Geneticists mapping the deep history of Southern Africa have discovered a 'ghost lineage' through the genomic analysis of 12,000-year-old remains from the Limpopo Basin. The study, appearing in Cell Genomics, identifies a unique genetic divergence in a population of hunter-gatherers who possessed specialized adaptations for resisting endemic neurotoxins carried by local tick species. This lineage, which appears to have been isolated during the Late Pleistocene, provides the first genetic evidence of localized evolutionary defense mechanisms against South African parasitic pathogens.
The research suggests that this group maintained a high degree of genetic distinctness for several millennia before merging with the ancestors of modern San and Khoe populations. The presence of these specific immune-response alleles highlights how the diverse ecological niches of the African continent drove rapid genomic selection in small, isolated communities. This discovery reshapes the map of human migration in Africa, suggesting that the interior river basins served as critical refugia where unique genetic traits were forged in response to local environmental threats.