‘As important [for the Bushmen] as the element of belonging, was the feeling of being known. Perhaps this more than anything else sets him apart from us and the rest of Africa,’ wrote Laurens van der Post in Testament to the Bushmen in 1984. Although he was working from observation and intuition, he may have been very close to the truth.
‘Khoisan hunter-gatherers in Southern Africa have always perceived themselves as the oldest people,’ says Professor Stephen Schuster, who led the project. ‘Our study proves that they truly belong to one of mankind’s most ancient lineages, and these high-quality genome sequences obtained from the tribesmen will help us better understand human population history, especially the understudied branch of mankind such as the Khoisan.’
The project compared five living individuals with 420,000 variants across 1,462 genomes from 48 ethnic groups in the global population. The research team found that individuals in the Khoisan population did not interbreed with any other ethnic groups for 150,000 years, and that the Khoisans were the majority living human group until 20,000 years ago.
The results mean it is now possible to use genetic sequencing to reveal the ancestral lineage for a group up to 200,000 years ago, providing the group contains individuals who have not mixed with other groups. This will allow researchers to identify intermarriages and geographical migrations that have occurred over many centuries.
Two individuals in the Ju/’hoansi tribe were found not to have an ancestry with an admixture of any other ethnic group. ‘It was very surprising that this group apparently did not intermarry with non-Khoisan neighbours for thousands of years,’ says Dr Hie Lim Kim, a research fellow on the project. Khoisan people and modern humanity share an ancestor 150,000 years ago. Current tradition sees Khoisans marrying outside their group.
‘A key finding from this study is that even today, after 150,000 years, single non-admixed individuals or descendants of those who did not interbreed with separate populations can be identified within the Ju/’hoansi population, which means there might be more such unique individuals in other parts of the world,’ adds Kim.
This story was published in the February 2015 edition of Geographical Magazine