(Chalachew Seyoum holding jawbone. Photo: Brian Villmoare)
On January 29, 2013, Chalachew Seyoum made groundbreaking discovery that will help to shed light on the earliest living humans. The Arizona State graduate student found a jawbone at the Ledi-Geraru research area in the Afar region of Ethiopia. The jawbone has since been confirmed as being about 400,000 years older than previously discovered specimens from the genus Homo. The specimen also dates back to about 200,000 years after the latest Australopithecus afarensis specimen, famously known as “Lucy,” a completely specimen which was also discovered in the region. It is believed that the individual from which the jawbone came, might have lived approximately 2.8 million years ago.
According to the Guardian,
“By finding this jaw bone we’ve figured out where that trajectory started,” said Villamoare. “This is the first Homo. It marks in all likelihood a major adaptive transition.”
What drove Australopithethus to extinction and led to the rise of Homo is a mystery, but researchers suspect a dramatic change in the environment transformed the landscape of eastern Africa. “It could be that there was some sort of ecological shift and humans had to evolve or go extinct,” said Villmoare.
Other fossils recovered nearby the new human remains suggest that the region was much wetter than Hadar where Lucy was found. Remnants of antelopes, prehistoric elephants, primitive hippos, crocodiles and fish were all recovered from the Ledi-Geraru site, researchers said. Details of the discoveries are reported in two papers published in Science.
The discoveries made by this U.S.-led team are laid out in detail in this paper published in Science Magazine.