« No Neanderthal in Our Blood, But Did Our Ancestors Try?
Main
Gas Too High? »
February 16, 2005
Just How Old Are We?
Nature reports that Ian McDougall, John Fleagle and others have rethought the date of the skull known as, Omo II. John Leakey found this skull in Ethiopia and dated to about 130,000 BP (before the present). McDougall and team now think the faceless skull, that is virtually identical to modern man's, is from 196,000 BP or slightly more recent. The new dating relies on radioactive argon decay in the rock that formed the substrate on which Leaky found Omo II. The team took new samples. Because of the rapid build up of volcanic deposits in the area, the date of Omo II (and Omo I for that matter) is only slightly more recent than the rock on which it rested
"In 1967, dating techniques weren't what they are now," says John Fleagle of Stony Brook University, New York, who took part in the latest analysis, published in Nature1. And besides, Leakey and his colleagues were more concerned with hunting for something millions of years older. "The fact of the matter is, they wanted early hominids; modern humans were like chump change," Fleagle says.As a result, nobody attempted to date the fossils' burial site more accurately, despite its significance in helping to settle the debate over humanity's African roots. "When modern human origins became a big issue in the early 1980s, Ethiopia was closed," Fleagle says."
What this means is that our species is likely older than previously thought and it adds increasing support to the out of Africa theory.
The age of the Omo fossils provides yet more support for the 'out of Africa' theory, which contends that humankind spent most of its life in Africa, before sweeping across the world during the past 40,000 years. "The finds confirm that east Africa was a key area in this story," says Chris Stringer, who studies human origins at the Natural History Museum in London.
This new dating makes Omo II older than the previously candidate for the oldest human specimen. That was the hominid fossils called H. sapiens idaltu, meaning 'elder', from Herto Ethiopia: thought to be 160,000 BP. See the article on H. sapiens idaltu written by Jim Foley. Foley says of them,
The discoverers have assigned them to a new subspecies, Homo sapiens idaltu, and say that they are anatomically and chronologically intermediate between older archaic humans and more recent fully modern humans. Their age and anatomy is cited as strong evidence for the emergence of modern humans from Africa, and against the multiregional theory which argues that modern humans evolved in many places around the world.
Omo II appears more "human" than Homo sapiens idaltu and the new, earlier dating, certainly would suggest that our family tree is older and bushier than previously thought. What does this have to do with the origin of human speech? Nothing.
Posted by Duane Smith at February 16, 2005 12:19 PM | Read more on Paleoanthropology |
Trackback Pings
TrackBack URL for this entry:
http://www.telecomtally.com/mt/mt-tb.cgi/1052