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Arabia identified as key stop in early human migrations

Jan. 28, 2012
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 Jan. 26 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 Luísa Pe­rei­ra of the Un­ivers­ity of Porto in Por­tu­gal, 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.”

The work, led by Pe­rei­ra and Mar­tin Rich­ards at the Un­ivers­ity of Leeds in the U.K., ex­plored the ques­tion by an­a­lyz­ing 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.


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Arabia was the first “staging post” for humans when they first migrated out of their ancestral home of Africa, said 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 Jan. 26 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 Luísa Pereira of the University of Porto in Portugal, 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.” The work, led by Pereira and Martin Richards at the University of Leeds in the U.K., explored the question by analyzing 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 stored in a separate cellular compartment from the rest of the DNA and that 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.