New study decodes Middle East's genetic history

Dubai - Scientists from the UK, UAE, and Saudi Arabia reconstruct genetic history of Middle Easterners from the last 125,000 years.

A team of scientists from the UK, UAE, and Saudi Arabia has uncovered the genetic code of the Middle Eastern populations.

The team discovered that the ancestry of most present-day people from the Arabian Peninsula is drawn from ancient hunter-gatherers as well as from regional Bronze Age populations. This includes ancestry from an enigmatic population that exited Africa around 60,000 years ago, but is genetically different from all other main Eurasians.

In the first study of its kind, researchers have reconstructed the genetic history of Middle Easterners from the last 125,000 years.

The study, conducted by the University of Birmingham and the Wellcome Sanger Institute, analysed DNA data from hundreds of people across the Middle East to reconstruct their genetic history.

It found that Bronze Age people from the Levant or Mesopotamia may have spread Semitic languages to Arabia and East Africa.

Populations all over the Middle East grew similarly until 15,000 to 20,000 years ago. After that, the Levantine populations continued to grow, while Arabian populations remained static – “a trend which emerged as agriculture developed in the Fertile Crescent, leading to settled societies supporting larger populations”.

Researchers found millions of novel genetic variants common in the region but rare elsewhere.

The study represents the first comprehensive open-access human whole-genome dataset from the Middle East.

Publishing their findings in Cell, the team also found that variants associated with type-2 diabetes have increased in frequency recently due to selection. This challenges the assumption that high rates in the Middle East are caused solely by a recent shift to a sedentary lifestyle.

Lead author, Dr Mohamed Almarri from the Wellcome Sanger Institute and Dubai Police GHQ, said: “Our analyses illustrate the effect of lifestyle and climate on the demographic history of the populations in the region, and the contrasts between the Levant and Arabia.”

Corresponding author, Dr Marc Haber from the University of Birmingham, said the team has reconstructed “Middle Easterners’ genetic history in unprecedented detail to resolve long standing questions in population genetics”.

“We uncover why Arabians have less Neanderthal ancestry than other non-Africans; the genetic impact of agriculture in the Middle East; the spread of Semitic languages and their link to ancestry; as well as the impact of climate events on population sizes.”

• UAE