- United States
Tracing African ancestry reveals human mystery
high levels of mixed ancestry in most populations
After a 10 year study of African genes, scientists have discovered that the first humans probably evolved near the South Africa-Namibia border before migrating north out of the continent, via the Red Sea. The study is reported to be the most comprehensive study ever carried out on African genes.
Published in the US journal, Science, the results of the study aims to teach Africans on population history and aid research into why diseases hit particular groups. According to the review, the scientists examined genetic material from 121 African populations, as well as four African-American populations and 60 non-African populations. The findings made from observing African-American populations showed that almost three-quarters could trace their ancestry to West Africa.
According to Sarah Tishkoff, a geneticist from the University of Pennsylvania, “The results provided novel insights about levels and patterns of genetic diversity in Africa, a region that has been under-represented in human genetic studies.”
The researchers are reported on BBC to have to have found high levels of mixed ancestry in most populations, as well as evidence showing common ancestry in geographically diverse groups. They had identified 14 ancestral population clusters that correlated with ethnicity and shared cultural and/or linguistic properties.
“This study will benefit Africans, both by learning more about their population history and by setting the stage for future genetic studies, including studies of genetic and environmental risk factors for disease and drug response,” Dr. Tishkoff added.
In an earlier report published in the American Journal of Human Genetics, a genetic study suggested that ancient humans started down the path of evolving into two separate species before merging back into a single population. The genetic split in Africa resulted in distinct populations that lived in isolation for as much as 100,000 years.
The researchers of this earlier study revealed that a major split occurred some 150,000 years ago: One side of the divide now found predominantly in East and West Africa, and all maternal lineages found outside Africa.
Although present-day people carry a signature of the ancient split in their DNA, today’s Africans are part of a single population. On the other side of the divide are lineages predominantly found in the Khoi and San (Khoisan) hunter-gatherer people of southern Africa. Many African populations today harbor a mixture of both.