Hauries d´instal.lar el plug-in del flash... Descarregar plug-in de Flash




Disminuir Aumentar

Did the first bipedal hominids live in the savannah or the forest?

Last year, a team of scientists announced that Ardi, a pre-human fossils dating back 4.4 million years ago, had lived in a wooded area, an idea that was revolutionary because it contradicted previous theories. However, according to new findings from another team of scientists who examined the exact same data, the environment of the first bipedal primates was more likely a savannah.

Staff | 28 may 2010

In 2009, a team from the University of California at Berkeley in the U.S. published in the journal Science data suggesting that the hominids of the species Ardipithecus ramidus, to which the Ardi fossil belongs, had lived in the woods of Africa. But recently another study published in the same magazine and based on the very same data contradicts this theory.

“Our team reviewed the data published by White and his colleagues last October [2009] and found that their data does not support this conclusion,” said Naomi Levin, co-author of the new study, adding that the data indicated the opposite, that Ardipithecus ramidus lived in a savannah composed of mostly herbs and low-lying plants.

The environment in which these pre-humans lived is important to understand their evolution. The call of the savannah theory says that the expansion of this type of terrain was the reason these early hominids left the trees and began walking upright. The theory of life in a wooded setting, however, would require finding a new explanation for the developmental changes.

“If the habitat of Ardipithecus ramidus were savannahs where grass made up 60% of the biomass,” says Levin, “we can not rule out the possibility that the open environment play an important role in human origins and, in particular, the origin of bipedal walking.” He concludes: “Neither the public nor the scientific community should accept an exclusively forest habitat for Ardipithecus ramidus and the origin of bipedal walking because the data does not support it.”

The authors of the research in 2009 have already responded in another article, defending the methodology and validity of their analysis and indicating that the area where the Ardipithecus ramidus lived was very diverse and that it is wrong to generalize about a single type of environment.


Global Global Global Global