for National Geographic News
Analysis of sediments at two grave sites at Lake Mungo confirms that Australia is the site of the world's oldest known burial with red ochre and the oldest cremation, and provides additional evidence that early humans first reached Australia about 50,000 years ago.
Mungo Man and Mungo Lady, as they are known to the local Aborigines, both died and were buried around 40,000 years ago, reports a team of scientists.
"Mungo Man and Mungo Lady are both the same age, inseparable in time," said Jim Bowler, a geomorphologist and professor at the University of Melbourne and lead author of the study. "We now have a picture of a real community on the lake shores at 40,000 years ago (plus or minus 2,000 years)."
Mungo Lady's cremated remains were discovered at Lake Mungo in 1969. Five years later, Bowler uncovered the skeleton of Mungo Man about 1,500 feet (450 meters) from Mungo Lady's grave.
The ages of the remains have been the focus of scientific inquiryand disputefor more than 25 years. Mungo Man's remains were estimated variously at 30,000 years old, and somewhere between 42,000 to 45,000 years old. Scientists estimated Mungo Lady to be 20,000 to 26,000 years old.
In 1999, scientists led by Alan Thorne, an anthropologist who had discovered Mungo Lady, extracted mitochondrial DNA from the bones of Mungo Man. The team determined that he was 62,000 years old. The results were extremely controversial.
Debate has been raging ever since. The multi-disciplinary team of scientists reporting in the February 20 issue of the journal Nature say not only did the burials occur close to the same time, they also question whether there were humans at the site 62,000 years ago.
"Our study shows that humans were present at Lake Mungo as early as 50,000 to 46,000 years ago," the authors write. "We find no evidence to support claims for human occupation or burials near 60,000 years ago."
The dates matter because they have implications for determining when humans first left Africa, and where they went.
Archaeological, fossil, and genetic evidence support the "Out of Africa" model of modern human origins, which holds that all modern humans evolved in Africa, and then went on to populate the rest of the world, driving earlier hominid species to extinction.
Fossil evidence shows that there were modern humans in Africa by 130,000 years ago. Around 50,000 years ago, whether because of a sudden genetic modification, or simply the accumulation of skills over a period of 70,000 years, humans began to migrate out of Africa. Whether there were earlier, smaller, waves of migrations remains a matter of debate.
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