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Fossil Rolls Back Human History 400,000 Years

Fossil Rolls Back Human History 400,000 Years

A fossil jawbone dating back almost three million years has provided evidence that the first humans emerged 400,000 years earlier than previously thought.

The artefact unearthed in Ethiopia and dated to 2.8 million years old narrows the evolutionary gap between the first humans and their ape-like ancestors, according to scientists.

Until now the earliest known fossil of the Homo genus was 2.3 million years old, found less than 20 miles from the latest discovery, known as LD 350-1.

Specimens more than 2.5 million years old have been hard to find and are poorly preserved.

Dr Brian Villmoare, from the University of Nevada, who co-led the fossil hunters, said: "In spite of a lot of searching, fossils on the Homo lineage older than two million years ago are very rare.

"To have a glimpse of the very earliest phase of our lineage's evolution is particularly exciting."

His colleague Dr William Kimbel, director of the Institute of Human Origins at Arizona State University, said: "The Ledi jaw helps narrow the evolutionary gap between Australopithecus and early Homo.

"It's an excellent case of a transitional fossil in a critical time period in human evolution."

One theory is that global climate change and the resulting arid conditions led to the emergence of the very first humans that gave rise to the current species of Homo sapiens.

While other fossils found with the jawbone included those of animals associated with more arid habitats, the scientists said more evidence was needed.

The findings appear in the online edition of the journal Science.