountered a hunter who insisted that humans are meant to eat meat because our pancreas produces elastase, an enzyme that breaks down the proteins used to build and maintain connective tissues. This, as far as he was concerned, closed the case.

When I pointed out to him that elastase production is a primitive trait for all jawed vertebrates (because we are all ultimately descended from carnivorous fish), he didn't get the point, which was that because it is nearly universal in the vertebrate world, elastase cannot be used to define H. sapiens as an obligate carnivore. Natural selection is conservative, and nearly all jawed vertebrates -- even cows! -- retain the elastase-producing trait because it hasn't proved to be a constraint on their evolution.

Pick any trait you desire, be you a vegan or a carnist. Before you can plausibly argue that your pet trait proves something distinctive -- and thus definitive -- about modern humans, you're going to have to establish that the trait is derived (or at best, shared derived) for us. This is done by reference to the fossil record and (increasingly) genome analysis.

In the case of most traits cited by either camp, this will prove impossible, since the majority of traits possessed by H. sapiens are either ancestral/primitive or shared derived.

But, it doesn't stop there! In addition to establishing the primitive or derived nature of trait, you're also going to have to avoid a common fallacy called adaptationism, which argues that every single trait of an organism exists because it played an adaptive role in that organism's evolution; or, relatedly, that the modern use of a trait necessarily points to its adaptive history.

Not all traits are adaptations for a given organism. Many, if not most of them, were simply retained by all descendants of a common ancestor because the trait did not pose a hindrance to their evolutionary fitness. And what's more, such traits may get co-opted into new uses, or prove to be beneficial in new contexts separate from the selective pressures under which they originally arose.

A classic example is feathers, currently used by birds to achieve flight. It's tempting to think that flight is the "purpose" of feathers, but the fossil record shows us that the species of dinosaurs from whom birds descended developed feathers millions of years before they developed flight. So, why feathers? The prevailing hypothesis is that feathers developed as a method of thermoregulation, and only later got co-opted in the development of flight. Whatever the case, the fact that feathers are far more ancient than flight among dinosaurs indicates that flight was not the "purpose" of feathers.

A similar situation applies to an array of human traits often cited as evidence that we are "meant" to eat specific foods, such as canine teeth and binocular color vision (perennial faves among carnists), or small intestine length and stomach pH of 4 to 5 (popular among vegans). The fact that we possess these traits does not, in itself, mean that those traits were adaptive for our species in particular; nor does the fact that we currently use these traits in particular ways mean that those uses were what the traits were "meant" for. The likeliest explanation for a given trait is that it represents an adaptation to the environment of some distant ancestor, not to our own, and that we retained it because it posed no obstacle to our own evolution.

Modern humans are a patchwork of primitive and shared derived traits, most of which didn't arise in response to selective pressures faced by H. sapiens in particular. When defining what makes us uniquely human, it's only going to be our derived traits that count. Most carnist and vegan pundits miss this point, and are probably unaware that the distinction exists at all.

We should all keep this in mind when making appeals to evolution to defend our veganism, and be circumspect when making claims about what nature "intends" us to eat. There's nothing to fear in admitting that meat-eating is ancestral for humans; at best, it concedes a capacity for digesting animals, not an obligation to do so.

On the other hand, I have found using this distinction to be a lot of fun when confronting antagonistic armchair anthropologists, proclaiming from their self-presumed expertise that humans are "designed" to eat meat. Even knowing about this primitive-vs.-derived distinction in a cursory way can be enough for you to confound their presumption, and pull a Will Hunting on them. Just challenge them to demonstrate that their pet human trait is derived rather than primitive, and watch the apoplectics ensue.

Fallback Food Fight: Of Course, The Experts Say It Better

2011-05-28T10:58:00.000-07:00

I knew it was out there somewhere. A couple of years ago, I read a paper by Richard Wrangham and "some other dude" (as I called him after I forgot his name) that laid out fairly rigorous definitions of fallback food and preferred food. It was that paper that informed my position in this debate with the Permavegan, but I hadn't been able to remember where I'd read it.

Well, while doing research on Google Scholar for an upcoming post on chimp vs. human evolution, I found the long-lost paper in question, Evolutionary Consequences of Fallback Foods. And it's worth quoting extensively, for clarity's sake (emphasis added):

Although FBFs are not always operationally defined, the term most often refers to items assumed to be of relatively poor nutritional quality and high abundance, eaten particularly during periods when preferred foods are scarce (Hanya 2004; Knott 2005; Laden and Wrangham 2005; Lambert et al. 2004; Ungar 2004, Yamakoshi 2004a).

Accordingly, one can operationally define FBFs as foods whose use is negatively correlated with the availability of preferred foods (cf. Altmann 1998; Conklin-Brittain et al. 1998; Doran et al. 2002). Two points about the concept should be stressed. First, the definition of fallback foods implies a distinction between preference and importance. Whereas preference is a matter of dietary choice, importance is a measure of dietary composition. For example, the importance of a particular item might refer to its use as a proportion of total caloric intake, or the percentage of total feeding time spent eating it. Although preferred foods are in some circumstances important, they need not be, as illustrated in Table I. Similarly, high importance of an item in the diet does not necessarily imply positive selectivity or high preference. Fallback foods tend to be foods of low preference but of high importance seasonally.

This is the distinction I was driving at in my "Definitions & Clarifications" post. I.e., the fact that a primate regularly eats a large amount of a given food does not necessarily make that food "preferred," nor does infrequency of consumption make a given food "fallback."

So, if a fallback food is "negatively correlated with the availability of preferred food," what then is a preferred food according to Marshall & Wrangham?

We advocate a classic definition: preferred items are overselected. In other words, preferred food items are selected disproportionately often relative to their abundance within the population’s habitat (Leighton 1993; Manly et al. 2002). Thus, preference is defined as the relationship between 2 parameters: availability and usage. Neither rarity nor frequent utilization is alone sufficient to characterize a food as preferred.

Fallback foods influence adaptations for processing (i.e., mastication, digestion, etc.) and preferred foods influence adaptations for harvesting (i.e., locomotion, tool use, etc.).

On the question of whether meat was a "fallback food of last resort," as the Permavegan contends, much will depend on which stage of hominin evolution we choose to focus on. To me, it is clear that by the time Homo arrives on the scene, meat is a preferred food, often over-selected (at the end of the Pleistocene, to great ecological detriment) as our intelligence and technological capacities made us more efficient hunters.

For the australopiths, the picture is a bit murkier. There is some evidence that they ate meat, but whether it served as a preferred food or a fallback food for them is open to debate, which I guess is what this little tete-a-tete between vegans is all about.

But that gives us the additional problem of trying to decide which australopiths or other pre-Homo species we decide to claim is ancestral -- and thus, most relevant -- to Homo. And I don't think we're going to figure that one out any time soon.

Sniffing Made Mammals Smart?

2011-05-21T12:10:00.000-07:00

Paleontologists have now discovered that an improved sense of smell jump-started brain evolution in the ancestral cousins of present-day mammals.

Fallback Food Fight: Defintions & Clarifications

2011-05-20T18:23:00.000-07:00

I blame myself. It seems that despite my best efforts, the Permavegan and I have been talking past each other. His latest response in our ongoing debate reveals this quite clearly; in the first half of his article, the Permavegan calls me to the carpet about the imprecise use of language:

In the above passage, the Humane Hominid is not using the terms preferred food and fallback food in a manner that is consistent with optimal foraging theory, or with the understanding of fallback foods that emerged during early primatological studies, as I cited from Constantino and Wright (2009) in my contribution to round two:
The fallback food concept appeared relatively early in primatology. It seems to have been introduced by Hladik (1973) who was commenting on chimpanzees’ increased consumption of leaves and stems during periods of low fruit abundance (Tutin et al., 1985). Although the term ‘‘fallback food’’ does not seem to have been widely used at this time, seasonal variation in primate diets quickly became a regular part of primate feeding studies (e.g., Waser, 1975; Chivers, 1977; Fossey and Harcourt, 1977; Hladik, 1977; Wrangham, 1977). These studies made it clear that most primate diets shifted seasonally, even in species living in ‘‘stable’’ tropical forests (Hladik, 1988). In light of optimal foraging theory (MacArthur and Pianka, 1966), researchers also recognized that certain primate foods should be more ‘‘preferred’’ than others. For example, in a study of the feeding behavior of Bornean orangutans, Rodman (1977) discussed the difference between ‘‘preferred’’ and ‘‘less preferred’’ foods and argued that bark was less preferred than fruit because it has a lower energy yield and greater cost of procurement. The combination of these two concepts, dietary seasonality and the prioritization of food resources, led to the understanding that many primates experience a particular time of the year when preferred foods are in short supply and that certain fallback foods can be critical for the survival of these populations (Leighton and Leighton, 1983).

In the case of chimpanzees and Bornean orangutans, the staple food of fruit is defined as the preferred food, and those plant foods which have a lower energy yield, are more costly to procure, or are relied upon during periods of seasonal stress are designated less preferred or fallback foods. Curiously, the Humane Hominid admits that "fruits, tubers and seeds" were what our hominin ancestors "depended on most of the time for our daily survival," but for some reason he is not comfortable referring to these plant-based foods as preferred foods!

But, it doesn't stop there! Next, he points out another apparent contradiction on my part:

On the other side of the inversion - that meat is a preferred food in the hominin diet - the Humane Hominid responded to my round two challenge as follows (emphasis added):
This question -- and all four of its sub-questions -- seem to me premised on a single, probably flawed, assumption: that there was ever a time that hominins didn't eat other animals. I am skeptical that any such time ever existed. As far as we can tell, hominins...have always been at least somewhat behaviorally carnivorous.
This rather subdued appeal to peripheral behavioral carnivorism is a completely different assertion than the earlier proposition that plant-based staples were the fallback foods and meat was the preferred food for our line of descent.

To the first part of this implicit charge, I must plead guilty. My definition of "fallback food" was indeed imprecise, leading to the present confusion. So, let's back up a bit.

Floating around unspoken in my mind during our debate thus far has been the definition of fallback food summarized in the paper by Marshall, et. al., to which I had linked in my first installment (emphasis added):

Physical anthropologists use the term ‘‘fallback foods’’ to denote resources of relatively poor nutritional quality that become particularly important dietary components during periods when preferred foods are scarce.

Also, Richard Wrangham's summary of the definition influenced my responses (again, emphasis added):

The term fallback foods refer to foods poor in nutritional value compared to preferred foods and ones that become important in the diet when preferred OR commonly eaten foods are unavailable. Operationally, however, the term is used more broadly. For example, Hadza foragers take more tubers (USOs) when honey, meat, berries, and baobab are less available, yet tubers are eaten in all seasons constituting a significant portion of total diet. In contrast, core diet components for yellow baboon are defined as anything taken in amounts >1%. The concept should prove useful once a consistent definition is accepted by users.

As can be seen by Wrangham's final sentence, as well as a close reading of the Marshall, et. al., paper, anthropologists haven't yet settled on a single precise definition of the term. But they are getting close, and key to both major proposed definitions is the concept of "dietary quality" or "nutritional value," meaning not how healthy a particular food is for a given individual, but which ones are the most calorically-dense; i.e., which foods provide more energy than it takes to acquire them. I neglected to emphasize this point in both of my responses, and so I must ask the Permavegan's and the reader's forgiveness for the confusion this caused.

That a food is eaten as a staple, or seasonally, does not by itself make it a preferred food. Nor need fallback foods be eaten rarely; after all, I prefer vegan chocolate chip cookies by the bag-full, but I rarely eat them. Whether a food is considered fallback or preferred depends on "dietary quality" as well as, if not more than, frequency of consumption.

Fallback foods are food sources of low energy pay-off that a species uses to "get by" during lean times. They are often (though not always) eaten more frequently than preferred foods, or common foods with higher nutrient densities, and for this reason sometimes appear to influence a species' evolution.

Once we understand that the key issue here is nutritional quality, we can see that there's actually no contradiction my two seemingly incongruous comments. Primates will go to great lengths to procure a preferred food, though some are lucky enough to have their preferred foods available to them for long periods of time (I could, for instance, go to Trader Joe's right now and have a good chance of finding a bag of vegan chocolate chip cookies; thus, for minimal effort, I can acquire a tasty food that's high in calories). They will also fall back on less-preferred foods when the more-preferred ones are scarce (maybe Trader Joe's is out of vegan cookies, so I go back home and make a whole-food smoothie instead). The foods they adopt during these scarce times might actually be calorie-dense themselves (like fruits and tubers), but if they're less calorie-dense than the more-preferred foods, they'd be classified as fallbacks.

Admittedly, I find it all a bit arbitrary, and have complaints that it seems to simply assume (without testing) that meat was a better energy deal for hominins than calorie-dense plant foods were. But here, paleontologists can only work with the evidence they have; it's impossible to test how efficient, say, Homo ergaster was at digesting meat compared to plants. The best we can do is look at current human characteristics in comparison to those of other extant primates, and extrapolate logically backward into the fossil record, using the scientific method to look for clues in the morphology of our ancestors and the rock record of their enviornment. I'll deal with that issue later, though. Right now, we should focus on getting our definitions straight.

When I echo the standard anthropologist line that meat is properly classified as a preferred food for hominins -- or at least for the genus Homo -- I am not necessarily saying that meat was commonly eaten, or easier to acquire than plant foods (though again, much depends on which hominin species one wishes to emphasize). I am simply thinking of the caloric pay-off that meat -- particularly cooked meat -- granted to early humans, for which they demonstrated a growing preference over evolutionary time, affecting both their dental morphology and behavior, culminating in the great megafaunal extinctions of the late Pleistocene. In short, as Homo's ancestors and then Homo themselves became better at tool-use and hunting, meat-acquisition no longer violated the parameters optimal foraging theory because they could spend progressively less energy in the effort, and meat thus became increasingly preferred. That's the standard paleontological view of human evolution, and one that I think is pretty much in accord with the fossil evidence, subject to the caveats I offered in my last post on this topic.

So, to re-iterate, I have been assuming that the term fallback food refers to food of low nutritional quality that an animal relies on at times when preferred foods are scarce. Preferred foods are foods of high nutritional quality that may or may not be eaten regularly. So, when the Permavegan pauses to ask me directly:

when we are talking just about the plant-based portion of the chimp diet, isn't it most logical to describe the staple fruits and greens as the preferred foods, and relegate the pith, bark, and seeds to the fallback food category - especially to the extent the latter foods are consumed during lean, dry seasons, when the former foods are scarce or unavailable?

I would answer "yes, absolutely. That, however, does not mean that the rarely-consumed meat in chimp diets is also a fallback food. Whether food is classed as fallback or preferred depends on the food's nutritional quality as well as the frequency of its consumption."

All In The Family?
Before we close, however, another terminological question looms. The Permavegan notes:

I am confident it is just a slip of the tongue in the Humane Hominid's exposition, but my understanding is that chimps, bonobos, and humans are indeed all hominins.

This confusion stems from a proposal by a team at Wayne State University School of Medicine in Detroit, Michigan, to re-classify chimps as members of genus Homo based on genetic similarity. Wikipedia treats this proposal as though it's been accepted, including chimps and bonobos in the taxon, but in fact, it is still being debated. Linnaean classification is traditionally based on morphological rather than genetic characters, and as of this writing, chimps and bonobos have not been incorporated into the tribe Hominini* (though I would not be opposed to this proposed change).

So, to the second half of the Permavegan's implicit charge, I plead not guilty, and instead blame the system.

Much of this common misunderstanding has to do with the use of Latin suffixes in taxonomy. While it is true that humans, chimps, bonobos and gorillas are grouped together in the subfamily Homininae, they are not all part of the tribe Hominini. The Homininae are divided into the tribes of Gorillini (gorillas), Hominini (humans and their fossil ancestors) and Panini (chimps and bonobos and their fossil ancestors). Roughly speaking, the word "hominin" now refers to what used to be called "hominid"; that is, H. sapiens and their extinct fossil ancestors, including all of the genera Homo and Australopithecus, along with Paranthropus, Ardipithecus, Kenyathropus, and the various other ancient forms.

I hope this helps clear some of the cobwebs out of our discussion, especially since the Permavegan has had much to say over the last week about other topics touched on in my last response, such as vegan bias in this debate, whether veganism is an exclusively modern ethical stance, and whether our ancestors' diet has moral implications for us today. Rather than devote blog space to each of these questions here, I will attempt to address them in the comments section of the Permavegan's blog and save Paleoveganology for the main spine of our discussion.

So, keep checking his site, and be on the look out here for further installments. I won't move on to a discussion of chimps vs. humans until we have sorted out this terminological issue.

*This is why I prefer Citizendium, where expert review carries some proper weight, over Wikipedia, and always check it first when looking for explanatory links.

What, No Bugs?! -- Paleo-Diet Paper Reveals Glaring Blind Spot

2011-05-14T15:56:00.000-07:00

I don't pay as much attention to the "paleo diet" blogosphere as I probably should, seeing as how my humble blog now appears on their Paleobuzz site... so it took me a while to come across this paper written by several head honchos of the paleo diet movement. From what I can tell, it hasn't been discussed too much on any of the paleo-diet blogs.

Now maybe that's because because I don't pay much attention to them and simply haven't noticed. Or maybe it's because the authors undermine an important tenet of the "paleo-diet's" paleofantastical view of the Stone Age:

Secondly, in contrast to common belief, hunting probably played a less dominant role from a nutritional point of view compared with gathering, and on average, it makes up 35% of the subsistence base for present-day worldwide hunter–gatherers, independent of latitude or
environment(27,37). For example, hunting by some surviving hunter–gatherers is still not very successful: the probability for a kill in !Kung bushmen is only 23%(37), and the subsistence of Hadzabe, as described by Woodburn(39), consists of 80% plant foods. In the Paleolithic, however, hunting might have been more productive, due to both higher animal biomass and hunter–gatherers not being displaced to marginal environments, unattractive for crop cultivation or cattle. Consequently, we chose the employed ratios within the range of the most commonly observed hunter–gatherer subsistence ratios(26,27).

In other words, if extant hunter-gatherers equipped with advanced stone tools and modern weapons have such low hunting success rates, it's probably not reasonable to assume that Paleolithic ones did much better. They likely relied more on subsistence plant foods and scavenged meats than they did on big game hunting. This notion contradicts a great deal of what I, at least, have seen in my brief sojourns through the paleo-diet realm, where you'd think hominids are descended from wolves or something, the way resident armchair anthropologists lionize paleo-hunting at the expense of paleo-gathering.

For this reason, the team exclude from their studied ranges the possibility of Paleolithic diets gaining more than 70 percent of the their energy from animal-derived sources; a higher percentage seems inconceivable to them, given the technological constraints they note (to their credit). Personally, I'd say even the 70 percent range is being awfully generous, and would set the upper possible range no higher than 50 percent, and even that would be pushing it.

But that's just splitting hairs. What's more interesting to me about this paper isn't which foods it includes, but which ones it leaves out. The team focus their models on the conundrum of whether early man met his protein and fatty acid needs through various ratios of fish-to-plants-to-terrestrial mammal organs; and in doing so, they unknowingly reveal a confirmation bias in favor of the sorts of animals that modern Western humans prefer to eat.

In short, there are no bugs or worms in this paper. It's as though someone took a big can of Raid to the authors' paleo-imaginations. So steeped are they in their Western food bias and paleofantasies that the possibility of Paleolithic man fulfilling his nutrient requirements with a diet of creepy-crawlies never occurred to them.

But it should have. Insects, grubs, worms and other terrestrial invertebrates have long provided humans and other primates with nutrients, and continue doing so today in most parts of the world. The UN, at least, if not the paleo-diet movement, has taken notice.

What's more, insects have essential fatty acid and protein profiles comparable to poultry and fish. There's no good reason terrestrial invertebrates -- hell, let's just call them "bugs" -- should be excluded either from studies or lifestyles that purport to replicate H. sapiens' "ancestral" diet. But they usually are.

For the most part, bugs remain invisible to such researchers, and to the movement they spawned. By and large, paleo-diet bloggers and writers focus on the traditional American meat sources and indulge themselves in fantasies of a Paleolithic populated by spear-toting personal trainers. Bug-eating just doesn't sell books, I guess.

Entomophagy is conspicuously absent from this "paleo-diet" study, as it is from most of the paleo-diet movement that I have seen. And further, this study itself has been conspicuously absent from the "paleo" blogosphere. Both absences tell us more about the confirmation biases and paleofantasies of modern Western humans than the study itself can ever tell us about the trophic strategies of Paleolithic hominids.

I, of course, do not advocate eating insects or any other animals. But that's just me, and a bunch of other wacky vegans. Nonetheless, I'd be interested to see how popular these (allegedly) "paleo"-diet authors and bloggers would remain if they started admitting that the Paleolithic diet was probably more Fear Factor than Fat Head.

At least National Geographic, bless them, was kind enough to lend a pre-emptive helping hand with some handy bug recipes. Eat that, Cordain, Eaton, et. al.

What's In A Nomen?

2011-05-10T15:58:00.000-07:00

I'm considering a name change, both to my handle and to the blog itself. I'd keep the same URL, but part of me thinks the current title gives too much of the wrong impression, as though I'm trying to say there's a necessary connection between paleontology and veganism.

The new name, and possibly the new avatar handle as well, would be The Humane Hominid.

I'd love some feedback from my readers about it. What do y'all think?

Forks Over Knives: A Reflection

2011-05-07T22:40:00.000-07:00

I'll concede, I went in a little dubious. The health argument for veganism ultimately fails, not because veganism is unhealthy, but because framing veganism primarily as a "diet" or medical treatment restricts its appeal to those who are either sick and seeking "alternative" therapies; or vain, and chasing the latest fad. This approach obscures the ethical argument that's the basis of veganism (that applies to everyone), and only nominally makes a positive impact for exploited animals. As Ginny Messina puts it:

The counter-argument to all of this, of course, is that getting people to go vegan for any reason is a good thing. It reduces animal use and it helps shift paradigms about food choices—which can eventually open minds to the issue of animal liberation. I’m in favor of most efforts and campaigns that do those things. But here is the problem with using the health argument in this way—it’s that there isn’t any health argument for veganism.
There is, of course, a pretty good argument for eating more plants (lots more plants) and less animal food, but no one has shown that you must eat a 100 percent plant diet in order to be healthy. So to make an argument for a 100% vegan diet based on health benefits alone, we have no choice but to stretch the truth. We have to overstate the benefits of vegan diets, and sometimes minimize or dismiss the risks. And as soon as we stray from actual facts, our advocacy is on shaky ground.

So, I was glad to see a (brief) interview with Gary Baur of Farm Sanctuary, and a nod (however grudging) to the animal rights argument. I was also glad to see that the film restricts itself mostly to the phrase "whole-foods, plant-based diet" rather than "vegan" (in fact, the only person in the whole film who utters the word "vegan" is Mac Danzig, and you know better than to correct him...). The first because I think the ethical argument should always be front and center, and we shouldn't be playing a shell game with people, tricking them into the subculture. And the second because, as Messina says, the argument for a whole foods, plant-based diet, however strong, is not in itself an argument for veganism.

Mixed feelings aside, I still recommend the film. It's an engaging and moving portrait of Drs. T. Colin Cambpell and Caldwell Esselstyn, and the people whose lives they've saved with their approach. I found it particularly poignant that both men grew up on dairy farms, then had their minds changed by evidence and experience. It helped me see them not as advocates for a cause, but as honest scientists promoting their work.

And thankfully, there's zero talk about homeopathy, naturopathy and other forms of unproven, unethical quackery; and only a brief bit of borderline conspiracy thinking.

Overall, it's a great documentary that will probably convince a lot of people that they need to eat lots more plants. I'm not sure how much it will help the animal rights movement, but at least Mac Danzig will keep kicking ass for the film's audience on TV.

Not a perfect film for the vegan cause, but we can't all be Earthlings.

Back Atcha, PermaVegan! -- Fallback Food Fight, Round 2

2011-05-07T20:54:00.000-07:00

Image courtesy of Kenyathropus.com

I should thank the PermaVegan for engaging me in this debate, for it has goaded me into performing one of the most essential elements of scientific thinking: arguing against one's own bias. In contemplating and researching a response to his latest entry, I realized that I, like many vegans, was clinging to the hope that our hominin ancestors were herbivorous. Consciously, I knew this wasn't exactly true, but emotionally, I wanted it to be true. And thus, what I'm about to do feels like a betrayal, even though it isn't. Veganism, as I've said, is a modern ethical stance, formulated in response to modern challenges. What our ancestors ate isn't morally or ethically relevant.

Nonetheless, the PermaVegan asks a good question, in four parts, that deserves a robust answer:

My question, though simple - "How do you resolve the abrupt evolutionary reversal that appears to be implied in a proposed hominin preference for meat?" - is best introduced in four parts:

As you read the scientific literature, what is the earliest date (in millions of years ago, or Mya) for which you think it is reasonable to argue that our line of descent was frugivorous/folivorous?
By what date, approximately, do you believe our line of descent can be said to have demonstrated a dietary preference for meat over fruits and vegetables?
How do you argue that a new preference for the consumption of meat over fruits and vegetables arose prior to a generalized or plant-foraging adaptation that only secondarily made meat acquisition a marginally better energy deal in times of fruit and vegetable scarcity?
As a result of what major environmental and/or genetic modification do you believe the consumption of meat became a more optimal foraging strategy (in net energy terms) than the acquisition of previously preferred plant-based foods?

This question -- and all four of its sub-questions -- seem to me premised on a single, probably flawed, assumption: that there was ever a time that hominins didn't eat other animals. I am skeptical that any such time ever existed. As far as we can tell, hominins (as opposed to hominids; see the addendum, below) have always been at least somewhat behaviorally carnivorous.

Before getting into the meat of the matter, as it were, I should offer a few caveats, all of which you should keep in mind whenever you read any article on the subject of diet and human evolution:

The fossil record of hominin evolution is spotty, relying heavily on incomplete skeletal remains and teeth. Thus, conclusions about diet drawn from it are tentative.
The fossil record is biased in favor of meat-eating evidence. Bones and teeth fossilize more readily than plant material or soft body parts. This, again, is a reason to draw only tentative conclusions about the relative importance of meat in hominin diets; aside from isotopic data (which has its own issues), evidence about the prominence of plant foods in hominin diets simply doesn't preserve as well. Thus, we run the risk of over-stating the case for meat.
The evolutionary relationships between hominin taxa are murky, and still controversial. Anthropologists still argue over which lineages are ancestral to Homo. So, again, conclusions must be tentative.

Bearing that in mind, however, the fossil record does give us good indications of early hominin diets... but the catch is deciding precisely which hominin taxa are directly relevant to the case. It's always been assumed (reasonably) that at least some of the australopithecines were direct ancestors of genus Homo. As a result, the debate over just how carnivorous our ancestors were has tended to focus on the question of which australopith was most likely to be our ancestor. Those who preferred the interpretation that A. afarensis was a direct ancestor of all subsequent hominins gave points to the vegan camp (whether they knew it or not), while those who preferred the interpretation that A. africanus wasn't descended directly from A. afarensis but was ancestral to Homo gave points to the carnist camp (whether they knew it or not).

But, a few recent fossil finds have cast doubt on whether the australopiths were actually our ancestors at all; turns out, they might have just been a sister taxa to the Homo line, and thus an evolutionary dead-end with no direct relevance to us.Which, if true, means that the hominins actually related to us were (slightly) more carnivorous than their australopith cousins.

Consider Kenyanthropus platyops, discovered in 1999 by Justus Erus, working on Maeve Leakey's team (yes, of those Leakeys!) at Lake Turkana, Kenya. This enigmatic hominin discovery sparked a debate that rages to this day. Leakey's team suggested then, and still do today, that Kenyathropus deserved its own genus, and may have been an ancestor of Homo rudolfensis. This suggestion would take Homo out of the australopith line of descent altogether, and turn australopiths into an evolutionary dead-end; a radical move! Understandably, other paleoanthropologists dispute their findings, and the issue has not been settled.

Kenyanthropus and its descendants had teeth adapted to a diet of soft, rich foods like tubers, fruits and meat. And if it really is its own genus separate from australopithecines, as the Leakey team suggests, then its dental adaptations would have been inherited from as-yet-undiscovered, non-australopithecine hominin ancestors going all the way back to the chimp-human divergence. And that means, in turn, that the omnivorous capability of our Homo lineage has been with us for 7 million years.

While we're on the topic of omnivory, now would be a good time to point out another concept that needs clarification: the presumed conflict between a frugivorous and an ominvorous morphology. The PermaVegan -- and many other fellow vegans, as well as most carnist armchair anthropologists -- talk about them as if they are different things, but they're not. At least, not exactly.

Among mammals, herbivory and carnivory are both highly specialized adaptations, viewable in the dental and (among extant species) gut morphologies of the relevant species. Frugivory has always been considered intermediate between the two; as Hladik, et. al., noted in their critique of the expensive-tissue hypothesis:

The “faunivore” trend, as well as the “folivore” trend, are morphological specialization – corresponding to different allometric relationships – that are not likely to allow a large plasticity, as for any specialized character. A specialized carnivorous adaptation in humans that would correspond to a minimized gut size is obviously not supported by our data (fig. 1). Large variations presently observed in human diets (Hladik and Simmen, 1996) are probably allowed by our gut morphology as an unspecialized type of “frugivore”, a flexibility allowing Pygmies, Inuit, and several other populations, present and past, to feed extensively on animal matter, for whom most of the energy is mostly derived from fat (Speth, 1987).

In other words, modern human guts are adapted to a diet of soft, energy-dense foods, a condition they inherited from "frugivorous" ancestors but that accidentally also allows them to be better at digesting meat than other primates. To put it succinctly, H. sapiens are functionally omnivorous because of their frugivory, not in spite of it (a point that threatens to undo the whole debate before it even starts)!

A final point to consider before I answer the PermaVegan's question directly is one I've raised before: the behavioral distinction between "herbivore," "omnivore" and "carnivore" isn't always clear-cut, and isn't always a reflection of skeletal or gut specializations. Witness, as evidence, the strange case of the meat-eating deer; or the lovable panda, a herbivorous carnivore.

So, in answer to the PermaVegan's core question -- "How do you resolve the abrupt evolutionary reversal that appears to be implied in a proposed hominin preference for meat?" -- I'd contend there really isn't any "abrupt reversal" that needs resolving. Hominins have always eaten other animals, to some degree or another. Modern chimps (who are hominids, not hominins, but still closely enough related to us that we can make reasonable inferences) are known to prefer meat whenever it's available to them or whenever they can catch prey; thus, we can reasonably assume that this preference is ancestral to Homo, as well. The burden of proof, I'd say, rests with those who contend that meat-eating is somehow anomalous among hominins... especially if the K. platyops evidence turns out in favor of the Leaky team's interpretation.

Of course, an ancestral behavior of meat-eating does not necessarily imply that meat made up the bulk of an extinct hominin species' daily diet; a great deal remains open to interpretation, and bias can always creep in. Which brings us to the PermaVegan's sub-questions:

1) As you read the scientific literature, what is the earliest date (in millions of years ago, or Mya) for which you think it is reasonable to argue that our line of descent was frugivorous/folivorous?
I'd say our line of descent has been frugivorous (not folivorous! -- they are different adaptions, and using them in the slash style, implying they're the same thing, is inaccurate) since about 55 Ma, during the Eocene radiation of the adapiformes. Many of these animals' descendants developed folivorous capabilities, it's true, but that's when the first reasonably-identifiable frugivorous adaptations (as distinct from their insectivorous ancestry) are notable.

2)By what date, approximately, do you believe our line of descent can be said to have demonstrated a dietary preference for meat over fruits and vegetables?
Subject to the caveats I offered earlier, I'd say around the same time as the PermaVegan and professional researchers do -- ca. 2.5 to 1.5 Ma. That's when the fossil record gives us robust, somewhat direct evidence that hominins were eating other animals. But again, it's likely this behavior has been with us right from the start.

3) How do you argue that a new preference for the consumption of meat over fruits and vegetables arose prior to a generalized or plant-foraging adaptation that only secondarily made meat acquisition a marginally better energy deal in times of fruit and vegetable scarcity?
Again, I'd argue that hominins have always had some preference for meat, and there's nothing "new" about it. This can be inferred from observations of chimpanzee hunting in the wild, and the fossil record of our dental development. My working mental model is that early hominins relied on fruit and tuber foraging most of the time, but snatched the opportunity for meat whenever they could... in a strategy similar to that of modern chimps.

4) As a result of what major environmental and/or genetic modification do you believe the consumption of meat became a more optimal foraging strategy (in net energy terms) than the acquisition of previously preferred plant-based foods?
The earliest robust evidence for hominin meat-eating appears towards the end of the Pliocene global cooling, which saw the decline of rain forests and the spread of arid grasslands and savannahs; and extends into the cold Pleistocene. The first hominin dental adaptations to a rich, soft-food diet appear a bit earlier than that, in the mid-Pliocene with K. platyops. I'd say that's when the shift began to happen, and wouldn't want to get more specific than that, because I don't think such a shift would have been "abrupt," as the PermaVegan described it. As noted, it's my evaluation that hominins have always had some preference for meat.

I realize this may not be what a lot of vegans want to hear. It's not what I want to hear, either. In my heart, I wish we had descended from purely herbivorous ancestors; if nothing else, it would make the case for veganism a bit easier. But I cannot ignore the evidence of the fossil record; that would be intellectually dishonest. The case for veganism -- or at least, my case for veganism -- isn't built on the details of human evolution. It doesn't have to be. The systems of animal and environmental exploitation we face today are unprecedented, and veganism is a form of conscientious objection from those systems. That it didn't exist in coherent form prior to the modern age should not trouble vegans any more than the absence of ancient Roman skyscrapers troubles architects.

ADDENDUM: Some readers may be confused by use of the words "hominid" and "hominin." The difference is easy to remember, though. Hominin refers to the ancestral line of Homo and all of its sister taxa except the great apes. Hominid includes Homo, its hominin relatives, and the great apes (and their ancestors). So, chimps and humans are both hominids, but only humans are hominins.

Your Inner Fish Is All Over Your Face

2011-05-06T11:05:00.000-07:00

Well, okay, it's mostly just on your philtrum, that little groove that runs from your nose to your upper lip. If you're like most people, you see it in the mirror every day and don't think much of it. If you're like me, you sometimes wonder, "WTF?"

Well, turns out the philtrum is an evolutionary remnant of our descent from bony, lobe-finned fishes. The BBC has an awesome (though unfortunately un-embeddable) video up today about the formation of the human face during gestation, when we go from looking like one of our fish ancestors to looking like us.

It's a bit freakish to look at, but all the more mesmerizing for it. The accompanying article also explains the fishy origin of hernias and hiccups, but they're explored much more in depth by Neil Shubin's excellent book, Your Inner Fish.

The Permavegan Retorts

2011-04-29T11:52:00.000-07:00

Permavegan has posted his first response to my critique of his hypothesis. Damn good evidence marshaled, and damn good questions asked.

It's refreshing to debate a knowledgeable opponent. Keeps you sharp. I should have a response prepared in about a week or so.

Listening To Pterosaurs

2011-04-23T20:12:00.000-07:00

Pterosaurs keep pecking at my brain. For months now, they've been haunting me, and it's felt like they were trying to raise a question other than, "who're you calling a dinosaur, bub?" I've been itching to say something on this blog about these fascinating animals, but I couldn't quite put my distal phalange on just what it ought to be.


Credit: Mark Witton, U. of Portsmouth

But Mrs. T has changed all that. Or maybe she's just clarified it for me.

It's her egg that did it. The poor girl died while pregnant, and as she decomposed, her egg was expelled from her body, then fossilized in its own right. And it turns out the egg isn't what we'd expected at all.

For years, researchers thought the reproductive cycle of pterosaurs was like that of modern birds: i.e., they laid eggs with shells that hardened on contact with air; they sat on nests and took care of hatchlings. But we now have solid evidence that that wasn't the case at all.

Mrs. T's egg was small and soft-shelled, like that of modern lizards and snakes. These animals generally bury their eggs after laying them, and the eggs receive moisture and nutrients from the surrounding soil. And what's more, the young reptile hatchlings are far more developed and self-sufficient than baby birds. The similarity between modern reptile eggs and pterosaurian eggs (or, at least, Darwinopterus eggs) indicates that pterosaur reproduction was more reptilian than avian.

In short, pterosaurs weren't dinosaurs, which means they weren't birds, either. And that, in turn, means that modern comparative anatomy tests on pterosaur flight that have tended to exploit and vivisect modern birds were headed in the wrong direction, a fact noted by a rising star of pterosaur paleontology last March:

Avian biomechanical parameters have often been applied to pterosaurs in such research but, due to considerable differences in avian and pterosaur anatomy, have lead to systematic errors interpreting pterosaur flight mechanics. Such assumptions have lead to assertions that giant pterosaurs were extremely lightweight to facilitate flight or, if more realistic masses are assumed, were flightless. Reappraisal of the proportions, scaling and morphology of giant pterosaur fossils suggests that bird and pterosaur wing structure, gross anatomy and launch kinematics are too different to be considered mechanically interchangeable. Conclusions assuming such interchangeability—including those indicating that giant pterosaurs were flightless—are found to be based on inaccurate and poorly supported assumptions of structural scaling and launch kinematics.

The take home point here -- the question the pterosaurs haunting my dreams have been trying to raise -- is, how efficacious is animal testing in paleontology anyway?

I've blogged before about the moral quandary I'm slowly approaching in my studies. I must confess to having set out upon this path with more than a little naivete. Paleontology appealed to me because it allowed me to study animals and evolution without having to hurt any living beings. When I found out this wasn't true, I began cultivating an interest in paelobotany that might still claim my future. For all my paleo-nerdiness and love of science, I am unwilling to harm nonhuman animals, even indirectly, in my pursuit of knowledge.

Still, reliance on modern animals is far less common in paleontology than it is in other life sciences, and I think that with some due diligence and activist pressure from within, the paleo community can and will do a better job of monitoring their sample sources. If I'm lucky, I may get to play a role in that one day.

The incompatibility of pterosaur and bird anatomies can help highlight the ethical point. Pterosaur researchers had become so enamored with birds (not that I blame them!) that they failed to see pterosaurs for who they really were. And this meant, not incidentally, that many modern birds went under the knife in those researchers' quest to crack the "mystery" of giant pterosaur flight.

We now know that those poor birds' sacrifice was in vain. Analogies with birds were taken too far, both scientifically and ethically. Pterosaurs were not dinosaurs, and that means they weren't bird-like, either. We can now add bird experimentation in pterosaur research to the long list of animal testing that was pointless, and arguably more cruel because of it.

I don't want to make too much hay out of it, though. As I've already written, many paleo labs use salvaged animal remains from ethically-clean sources, and absent any evidence to the contrary, I'm assuming this has been generally true of pterosaur research, as well. I'm still heart-broken, however, at the prospect that at least some birds used in that research over the years were the victims of commercial suppliers to whom the birds were mere commodities, not beautiful living things with something important to teach us. Again, if there is cruelty and blame to be assigned here, I'm inclined to place it on the suppliers, not the researchers.

The pterosaurs are calming down now. I think they're happy that I finally figured out what they were trying to say: "we are proof that animal testing is often pointless."

I love them now more than ever.

Creationism: Not Just For Christians!

2011-04-22T10:02:00.000-07:00

It's probably not a surprise to anyone that there are creationists in all three of the major monotheistic religions, though Jewish ones are hard to come by. Muslim creationists, not so much, especially in Turkey. But I, for one, was surprised recently to discover that the evil meme's tentacles have a reach much farther than I thought.

In a recent Facebook dispute/discussion, I was informed that someone named Michael Tsarion, a possessor of "ultimate truth," is (allegedly) a vegan. This, we were told, was a boon to the animal rights & vegan community, because he is a wise man. But after spending a few hours enthralled by Tsarion's woo, I had to conclude, "with friends like these..."

Tsarion appears to be a booming franchise (though it's hard for me to independently verify, as a Google search on him turns up mostly sympathetic or critical sites, not analytical ones), and sells the standard New Age mumbo-jumbo boiler plate. His videos are all over the web, and he talks a lot about the "truth" about Atlantis and the hidden meaning of ancient religious texts, 2012, etc. You know the drill. He works in aliens and genetic manipulation, too. That's where it gets interesting, because the guy, despite rejecting Christianity, is a full-fledged creationist, and apparently of the Young Earth variety.

Tsarion's book Atlantis, Alien Visitation and Genetic Manipulation, contains a bizarre narrative in which our solar system was colonized 50,000 years ago by two warring alien races. The first race, retreating from the second, used a fictional, (mostly) water-world called Tiamat between the orbit of Mars and Jupiter as a decoy, and then secretly settled on Earth. When their enemies arrived, they destroyed this water-world and its

vast saline waters entered into the Earth’s atmosphere causing the first of two massive prehistoric deluges and tribulations that mankind would experience. It is thought that the alien invaders took full advantage of this predicament and moved in to bring about colonization. They met no resistance from the disoriented and weakened inhabitants of the Earth who believed their visitors were powerful gods.

Take that, Judeo-Christian-Muslims! Tsarion sees your Great Flood, and raises you another one!

This, Tsarion seems to think, is the origin of Earth's oceans, or at least most of them. Too bad for him, the marine sedimentary record stretches back 3.8 billion years. And what's more, there's no geological evidence of a worldwide, catastrophic flood, let alone two of them.

He also thinks the remnants of this fictional planet between Mars and Jupiter became the asteroid belt. Bad news, Mike: the asteroids were never a planet to begin with. In fact, there's not even enough mass there to build a body the size of our moon.

Appendix B of his book is full of references from geology and evolution deniers, quote-mined references from legit scientists, and a bit of absolute bunk... just like his evil Christian opponents' works!

If this guy is a vegan, I sincerely hope he never opens his mouth about it, or tries to become a prominent figure in the AR-vegan community. We've got a hard enough time as it is gaining cultural legitimacy. Tsarion could, all by himself, destroy what little progress we've made with his ridiculous babble.

If you're in the mood for some high comedy reading and have a couple of hours to kill, though, check him out. Don't forget the popcorn.

Looking Ahead

2011-04-19T18:52:00.000-07:00

OK, I admit it. One of the reasons I deleted this blog was that I had frustrated myself with poor time management. Because of this, the blog kept getting de-prioritized, and my time between posts got progressively longer as the posts themselves became shorter. Those with any length at all were, to my eye, haphazard and poorly-sourced.

Well, enough of that. I've set myself a schedule. From now on, Friday will be blog day, barring important exceptions like final exams, field work, etc. So, once a week, I will post something new and (hopefully) substantial. During the rest of the week, I may log in to put up interesting links or pics from other sites, with brief commentary, but won't pressure myself into trying to say something profound about them.

Also, I had previously announced two main research projects, and begun one of them: The History Of Your Teeth; and the tentatively-titled Paleontology (Not) On Your Plate. The first, already begun (and soon to have its own page here), is pretty self-explanatory. The second was to examine the evolution and fossil record of common food animals, beginning with the beautiful chickens, turkeys, ducks and other exploited dinosaurs who don't get their due.

Thing is, though, I can't do both of them at the same time, given my academic obligations and time constraints. So, I leave it to you, dear readers: which series would you like to see completed first:

1) History Of Your Teeth; or
2) Paleontology (Not) On Your Plate?

If voting for number 2, I'm also open to a new and better title. The one I have just doesn't roll off the tongue.

A Rescued Theropod Named...

2011-04-19T17:13:00.000-07:00

...Rocco. I sponsor him at Animal Acres Farm Animal Sanctuary, and plan on going to meet him in person very soon.

You'll recall I adopted him around the holidays last year. You should sponsor an animal (or two!) at AA, as well. The good folks there could use all the help they can get. Follow the link on the side of this page.

Neighborhood Geology

2011-04-19T17:07:00.000-07:00

One of the benefits of living in Earthquake Country is that, every now and then, when you least expect it, you stumble across some amazing geology. I was out running in my new neighborhood today, and rounded a corner to discover this spectacular outcrop of recumbent folding:

It's hard to tell what kind of rock it is from a distance, but I'm determined to get closer, with hand-lens and rock-hammers in tow.There's a lot of history to be seen here!

TRUE Humane Hunting

2011-04-16T23:54:00.000-07:00

“Fossil hunting is by far the most fascinating of all sports. It has some danger, enough to give it zest and probably about as much as in the average modern engineered big-game hunt, and the danger is wholly to the hunter. It has uncertainty and excitement and all the thrills of gambling with none of its vicious features. The hunter never knows what his bag may be, perhaps nothing, perhaps a creature never before seen by human eyes. It requires knowledge, skill and some degree of hardihood. And its results are so much more important, more worthwhile, and more enduring than those of any other sport! The fossil hunter does not kill, he resurrects. And the result of this sport is to add to the sum of human pleasure and to the treasure of human knowledge.”

– George Gaylord Simpson, Attending Marvels, 1931

Fallback Food Fight, As Promised...

2011-04-16T23:40:00.000-07:00

Let it not be said that I fail to honor my word. Perhaps I took a bit longer than planned to respond to Jonathan Maxson's challenge, but I always intended to follow through. And now, I have.

You'll recall that Mr. Permavegan wrote to me seeking a "worthy opponent" to help him refine or dismiss his hypothesis that meat was a "fallback food of last resort" for our prehistoric ancestors. I boldly accepted the challenge...

...and then pulled a D.B. Cooper.

So, first, I offer my apologies to Jonathan, and to the rest of you, for this mean rock-tease. Though my disappearance was not intentional (in the sense that it was pre-meditated), its effect was the same regardless. I have no real defense, but a brief explanation may be in order: in short, I encountered serious time-management issues this semester, coupled with the grieving process over my Dad's death, both of which were stressful enough independently, but together were converging to be an emotional K-T Event for me. I decided, sometime in mid-January, that writing a regular blog was just too much on top of all this other stuff, and cynically deleted it, thinking it had done no good anyway.

But, I'm over that pity party now, rested, healthy again, and ready to maintain this blog in a more measured way than before (but that's for another post).

So, without further ado....

My critique of Maxson's hypothesis rests on three main points:

He seems to misunderstand, and thus misapplies, the concept of a fallback food; in doing so, he concedes the argument to his oppoents (though apparently none of them were smart enough to notice!);
He lacks precision when discussing our ancestry in the context of his argument (just like, it should be noted, most of his opponents); and,
He engages in the naturalistic fallacy (again, just like his opponents).

I elaborate on those points, thusly:

What Is A Fallback Food?
Maxson argues that humans (by which I presume he means H. sapiens)

are not adapted to a structural dependence on meat. The evidence is much more compelling that we inherited an immunological resistance to meat-related pathogenecity that allowed us to survive on meat as a fallback food during times when superior plant-foods were not available.

But, based on current understanding of human evolution, this formula is backwards. Meat would be what's called a "preferred food," and various plants would be "fallback food."

In anthropology, fallback foods are resources upon which primates depend for survival during times when preferred foods are scarce. Preferred foods are "high-quality" (that is, nutrient-dense) resources for which primates will temporarily abandon their fallback strategy when the opportunity presents itself, and for which they will take risks.

It might seem that preferred foods are more evolutionarily significant, given their caloric pay-off, but they're not. Because fallback foods are what a given primate population eats most of the time, they influence that population's evolutionary development far more than preferred foods do. As Marshall, et. al., (2009) summarized it:

Fallback foods are becoming increasingly invoked as key selective forces that determine masticatory and digestive anatomy, influence grouping and ranging behavior, and underlie fundamental evolutionary processes such as speciation, extinction, and adaptation.

Maxson is basically right that humans (H. sapiens?) have inherited a suite of characters developed over 70 million years of primate evolution, and that the primate adaptation to frugivory is the foundation of our anatomy and biology. But this doesn't mean that fruits, tubers and seeds were our preferred foods; quite the opposite, in fact. They were what "we" depended on most of the time for our daily survival, and thus they became the selective factors with the greatest influence on our dental and digestive anatomy.

By arguing that meat was a "fallback food of last resort" for our ancestors, Maxson is essentially saying that meat-eating made us human by shaping our anatomy in a unique way... precisely what his "livestock propagandist" opponents appear to be saying, too! I doubt this was his intention, however; he wants to argue that meat-eating wasn't terribly important to our evolution, and he'd be on much better footing if he reversed his categories and called meat a risky, preferred food... which is what most anthropologists think it was, anyway.

(It hasn't been lost on me -- nor should it be on you -- that none of Maxson's opponents appear to have called him to the mat on this point! More evidence that "paleo-dieters"/"livestock propagandists" know much less about evolution than they think they do!)

Who Is This "We"?
In a significant portion of his essay, Maxson refers to human ancestors and modern humans alike under the umbrella pronoun "we." While from an animal-rights perspective I applaud his inclusiveness, I'm afraid it's not precise enough for the purposes to which he wants to put it. When talking about what "we" are or are not adapted for, or what "our ancestors" evolved to do, one cannot simply speak so vaguely.

Which human species are Maxson referring to? The australopithecines? The paranthropus? H. heidelbergensis, believed to be the common ancestor of both our species and H. neanderthalensis?

It matters, because hominin species have developed in a wide range of habitats and climatic conditions across a large slice of geologic time, and have exploited a varied range of fallback food and preferred food strategies. If we aim to figure out precisely how important meat-eating was to the evolution of modern human anatomy, we have to speak with more precision. Specificity brings clarity, especially in scientific discussions.

There is a broad tendency for people to talk about all of these human species as though they are all equally relevant to the evolution of H. sapiens. Vegans and carnists alike are equally guilty on this score, each camp cherry-picking the traits or species that seem most suitable to their respective bias, often with little regard for the actual patterns and context of the fossil record.

Vegans, for instance, will highlight the apparent dependence of (some) australopithecines on roots and tubers that grew on Pleistocene savannahs, ignoring everything that happened in the following 2 million years.

Likewise, carnists will invoke, say, the heavy meat-dependence of H. neanderthalensis, with no regard to the fact that Neanderthals are not our ancestors. Or, they will point to chimpanzees hunting and killing small game, without explaining how such behavior has shaped chimp (let alone human) evolution.

This is insufficient in both cases, at least if our goal is to inform the debate with actual science.

Who Cares What Species X Ate?
Finally, Maxson seeks to argue that "a plant-based diet is most definitely the natural diet of Homo sapiens." I'm glad he didn't write, "veganism is most definitely the natural diet of Homo sapiens," because while the first statement might approach plausibility, the second one is flatly absurd.

Yes, you read that right. A vegan just wrote that veganism is not the natural human diet. And he'll now write that the "paleo-diet" isn't, either.

As a scientist(-in-training), I am skeptical that there is any such thing as a "natural human diet." True, our species possesses a suite of characters inherited from (largely) frugivorous primate ancestors. It's true, also, that our species has for its entire history hunted and killed other animals for food. Neither of these facts, however, (nor any of the many others that each "side" in this debate can muster) implies something about what's "natural" for us to eat.

I realize that Maxson hasn't forthrightly stated that veganism is our natural diet, but his whole argument seems to rest on that implication. As does, it should be noted again, the bulk of his opponents' arguments with regard to their particular diet ideology (i.e., "paleo"-dieters argue we should eat animals because our ancestors did).

The problem is that both lines of argument rest on the naturalistic fallacy. From the ethical perspective of modern humans in modern situations, what our prehistoric ancestors did is irrelevant. So what if australopithecines were mostly herbivorous? So what if Cro-Magnons hunted and ate bison? We are not living in their world or facing their challenges.

From a biological perspective, it's certainly true that humans have a fundamental need for specific nutrients. But that by itself doesn't mean we have a need for (let alone an obligation, either biological or ethical, to eat) specific nutrient sources. Neither meat nor vegetables possess magic powers, and we have come far enough technologically to make the question moot, anyway. There are supplements for everything.

Further, it's a mistake to assume (as both camps here often do) that because we have such a biological need, that need was somehow being met in our ancestors' daily diets. It's entirely likely that our ancestor species, like most others, passed on their genes by living just long enough to ensure their offspring survived to sexual maturity. That's good enough, as far as evolution is concerned. Natural selection doesn't care if you've met all your daily nutritional requirements; it just needs you to make sure your kids live long enough to fuck.

I'm dubious about all arguments from an appeal to nature, whether from vegans or carnists. Among vegans, it often seems to signal a reluctance to face the facts about our species. It's as though they think accepting H. sapiens' meat-eating and hunting past somehow weakens the moral argument for animal rights. I don't think it does, any more than the long history of human slavery weakens the moral argument against servitude. One does not need to deny the historical reality of slavery to argue that slavery is wrong. Same thing applies to animal-eating.

Veganism is an entirely modern philosophy, and there is nothing to wrong with that. Attempts to reverse-engineer it into our history and our evolution are doomed to failure, and only weaken our case in the long run when properly-skeptical listeners check our factual claims and find them wanting.

Vegans should, in my opinion, always engage non-vegans on moral and ethical grounds first, only resorting to "health" arguments when they're actually on our side.

Of course, the natural sciences can inform our ethics, but we should all have learned by now that biology is not destiny. Vegans argue that humans descend from a long, herbivorous ancestry, and that many of the traits of that ancestry are reflected in our anatomy. Carnists retort that cavemen met many of their nutritional needs by eating meat, and that meat-eating might have shaped some aspects of our physical evolution.

You know what? They're both right. Personally, I think neither side will ever win the debate over H. sapiens' "natural" diet, because no such thing exists. We might as well, someone once said, debate how many angels can dance on the head of a pin.

And from an animal-rights perspective (the basis of my personal commitment to veganism), it's a pointless argument, anyway. The primary goal of the vegan movement is -- or ought to be -- saving nonhuman animals from exploitation. I don't see how trying to prove veganism is "natural" helps that goal.

What Everyone Should Know About Paleontology

2011-04-12T20:46:00.000-07:00

I often forget that the basics of geology and paleontology are not common knowledge; thus, blanks in discussion don't get filled in where they should, and people have trouble connecting the dots.

Thankfully, the question "What Should Everyone Know About Paleontology" recently came up on the Dinosaur Mailing List, and Dr. Thomas R. Holtz, Jr., supplied a very comprehensive answer. Crurotarsi: The Forgotten Archosaurs has the full article.

It's henceforth required reading for this blog.

Son Of PaleoVeganology

2011-04-12T19:39:00.000-07:00

Quite rashly, I deleted this blog a few weeks ago, because I was feeling swamped and something had to give. But, I have reconsidered my actions, and decided I made a mistake.

Apologies to my readers. I will try to pick things back up in a few days. If you're still reading this, please spread the word.

Pistols At Dawn, Permavegan!

2011-01-18T14:13:00.000-08:00

Jonathan Maxson, author of the excellent blog The Permavegan, stopped by my Comments section a few weeks back, to offer up a gentlemanly challenge. By way of acceptance, I am re-posting his entire comment here, for the benefit of those who missed it the first time around.

Thank you, Geologizer, for a great blog. About two-thirds of the way through a long post I recently authored, under the article subheading "Fallback Food of Last Resort," I introduced my quick take on the argument that a plant-based diet is most definitely the natural diet of Homo sapiens.

I am looking for a worthy "opponent" to help me refine (or discard) my fallback food of last resort (FFLR) hypothesis in a leisurely and friendly cross-blog debate.

My ideal opponent is an insightful, independent, cutting-edge thinker in a field like paleoveganology who is favorably disposed toward vegan ethics but scientifically skeptical about vegan claims such as the FFLR. My ideal opponent (which is really too strong a word; open source peer review is much closer) will not be influenced one way or the other by my activism in the fields of energy descent, climate change, monetary reform, and degrowth, but will keep the discussion squarely focused on the scientific evidence for and against FFLR.

In addition to the FFLR article sub-section and my post on carbon isotope analysis of australopiths, I have read - but much too quickly - perhaps fifty articles and two hundred abstracts relating to this subject. I did all of this research in the spring of 2010, and wrote up a number of notes, the gist of which is that the expensive tissue hypothesis is extremely unlikely to support a meat-intensive diet as the driver of human brain evolution, but is entirely consistent with a carbohydrate-intensive diet. I have not been able to write up my FFLR hypothesis because I am working simultaneously across too many other more pressing research and advocacy fronts to maintain it as an independent line of critical inquiry. However, I think I could tackle it efficiently, effectively, and enjoyably through dialogue with a competent and intellectually gracious devil's advocate.

If this proposal interests you, please feel free to respond with a post on your own blog addressing however many holes in FFLR you would like to start with, and we can take it from there as our schedules allow.

Thanks again for a great blog, and regardless of what you decide about my proposal, I wish you all the best as you continue with your writing on PaleoVeganology.

And here is the full text of "Fallback Food Of Last Resort," for those who don't wish to read the entire long post he's referring to:

The underlying myth of the livestock propagandists - that it is in our biology to kill animals for food - is far from unassailable. The mere existence of meat consumption as a cultural trait, even from the very beginning of our technological experimentation, is not evidence that it confers a health benefit relative to a plant-based diet. Nor does it mean we need meat to survive when other, better foods are available. It is simply evidence that meat-eating was a dietary choice our ancestors took late in the evolution of our species. They created a meat-eating culture, and they passed it down to us, but we need to be very clear that it is a cultural inheritance, not a biological dependence - and it's certainly not an inheritance we're obligated to pass on.
Humans are not adapted to a structural dependence on meat. The evidence is much more compelling that we inherited an immunological resistance to meat-related pathogenecity that allowed us to survive on meat as a fallback food during times when superior plant-foods were not available. The revolution in our worldview now taking place is the exact opposite of the Man the Grass-Fed Locavore propaganda promoted by Lierre Keith, Simon Fairlie, and other emissaries of the Weston Price Foundation. The crux of our humanity is much more likely to be a set of veganic permaculture skills, defensive capabilities, empathic social intelligence, and a higher level of amylase in our saliva than any other primate before us. These adaptations, amplified with cooking technology, allowed our ancestors to feed their brains with copious amounts of nutrient-dense carbonhydrates from starchy tubers and rhizomes growing at the edges between woodland, savannah, meadow, and waterway.

We did not evolve hands and a bipedal structure to exhaust our precious energy chasing game. I believe we evolved these appendages to defend our kin-groups from attack by predators; to harvest tubers, berries, shoots, mushrooms, seeds, sprouts, nuts and plant-based materials of all kinds; and to sustain other rudimentary forms of human culture. We evolved as prey, not predator, and it is in our nature to flee or fight when attacked, but not to hunt animals for our food. For most of our evolution we avoided meat because of its intrinsic incompatibility with our physiology and its tremendous pathogenecity. But meat-scavenging in a time of scarcity most likely created the evolutionary bottleneck(s) through which our lineage developed sufficient immunological and digestive tolerance to this otherwise toxic substance. That doesn't mean it's an appropriate staple for a physiology built on a base of seventy million years of herbivorism. Meat and animal products are a fallback food of last resort.

This may sound like wild-eyed fantasizing to you, but as we work our way through all the ins and outs of this food fight, I believe it will prove a much more plausible read of the scientific literature than the Man the Grass-Fed Locavore meme propagated by the livestock industry.

I will post my responses to this challenge in the next few days. This post signals my acceptance of Permavegan's offer, on his terms. Stay tuned.

Deep Time & The Sanctity Of Death

2011-01-02T15:31:00.000-08:00

"Life," John Lennon once quipped, "is what happens while you're busy making plans." I had the truth of that witticism driven somberly home for me this holiday when, in the midst of revelry and blog-planning, I learned that my father has died.

Everyone puts their grief into a context. Here is mine. It's a eulogy that should have been given at my Dad's funeral, but that I hadn't thought through clearly at the time:

"I have not come to mourn, but to celebrate. My Dad has not simply died, nor has he 'passed away.' He has become my ancestor, and that is a wondrous thing to be.

Of course, I am deeply saddened by his death. It will be a long time before I can reconcile myself to a world without his consciousness in it. But my sadness is tempered by the knowledge that death is not a curse, a punishment or a negative. It is not something that's wrong with the universe. It's a natural thing, and yet much more profound than that.

Death, much more than life, is the root source of the universe's strength and diversity. Much more than life, it shapes us and molds us into who we are. Death is something to be honored.

Every one of us here today, and every other person who's ever lived -- indeed, every being that has ever lived, and every rock and every river and every star and planet and every drop of water in the universe today -- is made of elements forged in hearts of dying stars. The oxygen in our lungs, the calcium in our bones, the carbon in our DNA: all of them are the 13-billion-year-old offspring of stars that died in gargantuan explosions and scattered their mass across the universe. We are star-stuff, and without the deaths of the first generation of stars, nothing else could exist anywhere.

Mountains die, too. Over millions of years, they erode down to bedrock, their sediments blending with the detritus of dead organisms to become life-giving soil.

And in that soil are nurtured the mightiest trees, held tall and strong by their dead parts: bark and wood.

When we were just a ball of cells in the womb, our ability to grow heads and hands and arms and legs depended on certain fetal cells dying at the right time, in the right way. Without that programmed cell death, we -- and all other life -- would remain just balls of cells, forever.

When our brains are developing, millions of neuron cells die and get replaced by new synaptic pathways. Without that neuron death, we'd be unable to think, or feel.

And then there's cancer, which has become for many of us the very symbol of death's ravages. Yet, cancer is actually caused by the absence of death. When certain cells fail to die, they become cysts and tumors that ravage their neighbors, sucking up resources and refusing to die. Within our bodies, death is the enemy of cancer.

Knowing all this, I cannot be someone who sees death as a curse. Know all this, I have come to see death as a creative force at all levels of existence, from the most ancient of stars to the tiniest of cells. Death, to me, is a sacred thing, as sacred as life. Death makes life strong. Death is holy.

I have my Dad to thank for this insight. It was he who sat me down to watch Carl Sagan's Cosmos every week when I was a kid. That's where I first learned that I am star-stuff, and the lesson stuck with me.

Thanks, Dad.

That is why I have come to honor Dad's death, not mourn it. For Dad has joined the ranks of the stars and the mountains and the countless species who died before him, who recycled their essence into the life we have today. He has become an ancestor, and that is the most honorable accomplishment of all.

Why should I mourn that?

Skepticism Leads To Animal Rights

2010-12-21T03:23:00.000-08:00

Or so says The Pythagorean Crank. And I must confess, I agree with him 100 percent.

I used to shy away from animal rights as a justification for my veganism, too. And while there are some good non-AR arguments for veganism, none of them seem as robust to me as the animal rights position. Its logic has been inescapable to me for as long as I've been thinking critically. Indeed, it was my skepticism that led me to veganism in the first place. I have a low tolerance for sales-pitches (even though I'm told I'm good at giving them), and there are few pitchmen more vigorous than the meat and dairy industries.

Whenever I'm challenged to defend AR, I simply say, "it's just plain mean to do this to animals when there's no good reason." I find that almost always makes people think and nod their agreement, and I know of at least one person who made the plunge themselves after talking with me. I never once said anything remotely hippy, and I never will.

I'd like to see more vegans do it that way.

Save Yourself Mammal!

2010-12-20T23:20:00.000-08:00

The perfect holiday gift for the dino-geek in your family.

Catching Up

2010-12-20T23:17:00.000-08:00

We've got a lot of it to do here. First up, I will try to complete at least one more installment of my History Of Your Teeth series. I'll introduce you to my new dinosaur friend, living out his now cruelty-free days at Animal Acres, and use that as a launching point into a new series about the evolution of modern food animals, tentatively titled "Paleontology (Not) On Your Plate."

But first, a word about my goals with this blog. Recently, there seems to have been a wave of visitors convinced that I am trying to build an evolutionary case for Man The Vegan. Of course, anyone who reads regularly -- and thank you both ;-) -- knows that's not the case, but it does raise the opportunity for some clarification.

PaleoVeganology does not seek to argue that veganism is H. sapiens' "natural" diet, nor does it accept the proposition that the so-called "paleo" diet is, either. This blog is rooted in skepticism, meaning that I doubt there is any such thing as a "natural" human diet. Evolution didn't simply design the world to suit our intestines, and many completely natural things are more dangerous to us than any synthetic food could ever be (after all, synthetic foods can't evolve defenses). Paleontology can conclusively establish the fact hominids ate meat, at times a lot of it. But that doesn't really tell us something we didn't already know, and it's hardly enough to make grand claims or establish umbrella hypotheses about.

The goal of this blog is to inform the vegan/animal rights movement with a paleontological perspective, and help us all understand the geo-biotic context that makes us neighbors, not rulers, of other species. Along the way, I'm sure, I will continue to encounter or be challenged by ghouls* of various varieties, but at this point, I am not primarily writing for them.

*Ghouls are beings who eat the flesh of corpses. Has a much nicer ring to it than "carnist," dontcha think?

I'm Baaaacccckkkkk!

2010-12-18T10:45:00.001-08:00

Just wanted to let you, my dear readers, know that I haven't forgotten or abandoned Paleoveganology. Over the next few weeks, I'll be getting a lot done here, now that I am not burdened by final exams and such.

Speaking of which, I did great. All A's!

The Origin Of C4 Grass

2010-11-28T10:55:00.000-08:00

No, it's not a reference to explosive marijuana.

New analysis of fossilized pollen reveals that some grass species evolved C4 photosynthesis about 14 million years earlier than previously thought from geological evidence. This may require a total rethink of the role of CO2 depletion in the evolution of modern grasses.

Dry stuff (pun intended... think about it), but the most fascinating paleo-read I came across this month, outside of my formal academic studies.

Confession Of A Failed Omnivore

2010-11-28T10:21:00.000-08:00

There's been something of trend lately, of former vegans publicly (and rather drama-queenishly) renouncing their veggie ways and embracing a new role as "ethical omnivores." I won't bother linking to any of these pedantic blogs, as I'm sure many of you are already aware of the fad.

However, did you know that there are former omnivores doing the same thing in the other direction? A bit tongue-in-cheek, here's a brilliant (and satirical) confessional from a self-professed failed omnivore.

And to think, I was gonna write one along the lines of "how paleontology made me vegan," aimed right at the heart of this trend. I might still do it, but Marla's blog does a fantastic job of both truth-speaking and parodying this recent fad of self-indulgent nonsense.

A Dinosaur Of My Very Own

2010-11-28T09:59:00.000-08:00

Now that I have more of it to spare than before, I've put my money where my keyboard is and become the sponsor/"parent" of a rescued turkey at Animal Acres Farm Animal Sanctuary. I get to name the turkey in question, and this has put me in kind of a pickle. Since I don't know the gender of my turkey yet, I'm trying to think of a name that can go either way.

Right now, I'm torn between Manny Raptor (which can be modified to "Mandy" if necessary), or simply Jive.

I'll be receiving a photo of my new turkey friend, which I'll post here when it arrives. If it's small enough, I may carry it my wallet and show it around as my pet dinosaur.

In the spirit of the holidays, you should sponsor an animal there, too. Especially if you're from the L.A. area.

We Need More Vegans Like This

2010-11-16T14:28:00.000-08:00

Vegan Skeptic does an excellent debunking of the recent meme that veg*nism is worse for the environment than meat-eating.

I like Infinity's blog not only for work like this, but also because of its focus on "promot(ing) reason and skepticism in the animal rights community." There's a lot of mystical, pseudo- and anti-science, mumbo-jumbo in our movement, and I am often frustrated by it, especially since I think the weight of reason and science support a vegan lifestyle for most people living in the modern world.

I'm glad we have smart cookies like this fellow to help us steer the Good Ship Vegan towards saner waters. I just wish more of the crew would pay attention.

In Search Of A Specialty

2010-11-16T14:04:00.000-08:00

I'm trying to narrow the focus of my paleo-education, in the interests of both long-term planning and animal rights. That is to say, I'm trying to develop a planned specialty that will allow me to pursue my scientific passion while minimizing (or, hopefully, eliminating completely!) my impact on other living animals. To remain within the paleo realm, there are four broad specializations to choose from:

1) Vertebrate Paleontology -- top-dog in terms of funding and popularity. This is where you find dinosaurs, mammoths and almost all of the other critters the general public thinks of when they hear the word "paleontology." It's comfortable, familiar and more than a little nostalgia-ridden (at least for me). And, I admit, I am still drawn to vert-paleo because of an abiding interest in several questions: the Pleistocene megafaunal extinction, early- to mid-Triassic crocodile diversity, the relationship between pterosaurs' decline and birds' success in their wake, the Permian protomammals (which reminds me, wasn't I doing a series on teeth?...), and of course, the story of us H. sapiens.

But the problem with vert-paleo, from an animal rights perspective, is that it relies a great deal on comparative anatomy with currently-living species. A lot of labs and researchers make an effort to obtain fresh remains only from scavenged sources, but even still, there are a lot of links in the chain to be accounted for, and the lab-animal supply industry is notoriously corrupt and under-regulated. So, going the vert-paleo path would require a commitment to ethical watch-doggery. I'm not against that at all, and the idea of becoming (in)famous as the guy who helps clean up vert-paleo in this sphere appeals to me. But, I can do that regardless of my specialty field, so it doesn't tip the scales too much in one direction or the other.

2) Invertebrate Paleontology -- The horror fan in me loves this one. Not only does it cover the evolution of modern creepy-crawlies like spiders, scorpions, squids and worms, but also bizarre things like the five-eyed Opabinia and my favorite trilobite, the frightening Dicranurus monstrosus. Who needs space travel to find fascinating and creepy alien life when there's a whole other ecosystem of high weirdness like this right here on Earth?

But again, the problem here is a reliance on exploitation of modern species. And while not many people get worked up about the treatment of bugs and worms, it's still enough to give me pause. No one who's watched a lobster try to escape a pot of boiling water can doubt that invertebrates have a survival instinct, even if the question of whether they feel pain remains open. So, again, I'm faced with the same issue as vert-paleo, with the exception that I'd probably find a lot more resistance to humane treatment efforts for bugs than I would for vertebrates.

3) Paleobotany -- Every few months, I lean heavily back in this direction. People need to be turned on more to plants. The study of their evolution is essential to understanding modern problems of climate change and species diversity, and from a paleontological perspective, it gives us a whole different lens through which to view the question of mass extinction (since plant evolution doesn't appear to follow the same pattern of extinction and recovery as animal life does). Plus, there's appeal for the horror-fan in me here, too: carnivorous plant evolution is not well-studied, and that leaves a lot of room for a lot of exciting and interesting research (and even it wouldn't involve harming animals, since most carnivorous plant species thrive just fine without animal prey).

4) Micropaleontology -- Studies microorganisms. Not as boring as it sounds, and like paleobotany, highly-useful in the study of global warming. Also, like invert-paleo, fully of bizarre beauty -- check out some image galleries of radiolarian and coccolithophore fossils if you don't believe me.

As I continue my traverse through the academic world, I'll make this blog a sounding-post for the further development of these ideas, and hopefull settle on a specialty that fulfills both my main concerns.

Wish me luck!

Another Dinosaur Dodges Extinction...

2010-11-08T15:55:00.000-08:00

...thanks to the courage and compassion of one teenaged girl.

What's more disturbing is the insidious way this snuck into a curriculum where students are given a choice whether to dissect in science class. It's almost as though there's someone out there demanding that animal cruelty be a required part of education.

I resolve to work harder on starting my Backyard Dinosaur campaign. Kids with heart need to know there are dinosaurs waiting to be saved every day.