Above that, the San ancestors are not the oldest branch of all humanity - instead, the data suggest the existence of a more basal (primordial) lineage that significantly influenced the genetics of the West African population. For example, the Yorubas (Nigeria) and Mende (Sierra Leone) differ in the proportion of this ancient lineage. Erectus? Heidelbergensis? We don't know, because we still don't have extracted DNA. The study "Reconstructing Prehistoric African Population Structure" (Skoglund et al., 2017, Cell) analyzes the genomes of 16 ancient Africans from 1400-8100 years ago to reconstruct the population structure of the continent before the expansion of agriculture. Here is a summary of the main results: 1. the range of ancient San hunter-gatherers. The genomes of hunter-gatherers from Malawi (8100-2500 years ago) and Tanzania (1400 years ago) contain a large genetic contribution (up to 65%) from populations closely related to today's southern African San. This suggests that San ancestors were once widely distributed in East Africa as well. 2 Population replacement by farmers and pastoralists. The expansion of the Bantu population from West Africa (last 2,000 years) has completely replaced the former hunter-gatherers in regions such as Malawi. A pastoralist from Tanzania (about 3100 years ago) whose ancestors were 38% from the Neolithic Levant (today's Middle East) has been identified. His descendants contributed to the establishment of pastoralist populations throughout East and Southern Africa. 3 The Oldest Branches of Human Ancestry The San ancestors are not the oldest branch of all humanity - instead, the data suggest the existence of a more basal (primordial) lineage that significantly influenced the genetics of West African populations. For example, the Yorubas (Nigeria) and the Mende (Sierra Leone) differ in the proportion of this ancient lineage. 4 Detecting signals of natural selection. Signs of natural selection dating back 2,000 years have been observed in the genome of modern San, including: Taste receptor cluster (chromosome 12) - potentially related to plant toxin detection. Radiation response genes - possibly reflecting adaptation to insolation in the Kalahari Desert. Conclusions: Africa's population structure before the expansion of farmers was much more diverse than it is today. Some ancient ancestral lineages (such as those associated with the San) have been almost completely replaced. Only analysis of ancient genomes allows reconstruction of this complex past - studies of modern populations are insufficient.