Today.Az » Weird / Interesting » Early man walked upright 2 million years earlier than we thought, says new analysis
22 July 2011 [12:16] - Today.Az
A lot of the debate about when modern humans became modern humans has to do with the head--when our brains evolved into the functional equivalent of that of modern mankind. But while that particular argument continues, a team of UK researchers using a new kind of statistical technique have analyzed ancient footprints at a site in Tanzania and found that if our feet are allowed to tell the tale, our early ancestors were becoming human-like as much as two million years earlier than we previously thought.
The study relies on eleven well-preserved footprints at the Laetoli site in Tanaznia that the researchers subjected to a new statistical technique derived from methods used in functional brain imaging. Using this technique, they created 3-D average of the 11 prints there, comparing them with data obtained from the study of modern humans and living great apes.
The researchers also used computer simulations to model a variety of
gaits--and the footprints they would have produced--for the likely maker
of the Laetoli prints, a species known as Australopithecus afarensis.
It was previously thought that this ancestor walked crouched over,
putting pressure on the side of the foot and pushing off from the
middle, like a modern ape.
Instead, they found through their simulations and the comparisons enabled by their 3-D statistical analysis that Australopithecus afarensis
very likely walked upright in a bipedal manner, more like modern humans
than previous studies suggested. Most previous work in the field
suggests that the upright, bipedal gait didn’t emerge in human ancestors
until about 1.9 million years ago, in early Homo. The Laetoli tracks
date to about 3.7 million years, effectively doubling the amount of time
that early human-like species may have walked upright.
That, of course, paints a drastically different picture of early
human history. It was humans’ ancestors’ ability to leave the trees and
walk and/or run over long distances that enabled humans to eventually
expand out of Africa and populate the world. If the Laetoli analysis is
correct, our ancestors were stepping out with a very modern foot
function far earlier than we thought.
/Popular Science/
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