DNA evidence has revealed that the oldest known common male ancestor is 340,000 years old, more than twice as old as previous estimates.
New Scientist reports that the sample comes from a recently deceased
man named Albert Perry. After the African-American South Carolina man
died, one of his relatives submitted a sample of his DNA to a company
called Family Tree DNA for analysis.
The findings were published in the The American Journal of Human Genetics and may require researchers to adjust the known timeline of humankind’s evolution.
And the historical mark came at something of a bargain—the company does historical DNA analysis on individuals for about $150.
All previously compared DNA samples pointed to a common Y chromosome
traced back to man who lived between 60,000 and 140,000 years ago. But
Perry’s DNA sample broke the trend, not matching up with this common
ancestor.
"It's a cool discovery," Jon Wilkins of the Ronin Institute
in Montclair, N.J., told New Scientist. "We geneticists have been
looking at Y chromosomes about as long as we've been looking at
anything. Changing where the root of the Y-chromosome tree is at this
point is extremely surprising."
After the initial tests on Perry’s DNA, geneticists at the University
of Arizona conducted further tests to confirm the anomaly. The Y
chromosome in Perry’s test matched up with those of 11 men who all lived
in one village in Cameroon.
University of Arizona researcher Michael Hammer says Perry’s DNA
suggests there may have been an earlier species of humans that went
extinct—but not before interbreeding with the more modern version of
man.
vendredi 8 mars 2013
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