Credit: M. S. LEWIS/CORBIS

Current Biol. doi:10.1016/j.cub.2008.12.049 (2009)

'Pygmy' is a blanket term for many Central African populations that have an average male height of 150 centimetres or less. Whether these groups share a common evolutionary divergence from other humans has been long-debated. But by comparing 28 genomic regions in 604 people — among them individuals from 9 Pygmy groups — Paul Verdu at the CNRS in Paris and his colleagues have confirmed the single-origin theory, and added to a part of recent human history.

The analysis suggests that Pygmies diverged from other human groups either 54,000 or 90,000 years ago (depending on whether the tallest Pygmy group, the Bongo, is included in statistical tests). They then remained as one interbreeding population until about 800 bc, when the agricultural expansion of their non-Pygmy neighbours seems to have driven a rapid genetic and cultural divergence among them.