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I am a politically-progressive, ethically-herbivorous anthropoid pursuing a paleontology education in the Los Angeles Basin. I am largely nocturnal, have rarely been photographed, and cannot thrive in captivity.

27 June 2011

Richard Dawkins Interviews Peter Singer

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.

17 June 2011

Round-up of Paleo Links

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

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. :)

11 June 2011

Empathy & Evolution: Did Loving Animals Make Us Human?

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.

04 June 2011

The Vocabulary Of Deep Time

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.