GENETICS
The Deepest Human Divergence
between ~350,000 and ~260,000 years ago
Palaeolithic · Middle Stone Age · MIS 8
The oldest separation still readable in living human genomes dates back some 350,000 to 260,000 years, within Africa.
The deepest divergence among present-day human populations is the earliest separation that the genomes of the living allow to be reconstructed. Estimating it requires a genome unblurred by recent admixture, since every later migration weakens the older signal; the estimate was obtained from the remains of a boy who lived on the South African coast about two thousand years ago. The separation between the ancestors of present-day Khoe-San populations and those of all other humans is placed in this way between 350,000 and 260,000 years ago. The Khoe-San also display the greatest genetic diversity measured within any human group.
Why it matters
The significance of the result lies less in the date than in what it excludes, namely a recent and localised origin: human populations were already old and structured during the African Middle Stone Age, in the period of the Jebel Irhoud and Florisbad fossils. The form of that beginning remains disputed. One reading sees a single clean divergence; another a network of populations drifting apart and remixing over several hundred thousand years. The choice between the two models is among the open questions of population genetics.
Dating & uncertaintyDisputed
The estimate is genetic, and its interpretation is debated. Ancient genomes from South Africa place the first divergence among modern human populations between 350,000 and 260,000 years ago. A competing analysis reads the same signal as the trace not of a separation but of a weakly structured African stem, formed of two or more ancestral populations connected by gene flow over hundreds of thousands of years. In that second model, the first clean separation among present-day peoples falls closer to 135,000 to 120,000 years ago.
Our species’ history as one day
01:08:3422 h 51 min before midnight
if the 315,000 years of Homo sapiens were compressed into a single day