Evolution: Ancient human DNA and African population history

Analysis of ancient human DNA from western Central Africa offers insights into African population history, including the origin of speakers of the Bantu languages. The findings are reported in this week’s Nature.

Shum Laka in western Cameroon, Africa, is an important archaeological site for the study of Late Pleistocene and Holocene prehistory in western Central Africa. The area is located in the Grassfields region, which is thought to be the homeland of Bantu languages. David Reich, Mark Lipson and colleagues analysed ancient DNA from four children buried at this site (two from around 8,000 years ago and two from around 3,000 years ago, and found that their ancestry profiles are most similar to contemporary hunter-gatherers of western Central Africa. This finding implies that people living in western Cameroon, and speakers of Bantu languages across the continent, are not descended from these individuals or the population they represent.

The genomes also show signs of admixture, implying that the ancestors of these children interbred with individuals from different populations. In addition, three prominent radiations can be discerned, including one around 300,000 to 200,000 years ago, which gave rise to at least four major branches that contribute to present-day populations.