The Khoe and San peoples in southern Africa play an important role for our understanding of the evolutionary history of humans. These peoples are directly descended from the first branching of the genealogical tree of today’s humans. This is shown in a study led by Uppsala University researchers and being presented in the early online version of the journal Science today.
The study is based on an analysis of 2.3 million genetic variants from seven groups of the click-speaking Khoe and San peoples, a total of 220 individuals from southern Africa. The analysis is the largest genetic study ever of the Khoe and San peoples.
These peoples belong to a branch that diverged from other peoples at least 100 000 years ago. This was long before modern human´s diaspora from Africa and even long before the evolutionary diversification of Pygmies in Central Africa and before the emergence of the hunters and gatherers of East Africa.
The evolutionary history of humans in Africa is much more complex than we have believed so far. Our analyses show deep divergences among the various African peoples, with the deepest divergence involving the Khoe and San peoples, says Mattias Jakobsson, Uppsala University, who directed the study.
When modern humans began to spread outside Africa 60-70 000 years ago, there were already clear stratification among African populations. Our data suggest that there was no single geographical origin but that several populations contributed genes to the ancestral population that lead to today’s humans.