On Thursday, scientists said the ancient human, dubbed as “Mota”, is the first ancient human from Africa whose DNA has been sequenced to reveal the history of this part of the world.
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The first-ever DNA sequencing of the skull of an ancient African – the 4,500-year old “Mota man” discovered in an Ethiopian cave – has revealed that a huge migration from Western Eurasia into the Horn of Africa 3,000 years ago was twice as significant in terms of numbers and genetic influence as had been thought.
The DNA confirms the migrants were from what is now the Middle East and were direct descendants of the Neolithic farmers who brought agriculture into Europe 7,000 years ago but then returned to Africa 4,000 years later.
By comparing the genome of Mota and DNA from modern Africans, researchers found that today’s East Africans have approximately 45 percent Eurasian ancestry because of the ancient migration.
Beyond the region, African populations across the continent can trace at least five percent of their genome to the Eurasian migration.
“While previous studies have documented substantial West Eurasian ancestry in a few sub-Saharan African populations, including Nigerians and KhoeSan from southern Africa, if the findings of this paper are right, they are important because they extend these claims to populations that were previously thought to have little or no West Eurasian ancestry, for example Mbuti hunter gatherers from central/east Africa”. “Until now, what we had to do was to take the genome, the information that we have from modern Africans, and use that as our effectively representative” sample.
It’s not clear why they moved, though one theory that’s been suggested is that farmers looking for fertile land traveled up the Nile.
The cause of the mass movement remains a mystery.
These Eurasians were closely related to the people who introduced agriculture to Europe 8,000 years ago, Gallego Llorente said. The study was published Wednesday in the journal Science. Indeed, it was so large that it could have increased the population of the Horn of Africa by close to a third – which in turn led to a bigger genetic impact than expected, the report found. “One genome from one individual can provide a picture of an entire population”, said Manica. “The famers found their way to Sardinia and created a bit of a time capsule”. “It’s quite remarkable that genetically-speaking this is the same population that left the Near East several millennia previously”, said Eppie Jones, a geneticist at Trinity College Dublin who led the laboratory work to sequence the genome.
Researchers used the petrous bone – a thick part of the temporal bone at the base of the skull, just behind the ear – to find the ancient DNA which they then sequenced.
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Commenting on the research, Dr Carles Lalueza-Fox, from the Institute of Evolutionary Biology in Barcelona, Spain, said: “What is nice is that it places in time the origin of the Eurasian backflow into Africa already detected a few years ago from modern genome data, and it turns out to be the farming”.
