Humans split from other primates much earlier than thought

A common ancestor of apes and humans evolved in Africa -- not Eurasia -- two million years earlier than previously thought, new fossil analysis of the species Chororapithecus abyssinicus has revealed.

"Our new research supports early divergence: 10 million years ago for the human-gorilla split and eight million years ago for our split from chimpanzees," said one of the researchers Giday WoldeGabriel from Los Alamos National Laboratory in New Mexico, US.

"That's at least two million years earlier than previous estimates, which were based on genetic science that lacked fossil evidence," WoldeGabriel noted.

"Our analysis of C. abyssinicus fossils reveals the ape to be only eight million years old, younger than previously thought. This is the time period when human and African ape lines were thought to have split, but no fossils from this period had been found until now," WoldeGabriel explained.

The discovery of the extinct gorilla-like species C. abyssinicus from Ethiopia's Chorora area was reported in the journal Nature in 2007.

In the new study which was also reported in the journal Nature, the researchers used a variety of methods to determine the age of teeth they found at Chorora.

Through fieldwork, volcanic ash chemistry and geochronology, WoldeGabriel helped nail down the age of the fossils to approximately eight million years old.

Based on this new fossil evidence and analysis, the team suggests that the human branch of the tree (shared with chimpanzees) split away from gorillas about 10 million years ago -- at least two million years earlier than previously claimed.