Anthropology.net

Bipedalism has graced our blog several times before, but we’ve mostly stuck to using comparative anatomy to explain the how’s and why’s to our unique way of movement. There’s new research coming from the Kennedy Krieger Institute that gives us a window into the adaptations and specific requirements the brain has made to accommodate bipedalism.

Specifically, after subjugating people to a whole lot of different experiments on treadmills with fancy infared computerized tracking, Amy Bastian observed that people can learn and,

“store different walking patterns for forward versus backward walking simultaneously, with no interference between the two, revealing that separate brain systems control the two directions of walking….”

This lead her to conclude that,

“there are separate adaptable networks controlling each leg and there are also separate networks controlling leg movements, e.g., forward or backward walking. These findings are contrary to the currently accepted theory that leg movements and adaptations are directed by a single control circuit in the brain.”

Her work is published in Nature Neuroscience, and I’ll forewarn you that this paper doesn’t have an anthropological scope as much as it has a clinical, rehabilitation one. Bastian aims to use this research to help people recover from strokes, hemispherectomies, and other forms of brain damage. But how this research supplements physical anthropology is pretty remarkable.

This paper gives us examples of how a pattern of pattern of changes in independent neural controllers for left and right legs can be rewired. That tells us the human brain is very modular and malleable. I feel that being able to reroute the neural networks involved in controlling movement is testament to the adaptive capacity of the brain. And I wonder if similar studies can be done with chimps, considering they have been working out on treadmills recently? I wonder how hardwired other primates are to their form of motility?

I hate to be bugging you with these half-assed side notes, but the PNAS paper that I’ve been swooning over the last couple of days is now out.

Here are the good bits: Dental evidence on the hominin dispersals during the Pleistocene,

“A common assumption in the evolutionary scenario of the first Eurasian hominin populations is that they all had an African origin. This assumption also seems to apply for the Early and Middle Pleistocene populations, whose presence in Europe has been largely explained by a discontinuous flow of African emigrant waves. Only recently, some voices have speculated about the possibility of Asia being a center of speciation. However, no hard evidence has been presented to support this hypothesis. We present evidence from the most complete and up-to-date analysis of the hominin permanent dentition from Africa and Eurasia. The results show important morphological differences between the hominins found in both continents during the Pleistocene, suggesting that their evolutionary courses were relatively independent. We propose that the genetic impact of Asia in the colonization of Europe during the Early and Middle Pleistocene was stronger than that of Africa.”

You’d think this would be good news to me. But it is actually really unfortunate for me, because my school’s library hasn’t updated access to this hot off the press paper, so I can’t download the full text just yet. Unless someone wants to graciously email it to me. I’ll be very grateful if you do, and will read and review it thoroughly plus share some of the good photos up here. Nevermind, I got it, and am reading it right now!

Since I’ve expressed interest in the drama that is unfolding about Lucy’s tour, I got passed a link to a Guardian article which writes on the topic and has a very poignant quote criticism from Louise Leakey,

“If [Lucy] has to be displayed it should only be in Ethiopia, [so] that the country draws some benefit from it.”

Guys, Louise gets it.

Ethiopia will benefit very little from the tour.

It really bugs me that all the press is toting phrases that lending out Lucy will generate money for musueum building in Ethiopia, as if the US museums are doing Ethiopia a favor… When really the case is that the museums in the US will be raking in the cash, and Ethiopia will be risking one of the most important hominid fossils out there.

So to say that I see the this move by the ‘hosting’ museums as hegemonic, is an understatement.