Copyright © 2008 The American Society of Human Genetics. All rights reserved.
The American Journal of Human Genetics, Volume 82, Issue 5, 1130-1140, 24 April 2008
doi:10.1016/j.ajhg.2008.04.002
Article
Doron M. Behar1, 13,
,
, Richard Villems2, 13, Himla Soodyall3, Jason Blue-Smith4, Luisa Pereira5, 6, Ene Metspalu2, Rosaria Scozzari7, Heeran Makkan3, Shay Tzur1, David Comas8, Jaume Bertranpetit8, Lluis Quintana-Murci9, Chris Tyler-Smith10, R. Spencer Wells4, Saharon Rosset11, 12, The Genographic Consortium14
1 Molecular Medicine Laboratory, Rambam Health Care Campus, Haifa 31096, Israel
2 Department of Evolutionary Biology, University of Tartu and Estonian Biocentre, Tartu 51010, Estonia
3 School of Pathology, Division of Human Genetics, National Health Laboratory Service and University of the Witwatersrand, Johannesburg 2000, South Africa
4 Mission Programs, National Geographic Society, Washington, D.C. 20036, USA
5 Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto 4200-465, Portugal
6 Medical Faculty, University of Porto, Porto 4200-319, Portugal
7 Dipartimento di Genetica e Biologia Molecolare, Sapienza Università di Roma, Rome 00185, Italy
8 Evolutionary Biology Unit, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona 08003, Catalonia, Spain
9 Unit of Human Evolutionary Genetics, CNRS URA3012, Institut Pasteur, Paris 75724, France
10 The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
11 Data Analytics Research Group, IBM T.J. Watson Research Center, Yorktown Heights, NY 10598, USA
12 Department of Statistics and Operations Research, School of Mathematical Sciences, Tel Aviv University, Tel Aviv 69978, Israel
Corresponding authorAbstract
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.
| The Making of the African mtDNA Landscape The American Journal of Human Genetics, Volume 71, Issue 5, 1 November 2002, Pages 1082-1111 Antonio Salas, Martin Richards, Tomás De la Fe, María-Victoria Lareu, Beatriz Sobrino, Paula Sánchez-Diz, Vincent Macaulay and Ángel Carracedo Abstract Africa presents the most complex genetic picture of any continent, with a time depth for mitochondrial DNA (mtDNA) lineages >100,000 years. The most recent widespread demographic shift within the continent was most probably the Bantu dispersals, which archaeological and linguistic evidence suggest originated in West Africa 3,000–4,000 years ago, spreading both east and south. Here, we have carried out a thorough phylogeographic analysis of mtDNA variation in a total of 2,847 samples from throughout the continent, including 307 new sequences from southeast African Bantu speakers. The results suggest that the southeast Bantu speakers have a composite origin on the maternal line of descent, with ∼44% of lineages deriving from West Africa, ∼21% from either West or Central Africa, ∼30% from East Africa, and ∼5% from southern African Khoisan-speaking groups. The ages of the major founder types of both West and East African origin are consistent with the likely timing of Bantu dispersals, with those from the west somewhat predating those from the east. Despite this composite picture, the southeastern African Bantu groups are indistinguishable from each other with respect to their mtDNA, suggesting that they either had a common origin at the point of entry into southeastern Africa or have undergone very extensive gene flow since. Abstract | | |
| mtDNA Variation in the South African Kung and Khwe—and Their Genetic Relationships to Other African Populations The American Journal of Human Genetics, Volume 66, Issue 4, 1 April 2000, Pages 1362-1383 Yu-Sheng Chen, Antonel Olckers, Theodore G. Schurr, Andreas M. Kogelnik, Kirsi Huoponen and Douglas C. Wallace Abstract The mtDNA variation of 74 Khoisan-speaking individuals (Kung and Khwe) from Schmidtsdrift, in the Northern Cape Province of South Africa, was examined by high-resolution RFLP analysis and control region (CR) sequencing. The resulting data were combined with published RFLP haplotype and CR sequence data from sub-Saharan African populations and then were subjected to phylogenetic analysis to deduce the evolutionary relationships among them. More than 77% of the Kung and Khwe mtDNA samples were found to belong to the major mtDNA lineage, macrohaplogroup L* (defined by a HpaI site at nucleotide position 3592), which is prevalent in sub-Saharan African populations. Additional sets of RFLPs subdivided macrohaplogroup L* into two extended haplogroups—L1 and L2—both of which appeared in the Kung and Khwe. Besides revealing the significant substructure of macrohaplogroup L* in African populations, these data showed that the Biaka Pygmies have one of the most ancient RFLP sublineages observed in African mtDNA and, thus, that they could represent one of the oldest human populations. In addition, the Kung exhibited a set of related haplotypes that were positioned closest to the root of the human mtDNA phylogeny, suggesting that they, too, represent one of the most ancient African populations. Comparison of Kung and Khwe CR sequences with those from other African populations confirmed the genetic association of the Kung with other Khoisan-speaking peoples, whereas the Khwe were more closely linked to non–Khoisan-speaking (Bantu) populations. Finally, the overall sequence divergence of 214 African RFLP haplotypes defined in both this and an earlier study was 0.364%, giving an estimated age, for all African mtDNAs, of 125,500–165,500 years before the present, a date that is concordant with all previous estimates derived from mtDNA and other genetic data, for the time of origin of modern humans in Africa. Abstract | | |
| Extensive Female-Mediated Gene Flow from Sub-Saharan Africa into Near Eastern Arab Populations The American Journal of Human Genetics, Volume 72, Issue 4, 1 April 2003, Pages 1058-1064 Martin Richards, Chiara Rengo, Fulvio Cruciani, Fiona Gratrix, James F. Wilson, Rosaria Scozzari, Vincent Macaulay and Antonio Torroni Abstract We have analyzed and compared mitochondrial DNA variation of populations from the Near East and Africa and found a very high frequency of African lineages present in the Yemen Hadramawt: more than a third were of clear sub-Saharan origin. Other Arab populations carried ∼10% lineages of sub-Saharan origin, whereas non-Arab Near Eastern populations, by contrast, carried few or no such lineages, suggesting that gene flow has been preferentially into Arab populations. Several lines of evidence suggest that most of this gene flow probably occurred within the past ∼2,500 years. In contrast, there is little evidence for male-mediated gene flow from sub-Saharan Africa in Y-chromosome haplotypes in Arab populations, including the Hadramawt. Taken together, these results are consistent with substantial migration from eastern Africa into Arabia, at least in part as a result of the Arab slave trade, and mainly female assimilation into the Arabian population as a result of miscegenation and manumission. Abstract | | |