The Human Condition? Here’s Ardi! October 2, 2009Posted by Nina Rosenstand in Current Events, Nina Rosenstand's Posts, Science.
Tags: Ardi, Ardipithecus ramidus, Bonobos, chimpanzees, Darwin, evolutionary psychology, Gen Suwa, hominim, Merleau-Ponty, Owen Lovejoy, Tim White, Yohannes Haile-Selassie
This is a good day for those of us who like to hear, and tell, stories of Human Origins: The current story in the scientific world has been told for a while now, ever since Don Johanson found Lucy, the Australopithecus afarensis, in Hadar, East Africa in 1974: We are the children of small-brained, upright-walking primates who lived some 3 million years ago—primates with insignificant canine teeth, and almost-human hands with opposable thumbs. A creature living on the savannah, enforcing the perception that it was the loss of woodlands that made our early ancestors get up on two legs and look around.
But now we have a brand new chapter in our Story of Origin. Ardi is being introduced to the world, in today’s issue of Science Magazine and all over the newsmedia: Ardipithecus ramidus, a new ancestor (perhaps), at least another traveler on the road that lead to Homo sapiens. The painstaking assembly and interpretation of Ardi’s fractured bones (skull, teeth, pelvis, hands, feet) took 17 years, but now the researchers, including Gen Suwa, Tim White, Yohannes Haile-Selassie, C. Owen Lovejoy and others, have made their findings public. Ardi’s species predates Lucy by more than a million years, and it lived not far from that very same region. You can explore the details yourself if you are so inclined; personally, I am so excited that I can barely contain myself—this is the story I have been waiting for ever since the news of Lucy broke. What came before Lucy? Since 1974 we have known that the previous picture of early hominids as knuckle-walking, big-brained apes was wrong. We didn’t first develop the big brain, and then get up and walk. It was the other way around. But how far back in time did we diverge from the apes, and when did our hands leave the ground for good? We know that there were medium-sized monkey-type creatures dating back some 8 million years, and even dating back to the first early mammals, 60 million years ago, there were little mouse-sized mammals with some primate characteristics. But where the question gets interesting for most of us who are not paleontologists is, when did we start out on the road to becoming “Human”?
Of course this is one of the primary reasons why Darwin’s theory (The Descent of Man, 1871) met with such massive resistance which can still be felt whenever the debate swings in the direction of Creationism and Intelligent Design: Did we descend from chimpanzees? The Darwinist answer has, usually, been No, not exactly: We and the apes we know today descended from a common ape-like ancestor—we just had to look around for a “missing link” that could show us the intermediary version. Since then, the entire concept of a “missing link” has been discredited: Evolution doesn’t work that way—we don’t have links in a straight chain, but rather a multitude of branches that arise and die out, with some branches ending up being more successful than others. And besides, so few fossils are ever found that it would be astonishing to find an exact Happy-Medium form in-between two distinct species. Well, perhaps that’s what we have now. While Ardi is not a “missing link” (because we should stop using that terminology), she is so old that she represents a hominid (or hominim which is the new and more exact term) who is not even as “human” as Lucy who was truly not very human except for her manner of walking, and her hands. So is she more like an ape? And this is where the surprise comes in: Not really, even if her feet look like ape feet. If ever we humans were ape-like, it must be even further back in time, because Ardi seems to have (1) been upright, judging from the position of her head and pelvis, and (2) had smaller canine teeth than apes. Furthermore, this is the end of the fantasy that we evolved bipedalism on the savannah: Ardi lived in and among the trees, judging from other fossil finds in the area! But even so, she was already upright and bipedal at least some of the time. So was she Lucy’s ancestor? They don’t know yet for certain, but there’s a good chance that her species gave rise to Lucy’s species. And if that is the case, then she is also our ancestor. And she was not typically ape-like. Now that has got to please those who have a problem with the notion that we are “descendants of apes,” but that would be a premature celebration—it doesn’t mean we are not related to primates, it just means that some typical ape-like features were lost in the human line much earlier that we thought, and perhaps the human line never had them, such as chimp-style knuckle-walking. And the chimps and the Bonobos are still our closest living cousins on the planet. That hasn’t changed.
Now all this is factual as well as interpretative science. Why am I so excited? For one thing, I’ve always been fascinated by paleoanthropology. But more importantly for a philosopher, I have also for many years thought that our human origin is at least to some degree a determinant for our “human condition.” That’s what today is known as evolutionary psychology, but in more philosophical terms it means that our physical interface with the world (to borrow an expression from Merleau-Ponty) is an integral part of who we are, and how we interact with the world. Our Lebenswelt includes our physical being, and our physical being has an evolutionary history. If there’s anything that unites us as human beings, aside from our DNA, across the lines of politics, religion, race, gender, and so forth, it is this common history, the physical triggers that become the emotional and cognitive triggers. This is not to say that I discount the existence of “free will,” whatever that is—but our immense array of mental choices and possibilities is grounded in our physical abilities, limitations, and history.
So what can Ardi tell us, if the scientists are right? (1) We were upright, in the trees, long before we had the brains to make plans what to do with our freed-up hands, and comfortable being face-to-face with each other, close and personal, as well as probably capable of identifying each other at a distance; (2) we did not have massive canine teeth, meaning that the males probably didn’t fight over the females, meaning that we are perhaps looking at pair bonding and a semblance of gender cooperation (if not downright gender equality) dating back 4 million years—much more like the Bonobos than the Chimps, by the way. Does this mean that we were non-aggressive creatures, food for the predators rather than predators ourselves? Some of us would probably like to think so, but we can’t make that assumption. Look at Ardi’s eyes: Perfect stereoscopic vision, looking forward. Those are the eyes of a hunter, at least potentially, perhaps part-time if not full-time—opportunistic, like chimps. Besides, Ardi was omnivorous, like we are—she was not a vegetarian. The “killer ape” theory probably shouldn’t be declared totally dead yet.
In addition, National Geographic Magazine comes out with this spin: Why did we start walking upright? What can you do with free hands? Some of us would immediately say, You can hunt. But others would add, And you can gather. And bring what you have gathered to—your mate. Or the one you want to become your mate. Jamie Shreeve suggests just that scenario: We began embarking on the road to humanity by realizing that there was a sexual advantage to being able to bring food to one’s potential partner, in our freed-up grasping hands. And the upright female has another advantage: When she’s in estrus (heat) it doesn’t show. Which, according to Shreeve, would mean that she could string along the food-bringing male, even when she wasn’t ovulating, and even play around if she was so inclined. Now that opens up new vistas for the pair-bonding theory…