Jawbone Fragment Suggests Earlier Evolution

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Archeologists think they have uncovered a piece of a jawbone which indicates humans might have evolved hundreds of years before scientists previously believed. Paleoanthropology graduate student Chalachew Seyoum discovered the jawbone fragment in Ethiopia in January 2013.

The findings from the study of the jawbone were published on Wednesday in the journal Science.

What the jawbone suggests

According to Fox News, scientists believe the jawbone dates to 2.8 million years ago to a time when the Homo genus of humans supposedly split off from its alleged ancestors, which are more ape-like. The fossil skeleton archeologists refer to as Lucy belongs to this group, which is called the Australopithecus afarensis genus. Lucy was discovered in 1974.

The University of Arizona has been working at the site where the jawbone was found for many years, searching for fossils from the period during which the new jawbone is believed to belong to. The fragment has five teeth and was found in pieces by Seyoum when he spotted a tooth sticking out of the ground while he was looking for fossils in the area.

Details on the jawbone

Scientists saw the jawbone is that of an adult and features a chin that is primitive in shape plus traits they reportedly discovered in Homo fossils from later time periods. For example, researchers said the teeth are thinner than Lucy’s teeth.

One of the authors of the paper on the findings about the jawbone said they don’t know whether the fossil is from one of the Home species they already knew about or whether it represents a new species of the genus. Because of the combination of features found in Lucy’s skeleton and traits that are different, scientists believe that the jawbone belongs to a Homo species that evolved from Lucy’s species instead of one that’s just related to her.

John Noble Wilford of The New York Times reports that scientists do think the jawbone belongs to a species that lived “only” 200,000 years after the last evidence of Lucy’s species was found.


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