Genome recovered from ancient African human

Oct 09, 2015, 5:13 PM EDT
A representative model of the skeleton 'Lucy' at the opening of the new permanent exhibition at the National Museum of Ethiopia featuring Lucy the 3.4 million year old fossil on December 3, 2014.
A representative model of the skeleton 'Lucy'. Getty Images

Scientists have reported that they have recovered the genome from a 4,500-year-old human skeleton in Ethiopia. This accomplishment marks the first time a complete assemblage of DNA has been retrieved from an ancient human in Africa. The New York Times reports:

The DNA of the Ethiopian fossil is strikingly different from that of living Africans. Writing in the journal Science, the researchers conclude that people from the Near East spread into Africa 3,000 years ago. In later generations, their DNA ended up scattered across the continent.
“It’s a major milestone for the field,” said Joseph Pickrell, an expert on ancient DNA at the New York Genome Center who was not involved in the study. For decades, scientists had doubted that ancient DNA could survive in the tropics. The study raises hopes that scientists can recover far older human genomes from Africa — perhaps dating back a million years or more.
“I would bet it’s not that far in the future,” said Lee Berger, a paleoanthropologist at the University of the Witwatersrand who recently announced the discovery of an ancient humanlike species called Homo naledi.
Scientists know that after the great migration from Africa, where all early humans originated -- treks that took place about 60,000 years ago -- some of the Eurasians who had developed agriculture made their way back into Africa. 
That's what makes the newly sequenced man, named Mota by scientists, so interesting. Mota lived in Africa before this second, backwards migration. Unsurprisingly, Mota lacked the Eurasian DNA that seems to have proliferated across the region about 1,500 years after his death.
By comparing his DNA -- extracted from a resilient inner ear bone, which has become the technique of choice for getting DNA in a tricky climate -- to that of modern Africans, scientists were able to estimate how large the Eurasian influx had been. 
"Roughly speaking, the wave of West Eurasian migration back into the Horn of Africa could have been as much as 30% of the population that already lived there - and that, to me, is mind-blowing. The question is: what got them moving all of a sudden?" Andrea Manica, senior author of the study from the University of Cambridge's Department of Zoology, said in a statement.