Martín Cagliari has uploaded at his most interesting blog Mundo Neandertal, the full documentary of Discovery Channel on the Ardipithecus Ramidus. A must view (while the blog is in Spanish, the film is still only available in English).
I was watching it yesterday and is most educative, specially for the amateur with just a side interest in ancient hominins, as is my case. But, as always they have to outline a theory, a Christian-sounding one, of course.
So I was not too persuaded that the two most surprising features of aunt Ardi and her kin, the grasping but bipedal feet and the very short and blunt canines responded too well to the theory suggested at Discovery Channel. They argue that this means two things: bipedalism in forest area (this last ratified by botanical and zoological research of the sediments - excellent job with that too) and lack of the kind of male competition we see among chimps for group dominance and hence reproductive advantage (they talk about controlling females but it's in fact more as I describe it here, as chimps are polyamorous, even if in a hierarchical manner).
So far sounds good. But the hypothesis launched is that these new bipedal males with low aggresivity responded to a new kind of bond (couple) sort of reproductive economy, in which the males could go farther looking for "quality food" (whatever that means) and carry it on their backs sounded kind of implausible and too moralist to be real. I was not persuaded.
As it happens often checking with your pillow helps to clarify thoughts and when I woke up I came with fresh ideas: they had been all the time ignoring bonobos!
Bonobos have relatively large canines but are much more bipedal than chimps, ability that they use to carry things around or just to walk, either on ground or on branches (someone pointed out recently too that even gibbons, the most distant ape, are sort of arboreal bipedal animals, that arboreal bipedalism is not that rare among our kin). Bonobo males also do not compete for the females (so their canines may well be somewhat redundant) but that is not because they live in couples and males have any enhanced role looking for food in far away places but because they are even more polyamorous than chimpanzees but females tend to lead the groups up to a point.
And when you look at Ardi after considering the bonobos, she looks very much like one in fact, right? In fact it is then when she stops looking like some sort of ape-ish chimera and starts making sense. At least for me.
Bonobos are more closely related to chimpanzees than to us but they share with us some traits that chimpanzees do not: they have a clear sense of empathy and compassion and the females are sexually available all the time, not just when ovulating. This allows them to have much more cohesive and horizontal societies, where males do not need anymore to compete for females' favors.
As I said before, they are also more bipedal than regular chimpanzees. They look like a much better comparison than regular chimpanzees for our evolution, at least in many aspects.
So my hypothesis is that Ardi and her kin were to some extent like bonobos in the social aspect. What do you think?