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Arabia identified as key stop in early human migrations

Posted by Bridget in Life, Palaeontology

Courtesy of Cell Press and World Science staff

Arabia was the first ‘staging post’ for humans when they first migrated out of their ancestral home of Africa, says a scientist involved in a newly published study on the subject.

The timing and pattern of the migration of early modern humans has been a source of much debate and research. The new investigation used genetic analysis to look for clues about the migration of the first modern humans believed to have moved out of Africa, more than 60 000 years ago.

The research, published 0n 26 January in the American Journal of Human Genetics, suggests modern humans settled in Arabia on their way from the Horn of Africa to the rest of the world.

‘A major unanswered question regarding the dispersal of modern humans around the world concerns the geographical site of the first steps out of Africa,’ said senior study author University of Porto in Portugal’s Luísa Pereira, one of the co-authors. ‘One popular model predicts that the early stages of the dispersal took place across the Red Sea to southern Arabia, but direct genetic evidence has been thin on the ground.’

A staging post

The work, led by Pereira and Martin Richards at the University of Leeds in the UK, explored the question by analysing three of the earliest non-African maternal lineages. These early branches are associated with the time period when modern humans first successfully moved out of Africa. The team compared DNA from Arabia and the Near East with a database of hundreds more samples from Europe.

‘Taken together, our results suggest that Arabia was indeed the first staging-post in the spread of modern humans around the world,’ Richards said.

The study used mitochondrial DNA, a part of the human genome that’s stored in a separate cellular compartment from the rest of the DNA and is considered useful for comparing relatedness between populations. Mitochondrial DNA is inherited only from the mother, so it provides information on the female line of descent.

The Arabian peninsula from space. (Image: Wikimedia Commons)