The Dawn of Human Matrilineal Diversity

Abstract

The quest to explain demographic history during the early part of human evolution has been limited because of the scarce paleoanthropological record from the Middle Stone Age. To shed light on the structure of the mitochondrial DNA (mtDNA) phylogeny at the dawn of Homo sapiens, we constructed a matrilineal tree composed of 624 complete mtDNA genomes from sub-Saharan Hg L lineages. We paid particular attention to the Khoi and San (Khoisan) people of South Africa because they are considered to be a unique relic of hunter-gatherer lifestyle and to carry paternal and maternal lineages belonging to the deepest clades known among modern humans. Both the tree phylogeny and coalescence calculations suggest that Khoisan matrilineal ancestry diverged from the rest of the human mtDNA pool 90,000-150,000 years before present (ybp) and that at least five additional, currently extant maternal lineages existed during this period in parallel. Furthermore, we estimate that a minimum of 40 other evolutionarily successful lineages flourished in sub-Saharan Africa during the period of modern human dispersal out of Africa approximately 60,000-70,000 ybp. Only much later, at the beginning of the Late Stone Age, about 40,000 ybp, did introgression of additional lineages occur into the Khoisan mtDNA pool. This process was further accelerated during the recent Bantu expansions. Our results suggest that the early settlement of humans in Africa was already matrilineally structured and involved small, separately evolving isolated populations.

A multidisciplinary reconstruction of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilisation

“…America, with the hunter -gatherer Hadzabe of Tanzania separated from the Juj'hoansi (previously called !Kung) from Botswana by a genetic distance greater than between any other pair of populations (89) , which indicates the chronology of continent inhabitation and points to South or East Africa as the cradle of humankind (89,90) . Human evolution was characterised by several large-scale decimations, and it has been estimated that the current world population derives from only 1000 surviving individuals at a certain time point (91) . Such bottlenecks (92) , characterised by strong population decrease, or where groups of hominids were separated due to global climate changes, volcanic winters or geographic boundaries as mountain ridges or seas, caused gene flow and genetic drift.…”

Mitochondrial DNA control region data from indigenous Angolan Khoe-San lineages

“…Within our dataset, we found 90.7% L0 haplotypes, hence it is remarkable that 97.4% of all L0 haplotypes (or 88.4% of the observed Khoe-San dataset) belonged to the Khoe-San specific L0d/L0k cluster which is reported to account for ~ 60% in observed Khoe-San populations [19]. Among these, the most frequent haplogroups within the Angolan Khoe-San samples were L0d1c1 (33.3%) as well as L0k1 (27.1%).…”

The fallacy of racial pharmacogenomics

“…Africa is still poorly studied from the genetic standpoint. However, considering the fact that humankind has spent two thirds of it evolutionary history in Africa (12) and also the tremendous variety of human geographical environments (forests, savannahs, deserts, mountains) on that vast continent, it is expected that allele frequencies at several pharmacogenomic loci should vary considerably in different regions.…”

“…The panel even lacks samples from northeast Africa, from where humans migrated 60,000 years ago to populate the rest of the world (12).…”