Sub-Saharan Africa’s 4000-year legacy of past migrations

Researchers from the University of Oxford have revealed that the genetic ancestries of many of sub-Saharan Africa's populations are the result of historical DNA mixing events, known as admixture, within the last 4000 years. Their study, to be published in the journal eLife, uncovers signatures of these admixture events through a large analysis of DNA from populations across the continent. The discovery provides a foundation for the recent genetic history of the continent, which could aid future studies of non-communicable and infectious diseases, such as malaria. Looking at and comparing the differences in the genomes of people alive today can help us better understand and reconstruct the historical interactions that brought their ancestors together. Dr George Busby, Wellcome Trust Centre for Human Genetics - While admixture has been demonstrated in other regions of the world, the new analysis has allowed the team to characterise sub-Saharan Africa's mixing events in an unprecedented level of detail. 'As Africa has few written records of its history, it is somewhat unknown what important movements of people generated the populations in the continent today,' says lead author George Busby, Statistical Geneticist at the Wellcome Trust Centre for Human Genetics. 'Looking at and comparing the differences in the genomes of people alive today can help us better understand and reconstruct the historical interactions that brought their ancestors together.' The team used DNA analysis to characterise the structure of genetic diversity and gene flow - the transfer of genes between different populations - in a collection of 48 sub-Saharan African groups.