We Have Really Been Around Longer

 

Our debut as humans just became a lot more historic.

A new study concludes that the earliest known humans appeared in southern Ethiopia around 195,000 years ago, about 35,000 years earlier than previously thought, based on what researchers say are the oldest anatomically modern human fossils ever found. Although leaving the full-fledged arrival of Homo sapiens far from resolved, the
"bombshell," as it’s being called by other scientists, suggests that roughly three-fourths of modern human evolution occurred within the African continent.

"This is really good news," said Sally McBrearty, a paleoanthropologist at the University of Connecticut in Storrs.

"It’s a great date for an incredibly important fossil – the date for
the oldest representative of our species," agreed Daniel Lieberman, a
biological anthropologist at Harvard.
 

Study co-author John
Fleagle, a professor of anatomical sciences at Stony Brook University,
said the research fits well with evidence that the last of our genes
became fully distinct from other primates around 200,000 years ago. It
supports other genetic studies showing that the bulk of human genetic
diversity occurring since then is found within Africa, before
inhabitants began emigrating to the Middle East, Europe, and Asia about
50,000 years ago.
 

If corroborated, the research may only widen
the poorly understood gap between the appearance of anatomically modern
humans and the profusion of cave painting and other "modern" behavior,
which records suggest also began about 50,000 years ago. "There’s a big
gap before humans got our act together," Fleagle said.

The study, appearing today in the journal Nature, relied on
re-examinations of several old archaeological sites. In 1967, an
international expedition led by anthropologist Richard Leakey, now a
visiting professor at Stony Brook, explored southern Ethiopia for signs
of early human evolution. At sites along the Omo River, a team of
Kenyan archaeologists found two partial skulls that were clearly
human-like in appearance, including one with the high forehead
characteristic of modern Homo sapiens. But with few means available to
conclusively date them, clear ages were never assigned to the
modern-looking fossil, Omo I, and the somewhat more primitive-looking
Omo II.

A new international expedition, including Fleagle and
his study co-authors, began revisiting Ethiopia in 1999. To date the
fossils, they used a method based on the decay of unstable forms of the
element argon.