Article at Phys Org (summary below)
May 28, 2015
New research suggests that European and Asian (Eurasian) peoples originated when early Africans moved north - through the region that is now Egypt - to expand into the rest of the world. The findings, published in the American Journal of Human Genetics, answer a long-standing question as to whether early humans emerged from Africa by a route via Egypt, or via Ethiopia.
The extensive public catalogue of the genetic diversity in Ethiopian and Egyptian populations developed for the project also now provides a valuable, freely available, reference panel for future medical and anthropological studies in these areas.
Two geographically plausible routes have been proposed for humans to emerge from Africa: through the current Egypt and Sinai (Northern Route), or through Ethiopia, the Bab el Mandeb strait and the Arabian Peninsula (Southern Route). Some lines of evidence have previously favoured one, some the other.
"The most exciting consequence of our results is that we draw back the veil that has been hiding an episode in the history of all Eurasians, improving the understanding of billions of people of their evolutionary history," says Dr Luca Pagani, first author from the Wellcome Trust Sanger Institute and University of Cambridge. "It is exciting that, in our genomic era, the DNA of living people allows us to explore and understand events as ancient as 60,000 years ago."
The team produced whole-genome sequences from 225 people from modern Egypt and Ethiopia. In previous studies, they and others have shown that these modern populations have been subject to gene flow from West Asian populations, so they excluded the Eurasian contribution to the genomes of the modern African people.
The remaining masked genomic regions from Egyptian samples were more similar to non-African samples and present in higher frequencies outside Africa than the masked Ethiopian genomic regions, pointing to Egypt as the more likely gateway in the exodus to the rest of the world.