Recent genetic research has uncovered that ancient humans in southern Africa lived in near-total isolation for almost 100,000 years. This long period of separation led to the development of unique genetic traits that are strikingly different from those found in modern populations. The study, which sequenced genomes from 28 ancient individuals, demonstrates that early Homo sapiens exhibited extraordinary genetic diversity. These findings provide valuable insights into human evolution, showing how isolated populations adapted to their environments over millennia. Additionally, the research sheds light on early migration patterns, population sizes, and the combination of genetic variants that contributed to the emergence of modern humans, deepening our understanding of humanity’s complex evolutionary history.
Ancient Southern African humans lived in genetic isolation for nearly 100,000 years
The study published in Nature sequenced the genomes of 28 ancient individuals from southern Africa, whose remains dated between 225 and 10,275 years ago. The samples were collected south of the Limpopo River, which flows through South Africa and Mozambique. Analysis revealed that these populations “fall outside the range of genetic variation” observed in contemporary humans. This indicates that they formed an extreme end of human genetic diversity, shaped by prolonged isolation and limited interaction with neighbouring populations.Geographical barriers and challenging environmental conditions likely contributed to this separation. Areas north of the region, such as around the Zambezi River, may have been unsuitable for early human habitation, which limited gene flow from other populations.
Ancient isolated South Africans’ genetic findings and unique traits
The ancient southern Africans carried half of all known human genetic variation, with the rest distributed globally. Among these genomes, researchers identified unique human-specific variants linked to kidney function, which may have helped in water retention, and neuronal development, which may have contributed to cognitive capabilities. These traits suggest that ancient southern Africans were highly adapted to their environment and possibly had mental advantages compared with other archaic humans, such as Neanderthals and Denisovans.Statistical modelling indicates that the southern African population remained large until at least 200,000 years ago. During favourable climatic periods, some individuals may have migrated north, spreading their genes to other regions. Around 50,000 years ago, the population began to decline. Approximately 1,300 years ago, incoming farmers from northern regions began interacting and reproducing with local foragers, introducing new genetic material into the southern African gene pool.
Southern African genomes highlight complex human evolution
The study supports a combinatorial model of human evolution, in which multiple isolated populations with unique genetic combinations eventually contributed to the emergence of genetically modern Homo sapiens. Ancient southern Africans, with their distinct genetic variants, provide crucial evidence that human evolution was not a linear process but a complex interplay of multiple populations, adaptations, and migrations.Also Read | ESA discovers butterfly-shaped crater on Mars revealing impact, volcanic activity, and possible water
