By Tesfa Mogessie
ADDIS ABABA
Scientists who recently unearthed a 2.8-million-year-old Jawbone in Ethiopia said Thursday that the discovery would significantly add to knowledge of human evolution.
They said at a press briefing in Addis Ababa that a fossilized lower jawbone found in the Ledi-Geraru research area of the northeastern Afar region had pushed back scientists' estimates for when human life began.
"The fossil bone was unearthed by Ethiopian PhD student Chalachew Seyoum, who is also a member of a team of scientists from Arizona University," said Prof. Kaye E. Reed, the lead researcher in a team of scientists from Arizona State University's Institute of Human Origins.
She added that the Jawbone predated previously known fossils of Homo sapiens by some 400,000 years.
The fossil, which has teeth attached to it, was discovered in 2013 in Ethiopia's Afar region.
"Researchers also found a fossil mammal assemblage contemporary with this jaw to be dominated by species that lived in more open habitats – grasslands – than those common at older Australopiticus-bearing sites such as Hadar," Reed said.
She added that the Ledi jaw had helped narrow the evolutionary gap between Australopiticus and early homo sapiens.
The researcher described the jawbone as an "excellent case of a transitional fossil in a critical time period in human evolution."
"We can see the 2.8-million-year aridity signal in the Ledi-Geraru faunal community," Reed said.
Nevertheless, she noted that it was still premature to presume that climate change was responsible for the origin of homo sapiens.
She said research would continue in the same area.
