Friday, October 16, 2009
A problem with Ardipithicus ramidus
Ardipithicus ramidus, the 4.4 million year old fossil hominid, has been in the news lately. She's caused quite a stir because it turns out that she was bipedal. No one expected that from a 4.4 million year old hominid. The thinking was that as far back as that, all of our precursors would still be knuckle-walkers. But Ardi has surprised everyone.
My problem is not with Ardi's bipedality. It's not even with Ardi herself. It's with some of the hypotheses being thrown around about her bipedality coupled with the relatively small canine size in both the males and females of the species.
I watched a discovery channel show about Ardi, her discovery, the analyzation of the remains, and results of the research thus far. A big deal was made about the small canine size (in both males and females) and the bipedality. These are two very strange traits - bipedality in mammals is almost uniquely found in the hominid/human family tree. And, why in the world would evolution favor the males giving up their huge canines - used for defense and in battling over females? The focus was on trying to account for the circumstances which would drive the evolutionary selection of these two traits together.
And what reason did the men come up with? It must have been because the males of the species suddenly could provide more for the females, who were more receptive (sexually) to them because the males could now walk upright and carry food that they had gathered back to the females.
That's what I have a problem with.
Hasn't it been Man The Hunter up until now who drove the evolution of the species while the females quietly gathered in the background? And now that it looks like gathering might have been the impetus for bipedality, suddenly it's the males who are doing it? While the females are doing what, exactly? Sitting around back at camp waiting for the males to come back loaded down with food so that they can open their legs for them?
A bit one-sided, don't you think?
How about this scenario: Ardipethecus ramidus was a hominid, the group structure of which was not run by male dominance, but instead was a matriarchy, similar to Pan paniscus, or today's Bonobos - a species of chimpanzee whose social structure is run by the females. Bonobos are more comfortable with bipedal motion than their cousins, Pan troglodytes (the chimps that you may be more familiar with). And Bonobo canines are smaller and less sexually dimorphic than those of regular chimps. In the Bonobos it is the female who chooses the male, unlike their cousins, P. troglodytes, the males of which use their large canines to fight for the females, and are often aggressive toward the females themselves.
Lets put the female hominid back in her role as gatherer. It is not an unimportant role, although perhaps it has been made to seem so only because it's the females who have been doing it. Gathering is what has sustained the hominid population throughout these millenia, while the male role of hunting (or, more likely early on, scavenging rotting carcasses for putrid meat) has been important, but not as sustaining. In fact, let's look at this scenario and see if half of the population feels left out somehow:
The female hominid, by walking upright as she gathers, and is able to both hold her infant and the food she is gathering , is able to go farther afield and return with more food, enabling her to share with the group. As the brain size of the hominids evolve and grow larger - no doubt due to the female's need to recognize useful and harmful plants, insects, and small animals, and to be able to to make the tools needed to dig and cut, and then to mash and chop, and to fashion things such as baskets to carry her foragings in - birth becomes more difficult because of the growing head size of the infants and the increasing difficulty of the head fitting through the birth canal. The need for help in childbirth drives group dynamics further, with women needing other women to help them. Peace and goodwill among group members, especially the women, drives group cooperation and selects against the aggressor.
Anything missing there? Well, if you are male, you now know how we women have felt every time we've read or heard about Man The Hunter.
I say we all grow up and start to look at human evolution from both sides of the story, and stop with this nonsense of attributing evolution-driving behavior only to the males of the species.