Pre-humans living in East Africa 4.4 million years ago inhabited savannas -- grassy plains dotted with trees and shrubs -- according to a team of researchers that includes earth science Naomi Levin of The Johns Hopkins University's Krieger School of Arts and Sciences.
This conclusion is at odds with a theory which holds that these early beings lived in a mostly forested environment put forth by prominent University of California at Berkeley researcher Tim D. White and his team in a 2009 issue of the journal Science.
"Our team examined the data published by White and his colleagues last October and found that their data does not support their conclusion that Ardipithecus ramidus lived exclusively in woodlands and forest patches," said Levin, whose team published a commentary on the matter in today's issue of Science. "The White team's papers stress the wooded nature of A. ramidus's environment and say specifically that Ardi did not live in a savanna. Yet, the actual data they present are consistent with exactly that: a savanna environment with a mix of grasses and trees."
This criticism is important because the claim that the 4.4 million-year-old fossil nicknamed "Ardi" lived in woodlands and forest patches was used as an argument against a longstanding theory of human evolution known as the "savanna hypothesis." According to that premise, the expansion of savannas grassy plains dotted with trees and shrubs prompted our ape-like forebears to descend from trees and begin walking upright to find food more efficiently, or to reach other trees for resources or shelter.
Levin, an assistant professor of earth and planetary sciences at Johns Hopkins, was part of a team of eight geologists and anthropologists from seven universities led by Thure E. Cerling of the University of Utah. They used the White team's own data to draw very different conclusion about the environment inhabited by Ardi, an omnivorous, a
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Johns Hopkins University