April 14, 2009

African pygmy genetics are traced

A French-led study has plotted African pygmies' ancestry, determining the pygmies' ancestors and neighboring farmers separated about 60,000 years ago.

The researchers at the Pasteur Institute said all African Pygmies living in Central Africa descend from a unique population who lived around 20,000 years ago. Pygmies are characterized by a forest-dwelling hunter-gathering lifestyle, distinctive cultural practices and physical traits, especially short stature.

Two groups of Pygmy populations live in the African rainforests: the Western Pygmies and the Eastern Pygmies. The common origins of the two groups of pygmies, separated by thousands of miles, have been long debated, and their relationships with neighboring farmers remained obscure.

The researchers led by Lluis Quintana-Murci studied the genetic profile of 12 Pygmy populations and neighboring farmers dispersed over the African continent. Using sequence data from non-coding regions of their genomes and simulation-based procedures, they determined the ancestors of Pygmy hunter-gatherers and farming populations started to diverge about 60,000 years ago, coinciding with a period of human migration both within and outside Africa.

The study appears in the journal PLoS Genetics.