Long, long ago, a bold race of early modern humans left Africa and migrated across vast stretches of southern Asia to Australia - a mass migration of humankind that was followed thousands of years later by a second wave of African migrants who would settle all of Europe and the northern reaches of the Eurasian continent.
This new tale of humanity's movements out of Africa and around the world comes from an international team of geneticists who report they have traced the record of that first migration by sequencing the DNA from a single lock of hair of an unknown Australian Aborigine that had lain for nearly a century in a British museum.
The scientists maintain that instead of one human wave out of Africa, as has been traditionally believed, there must have been two. The first migration across southern Asia established the first Australians, the continent's Aboriginal population; the second migration, much later, saw modern humans, and, for a while, the Neanderthals, spread all across Europe and ultimately Asia.
That earlier migration took place more than 70,000 years ago, according to the geneticists, placing it at least 24,000 years before the second wave of humans that would later populate Europe, Asia and, eventually, America.
A report on this elaborate feat of genetic detective work was published online Thursday in the journal Science Express by a group of nearly 60 scientists led by geneticists Eske Willerslev and Morten Rasmussen of the University of Copenhagen.
The original work determining the sequence of DNA in the aboriginal hair was accomplished by Danish and Chinese scientists at their joint genomics center in Shenzhen, China, and was compared with DNA sequences from 79 individuals from Asia, Europe and Africa. The results were then sent to a group at UC Berkeley's Center for Theoretical Evolutionary Genomics.
No comments:
Post a Comment