February 9, 2016

Weill Cornell Team Finds New Human Migration Pattern

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A team of genome researchers from Weill Cornell Medicine in New York and Qatar  have  discovered that indigenous Arabs can directly trace their ancestors to migrants from Africa.

A conclusion which the team published in January’s edition of Genome Research and contradicts long-standing beliefs about human migration and evolution patterns, according to the University press.

“Our study shows that, if you look at the entire genome, not only was a residual population on the Arabian peninsula established after the out of Africa migration but indigenous Arabs currently residing on the Arabian peninsula can trace part of their ancestry back to this ancient population,”said Jason Mezey, a professor of biological statistics and computational biology at Cornell and genetic medicine at Weill Cornell Medicine.

According to Mezey, scientists have proposed multiple theories about the trajectory of human migration.  Before this study, scientists commonly believed that the original strain of the population that migrated out of Africa had ultimately died out because the Arabian Peninsula today is a mix of Arabs, Europeans and other neighboring regions.

In this study, researchers sequenced the genomes of 104 Arabian Peninsula natives and compared them with 1,092 genomes from worldwide populations, according to the University . They were able to group participants based on genome similarities to create an evolutionary tree.

“The genomes of the Arab individuals were found to statistically cluster within the broad group of non-African peoples but while they clustered within this broad group, the genomes of the Arab individuals also formed their own distinct cluster that was outside of to all other non-Africans,” Mezey said. “This pattern in the clustering would only be expected if Arabs could trace a portion of their ancestry to populations established on the Arabian Peninsula after the out-of-Africa migrations.”

The publication notes that not only will such findings will have an immense impact on the indigenous Arab population as it provides them with information about their genetics, but it could also have an immense impact on modern medicine.

“Beyond the importance for disentangling human migration history, an early split of Eurasian lineages in the Arabian Peninsula has implications for the study of disease genetics for indigenous people in the region,” the publication states. “This suggests that for any genome-wide association study (GWAS) or rare variant association study (RVAS) of diabetes or other complex diseases in Qatar, inference of deep ancestry in the Arabian Peninsula, using rare variation sampled by genome or exome sequencing, is critical for identifying new disease risk genes.”

Mezey explained that in the future he plans to expand the genome sequence with larger sample sizes.

“One of the exciting things of genomics is that more and more people are being sequenced,” Mezey said. “Soon we will be able to look at the sequences of anywhere from 100,000 people to an entire population. The more genomes you have, the more accurate inferences you can make about many topics including this one.”

The researchers note that their work would not have been possible without recent advancements in genetic technology, according to the University.