1
|
Liu J, Bitsue HK, Yang Z. Skin colour: A window into human phenotypic evolution and environmental adaptation. Mol Ecol 2024; 33:e17369. [PMID: 38713101 DOI: 10.1111/mec.17369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/13/2024] [Accepted: 04/17/2024] [Indexed: 05/08/2024]
Abstract
As modern humans ventured out of Africa and dispersed around the world, they faced novel environmental challenges that led to geographic adaptations including skin colour. Over the long history of human evolution, skin colour has changed dramatically, showing tremendous diversity across different geographical regions, for example, the majority of individuals from the expansive lands of Africa have darker skin, whereas the majority of people from Eurasia exhibit lighter skin. What adaptations did lighter skin confer upon modern humans as they migrated from Africa to Eurasia? What genetic mechanisms underlie the diversity of skin colour observed in different populations? In recent years, scientists have gradually gained a deeper understanding of the interactions between pigmentation gene and skin colour through population-based genomic studies of different groups around the world, particularly in East Asia and Africa. In this review, we summarize our current understanding of 26 skin colour-related pigmentation genes and 48 SNPs that influence skin colour. Important pigmentation genes across three major populations are described in detail: MFSD12, SLC24A5, PDPK1 and DDB1/CYB561A3/TMEM138 influence skin colour in African populations; OCA2, KITLG, SLC24A2, GNPAT and PAH are key to the evolution of skin pigmentation in East Asian populations; and SLC24A5, SLC45A2, TYR, TYRP1, ASIP, MC1R and IRF4 significantly contribute to the lightening of skin colour in European populations. We summarized recent findings in genomic studies of skin colour in populations that implicate diverse geographic environments, local adaptation among populations, gene flow and multi-gene interactions as factors influencing skin colour diversity.
Collapse
Affiliation(s)
- Jiuming Liu
- Tianjian Laboratory of Advanced Biomedical Sciences, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Habtom K Bitsue
- Tianjian Laboratory of Advanced Biomedical Sciences, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Zhaohui Yang
- Tianjian Laboratory of Advanced Biomedical Sciences, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| |
Collapse
|
2
|
Ragsdale AP, Weaver TD, Atkinson EG, Hoal EG, Möller M, Henn BM, Gravel S. A weakly structured stem for human origins in Africa. Nature 2023; 617:755-763. [PMID: 37198480 PMCID: PMC10208968 DOI: 10.1038/s41586-023-06055-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/05/2023] [Indexed: 05/19/2023]
Abstract
Despite broad agreement that Homo sapiens originated in Africa, considerable uncertainty surrounds specific models of divergence and migration across the continent1. Progress is hampered by a shortage of fossil and genomic data, as well as variability in previous estimates of divergence times1. Here we seek to discriminate among such models by considering linkage disequilibrium and diversity-based statistics, optimized for rapid, complex demographic inference2. We infer detailed demographic models for populations across Africa, including eastern and western representatives, and newly sequenced whole genomes from 44 Nama (Khoe-San) individuals from southern Africa. We infer a reticulated African population history in which present-day population structure dates back to Marine Isotope Stage 5. The earliest population divergence among contemporary populations occurred 120,000 to 135,000 years ago and was preceded by links between two or more weakly differentiated ancestral Homo populations connected by gene flow over hundreds of thousands of years. Such weakly structured stem models explain patterns of polymorphism that had previously been attributed to contributions from archaic hominins in Africa2-7. In contrast to models with archaic introgression, we predict that fossil remains from coexisting ancestral populations should be genetically and morphologically similar, and that only an inferred 1-4% of genetic differentiation among contemporary human populations can be attributed to genetic drift between stem populations. We show that model misspecification explains the variation in previous estimates of divergence times, and argue that studying a range of models is key to making robust inferences about deep history.
Collapse
Affiliation(s)
- Aaron P Ragsdale
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Timothy D Weaver
- Department of Anthropology, University of California, Davis, CA, USA
| | - Elizabeth G Atkinson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Eileen G Hoal
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, Stellenbosch University, Cape Town, South Africa
- South African Medical Research Council Centre for Tuberculosis Research, Stellenbosch University, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Marlo Möller
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, Stellenbosch University, Cape Town, South Africa
- South African Medical Research Council Centre for Tuberculosis Research, Stellenbosch University, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Brenna M Henn
- Department of Anthropology, University of California, Davis, CA, USA.
- Genome Center, University of California, Davis, CA, USA.
| | - Simon Gravel
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.
| |
Collapse
|
3
|
Kafeero HM, Ndagire D, Ocama P, Kato CD, Wampande E, Walusansa A, Kajumbula H, Kateete D, Ssenku JE, Sendagire H. Mapping hepatitis B virus genotypes on the African continent from 1997 to 2021: a systematic review with meta-analysis. Sci Rep 2023; 13:5723. [PMID: 37029173 PMCID: PMC10082212 DOI: 10.1038/s41598-023-32865-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 04/04/2023] [Indexed: 04/09/2023] Open
Abstract
Hepatitis B virus (HBV) has ten genotypes (A-J) and over 40 sub-genotypes based on the divergence of ≥ 8% and 4 to < 8% in the complete genome respectively. These genotypes and sub-genotypes influence the disease prognosis, response to therapy and route of viral transmission. Besides, infection with mixed genotypes and recombinant genotypes has also been reported. This study aimed at mapping the de novo genotypes and correlate them with the immigration trends in order to inform future research on the underlying reasons for the relative distribution of HBV genotypes from a large sample size pooled from many primary studies. Data was extracted from 59 full research articles obtained from Scopus, PubMed, EMBASE, Willy library, African Journal Online (AJOL) and Google Scholar. Studies that investigated the genotypes, sub-genotypes, mixed genotypes and recombinant were included. The Z-test and regression were used for the analysis. The study protocol is registered with PROSPERO under the registration number CRD42022300220. Overall, genotype E had the highest pooled prevalence significantly higher than all the other genotypes (P < 0.001). By region, genotype A posted the highest pooled prevalence in eastern and southern Africa, E in west Africa and D in north Africa (P < 0.0001). Regarding the emerging genotypes B and C on the African continent, genotype B was significantly higher in south Africa than C (P < 0.001). In contrast, genotype C was significantly higher in east Africa than west Africa (P < 0.0001). The A1 and D/E were the most diverse sub-genotypes and genotype mixtures respectively. Finally, we observed a general progressive decrease in the prevalence of predominant genotypes but a progressive increase in the less dominant by region. Historical and recent continental and intercontinental migrations can provide a plausible explanation for the HBV genotype distribution pattern on the African continent.
Collapse
Affiliation(s)
- Hussein Mukasa Kafeero
- Department of Medical Microbiology, College of Health Sciences, Makerere University, P. O Box 7062, Kampala, Uganda.
- Department of Medical Microbiology, Habib Medical School, Faculty of Health Sciences, Islamic University in Uganda, P. O Box 7689, Kampala, Uganda.
| | - Dorothy Ndagire
- Department of Plant Sciences, Microbiology and Biotechnology, College of Natural Sciences, Makerere University, P. O Box 7062, Kampala, Uganda
| | - Ponsiano Ocama
- Department of Medicine, College of Health Sciences, Makerere University, P. O Box 7062, Kampala, Uganda
| | - Charles Drago Kato
- Department of Biomolecular Resources and Biolab Sciences, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P. O Box 7062, Kampala, Uganda
| | - Eddie Wampande
- Department of Biomolecular Resources and Biolab Sciences, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P. O Box 7062, Kampala, Uganda
| | - Abdul Walusansa
- Department of Medical Microbiology, Habib Medical School, Faculty of Health Sciences, Islamic University in Uganda, P. O Box 7689, Kampala, Uganda
| | - Henry Kajumbula
- Department of Medical Microbiology, College of Health Sciences, Makerere University, P. O Box 7062, Kampala, Uganda
| | - David Kateete
- Department of Molecular Biology and Immunology, College of Health Sciences, Makerere University, P. O Box 7062, Kampala, Uganda
| | - Jamilu E Ssenku
- Department of Plant Sciences, Microbiology and Biotechnology, College of Natural Sciences, Makerere University, P. O Box 7062, Kampala, Uganda
| | - Hakim Sendagire
- Department of Medical Microbiology, College of Health Sciences, Makerere University, P. O Box 7062, Kampala, Uganda
- Department of Medical Microbiology, Habib Medical School, Faculty of Health Sciences, Islamic University in Uganda, P. O Box 7689, Kampala, Uganda
| |
Collapse
|
4
|
Swart Y, van Eeden G, Uren C, van der Spuy G, Tromp G, Möller M. GWAS in the southern African context. PLoS One 2022; 17:e0264657. [PMID: 36170230 PMCID: PMC9518849 DOI: 10.1371/journal.pone.0264657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 08/06/2022] [Indexed: 11/18/2022] Open
Abstract
Researchers would generally adjust for the possible confounding effect of population structure by considering global ancestry proportions or top principle components. Alternatively, researchers would conduct admixture mapping to increase the power to detect variants with an ancestry effect. This is sufficient in simple admixture scenarios, however, populations from southern Africa can be complex multi-way admixed populations. Duan et al. (2018) first described local ancestry adjusted allelic (LAAA) analysis as a robust method for discovering association signals, while producing minimal false positive hits. Their simulation study, however, was limited to a two-way admixed population. Realizing that their findings might not translate to other admixture scenarios, we simulated a three- and five-way admixed population to compare the LAAA model to other models commonly used in genome-wide association studies (GWAS). We found that, given our admixture scenarios, the LAAA model identifies the most causal variants in most of the phenotypes we tested across both the three-way and five-way admixed populations. The LAAA model also produced a high number of false positive hits which was potentially caused by the ancestry effect size that we assumed. Considering the extent to which the various models tested differed in their results and considering that the source of a given association is unknown, we recommend that researchers use multiple GWAS models when analysing populations with complex ancestry.
Collapse
Affiliation(s)
- Yolandi Swart
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Gerald van Eeden
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Caitlin Uren
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- Centre for Bioinformatics and Computational Biology, Stellenbosch University, Stellenbosch, South Africa
| | - Gian van der Spuy
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- SAMRC-SHIP South African Tuberculosis Bioinformatics Initiative (SATBBI), Center for Bioinformatics and Computational Biology, Cape Town, South Africa
| | - Gerard Tromp
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- Centre for Bioinformatics and Computational Biology, Stellenbosch University, Stellenbosch, South Africa
- SAMRC-SHIP South African Tuberculosis Bioinformatics Initiative (SATBBI), Center for Bioinformatics and Computational Biology, Cape Town, South Africa
| | - Marlo Möller
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- Centre for Bioinformatics and Computational Biology, Stellenbosch University, Stellenbosch, South Africa
- * E-mail:
| |
Collapse
|
5
|
van Eeden G, Uren C, Pless E, Mastoras M, van der Spuy GD, Tromp G, Henn BM, Möller M. The recombination landscape of the Khoe-San likely represents the upper limits of recombination divergence in humans. Genome Biol 2022; 23:172. [PMID: 35945619 PMCID: PMC9361568 DOI: 10.1186/s13059-022-02744-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 08/01/2022] [Indexed: 11/10/2022] Open
Abstract
Background Recombination maps are important resources for epidemiological and evolutionary analyses; however, there are currently no recombination maps representing any African population outside of those with West African ancestry. We infer the demographic history for the Nama, an indigenous Khoe-San population of southern Africa, and derive a novel, population-specific recombination map from the whole genome sequencing of 54 Nama individuals. We hypothesise that there are no publicly available recombination maps representative of the Nama, considering the deep population divergence and subsequent isolation of the Khoe-San from other African groups. Results We show that the recombination landscape of the Nama does not cluster with any continental groups with publicly available representative recombination maps. Finally, we use selection scans as an example of how fine-scale differences between the Nama recombination map and the combined Phase II HapMap recombination map can impact the outcome of selection scans. Conclusions Fine-scale differences in recombination can meaningfully alter the results of a selection scan. The recombination map we infer likely represents an upper bound on the extent of divergence we expect to see for a recombination map in humans and would be of interest to any researcher that wants to test the sensitivity of population genetic or GWAS analysis to recombination map input. Supplementary Information The online version contains supplementary material available at 10.1186/s13059-022-02744-5.
Collapse
Affiliation(s)
- Gerald van Eeden
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Caitlin Uren
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Centre for Bioinformatics and Computational Biology, Stellenbosch University, Stellenbosch, 7602, South Africa
| | - Evlyn Pless
- Department of Anthropology, Center for Population Biology and the Genome Center, University of California (UC) Davis, Davis, CA, USA
| | - Mira Mastoras
- Department of Anthropology, Center for Population Biology and the Genome Center, University of California (UC) Davis, Davis, CA, USA
| | - Gian D van der Spuy
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Centre for Bioinformatics and Computational Biology, Stellenbosch University, Stellenbosch, 7602, South Africa.,SAMRC-SHIP South African Tuberculosis Bioinformatics Initiative (SATBBI), Center for Bioinformatics and Computational Biology, Cape Town, South Africa
| | - Gerard Tromp
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Centre for Bioinformatics and Computational Biology, Stellenbosch University, Stellenbosch, 7602, South Africa.,SAMRC-SHIP South African Tuberculosis Bioinformatics Initiative (SATBBI), Center for Bioinformatics and Computational Biology, Cape Town, South Africa
| | - Brenna M Henn
- Department of Anthropology, Center for Population Biology and the Genome Center, University of California (UC) Davis, Davis, CA, USA
| | - Marlo Möller
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. .,Centre for Bioinformatics and Computational Biology, Stellenbosch University, Stellenbosch, 7602, South Africa.
| |
Collapse
|
6
|
Abstract
Joint phylogenetic analysis of ancient DNA (aDNA) with modern phylogenies is hampered by low sequence coverage and post-mortem deamination, often resulting in overconservative or incorrect assignment. We provide a new efficient likelihood-based workflow, pathPhynder, that takes advantage of all the polymorphic sites in the target sequence. This effectively evaluates the number of ancestral and derived alleles present on each branch and reports the most likely placement of an ancient sample in the phylogeny and a haplogroup assignment, together with alternatives and supporting evidence. To illustrate the application of pathPhynder, we show improved Y chromosome assignments for published aDNA sequences, using a newly compiled Y variation data set (120,908 markers from 2,014 samples) that significantly enhances Y haplogroup assignment for low coverage samples. We apply the method to all published male aDNA samples from Africa, giving new insights into ancient migrations and the relationships between ancient and modern populations. The same software can be used to place samples with large amounts of missing data into other large non-recombining phylogenies such as the mitochondrial tree.
Collapse
Affiliation(s)
- Rui Martiniano
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Bianca De Sanctis
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Pille Hallast
- Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Richard Durbin
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom
| |
Collapse
|
7
|
Vicente M, Lankheet I, Russell T, Hollfelder N, Coetzee V, Soodyall H, Jongh MD, Schlebusch CM. Male-biased migration from East Africa introduced pastoralism into southern Africa. BMC Biol 2021; 19:259. [PMID: 34872534 PMCID: PMC8650298 DOI: 10.1186/s12915-021-01193-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 11/12/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Hunter-gatherer lifestyles dominated the southern African landscape up to ~ 2000 years ago, when herding and farming groups started to arrive in the area. First, herding and livestock, likely of East African origin, appeared in southern Africa, preceding the arrival of the large-scale Bantu-speaking agro-pastoralist expansion that introduced West African-related genetic ancestry into the area. Present-day Khoekhoe-speaking Namaqua (or Nama in short) pastoralists show high proportions of East African admixture, linking the East African ancestry with Khoekhoe herders. Most other historical Khoekhoe populations have, however, disappeared over the last few centuries and their contribution to the genetic structure of present-day populations is not well understood. In our study, we analyzed genome-wide autosomal and full mitochondrial data from a population who trace their ancestry to the Khoekhoe-speaking Hessequa herders from the southern Cape region of what is now South Africa. RESULTS We generated genome-wide data from 162 individuals and mitochondrial DNA data of a subset of 87 individuals, sampled in the Western Cape Province, South Africa, where the Hessequa population once lived. Using available comparative data from Khoe-speaking and related groups, we aligned genetic date estimates and admixture proportions to the archaeological proposed dates and routes for the arrival of the East African pastoralists in southern Africa. We identified several Afro-Asiatic-speaking pastoralist groups from Ethiopia and Tanzania who share high affinities with the East African ancestry present in southern Africa. We also found that the East African pastoralist expansion was heavily male-biased, akin to a pastoralist migration previously observed on the genetic level in ancient Europe, by which Pontic-Caspian Steppe pastoralist groups represented by the Yamnaya culture spread across the Eurasian continent during the late Neolithic/Bronze Age. CONCLUSION We propose that pastoralism in southern Africa arrived through male-biased migration of an East African Afro-Asiatic-related group(s) who introduced new subsistence and livestock practices to local southern African hunter-gatherers. Our results add to the understanding of historical human migration and mobility in Africa, connected to the spread of food-producing and livestock practices.
Collapse
Affiliation(s)
- Mário Vicente
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
- Department of Archaeology and Classical Studies, Stockholm University, Stockholm, Sweden
- Centre for Palaeogenetics, Stockholm, Sweden
| | - Imke Lankheet
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | - Thembi Russell
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa
| | - Nina Hollfelder
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | - Vinet Coetzee
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Himla Soodyall
- Division of Human Genetics, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Academy of Science of South Africa, Pretoria, South Africa
| | - Michael De Jongh
- Department of Anthropology and Archaeology, University of South Africa, Pretoria, South Africa
| | - Carina M Schlebusch
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden.
- Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa.
- SciLife Lab, Uppsala, Sweden.
| |
Collapse
|
8
|
Campbell MC, Ranciaro A. Human adaptation, demography and cattle domestication: an overview of the complexity of lactase persistence in Africa. Hum Mol Genet 2021; 30:R98-R109. [PMID: 33847744 DOI: 10.1093/hmg/ddab027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/13/2021] [Accepted: 01/13/2021] [Indexed: 01/30/2023] Open
Abstract
Lactase persistence (LP) is a genetically-determined trait that is prevalent in African, European and Arab populations with a tradition of animal herding and milk consumption. To date, genetic analyses have identified several common variants that are associated with LP. Furthermore, data have indicated that these functional alleles likely have been maintained in pastoralist populations due to the action of recent selection, exemplifying the ongoing evolution of anatomically modern humans. Additionally, demographic history has also played a role in the geographic distribution of LP and associated alleles in Africa. In particular, the migration of ancestral herders and their subsequent admixture with local populations were integral to the spread of LP alleles and the culture of pastoralism across the continent. The timing of these demographic events was often correlated with known major environmental changes and/or the ability of domesticated cattle to resist/avoid infectious diseases. This review summarizes recent advances in our understanding of the genetic basis and evolutionary history of LP, as well as the factors that influenced the origin and spread of pastoralism in Africa.
Collapse
Affiliation(s)
- Michael C Campbell
- Department of Biology, Howard University, EE Just Hall Biology Building, 415 College Street NW, Washington, DC 20059, USA
| | - Alessia Ranciaro
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, 415 Curie Boulevard, Philadelphia, PA 19104, USA
| |
Collapse
|
9
|
Coutinho A, Malmström H, Edlund H, Henshilwood CS, van Niekerk KL, Lombard M, Schlebusch CM, Jakobsson M. Later Stone Age human hair from Vaalkrans Shelter, Cape Floristic Region of South Africa, reveals genetic affinity to Khoe groups. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 174:701-713. [PMID: 33539553 DOI: 10.1002/ajpa.24236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 12/09/2020] [Accepted: 12/20/2020] [Indexed: 11/09/2022]
Abstract
Previous studies show that the indigenous people of the southern Cape of South Africa were dramatically impacted by the arrival of European colonists starting ~400 years ago and their descendants are today mixed with Europeans and Asians. To gain insight on the occupants of the Vaalkrans Shelter located at the southernmost tip of Africa, we investigated the genetic make-up of an individual who lived there about 200 years ago. We further contextualize the genetic ancestry of this individual among prehistoric and current groups. From a hair sample excavated at the shelter, which was indirectly dated to about 200 years old, we sequenced the genome (1.01 times coverage) of a Later Stone Age individual. We analyzed the Vaalkrans genome together with genetic data from 10 ancient (pre-colonial) individuals from southern Africa spanning the last 2000 years. We show that the individual from Vaalkrans was a man who traced ~80% of his ancestry to local southern San hunter-gatherers and ~20% to a mixed East African-Eurasian source. This genetic make-up is similar to modern-day Khoekhoe individuals from the Northern Cape Province (South Africa) and Namibia, but in the southern Cape, the Vaalkrans man's descendants have likely been assimilated into mixed-ancestry "Coloured" groups. The Vaalkrans man's genome reveals that Khoekhoe pastoralist groups/individuals lived in the southern Cape as late as 200 years ago, without mixing with non-African colonists or Bantu-speaking farmers. Our findings are also consistent with the model of a Holocene pastoralist migration, originating in Eastern Africa, shaping the genomic landscape of historic and current southern African populations.
Collapse
Affiliation(s)
- Alexandra Coutinho
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | - Helena Malmström
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden.,Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa
| | - Hanna Edlund
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | - Christopher S Henshilwood
- SFF Centre for Early Sapiens Behaviour (SapienCE), University of Bergen, Bergen, Norway.,Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
| | - Karen L van Niekerk
- SFF Centre for Early Sapiens Behaviour (SapienCE), University of Bergen, Bergen, Norway
| | - Marlize Lombard
- Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa
| | - Carina M Schlebusch
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden.,Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa.,Science for Life Laboratory, Uppsala, Sweden
| | - Mattias Jakobsson
- Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden.,Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa.,Science for Life Laboratory, Uppsala, Sweden
| |
Collapse
|
10
|
|
11
|
Naidoo T, Xu J, Vicente M, Malmström H, Soodyall H, Jakobsson M, Schlebusch CM. Y-Chromosome Variation in Southern African Khoe-San Populations Based on Whole-Genome Sequences. Genome Biol Evol 2020; 12:1031-1039. [PMID: 32697300 PMCID: PMC7375190 DOI: 10.1093/gbe/evaa098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/12/2020] [Indexed: 12/30/2022] Open
Abstract
Although the human Y chromosome has effectively shown utility in uncovering facets of human evolution and population histories, the ascertainment bias present in early Y-chromosome variant data sets limited the accuracy of diversity and TMRCA estimates obtained from them. The advent of next-generation sequencing, however, has removed this bias and allowed for the discovery of thousands of new variants for use in improving the Y-chromosome phylogeny and computing estimates that are more accurate. Here, we describe the high-coverage sequencing of the whole Y chromosome in a data set of 19 male Khoe-San individuals in comparison with existing whole Y-chromosome sequence data. Due to the increased resolution, we potentially resolve the source of haplogroup B-P70 in the Khoe-San, and reconcile recently published haplogroup A-M51 data with the most recent version of the ISOGG Y-chromosome phylogeny. Our results also improve the positioning of tentatively placed new branches of the ISOGG Y-chromosome phylogeny. The distribution of major Y-chromosome haplogroups in the Khoe-San and other African groups coincide with the emerging picture of African demographic history; with E-M2 linked to the agriculturalist Bantu expansion, E-M35 linked to pastoralist eastern African migrations, B-M112 linked to earlier east-south gene flow, A-M14 linked to shared ancestry with central African rainforest hunter-gatherers, and A-M51 potentially unique to the Khoe-San.
Collapse
Affiliation(s)
- Thijessen Naidoo
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Sweden
- Department of Archaeology and Classical Studies, Stockholm University, Sweden
- Science for Life Laboratory, Uppsala, Sweden
- Centre for Palaeogenetics, Stockholm, Sweden
| | - Jingzi Xu
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Sweden
| | - Mário Vicente
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Sweden
| | - Helena Malmström
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Sweden
- Palaeo-Research Institute, University of Johannesburg, Auckland Park, South Africa
| | - Himla Soodyall
- Division of Human Genetics, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- National Health Laboratory Service, Johannesburg, South Africa
- Academy of Science of South Africa
| | - Mattias Jakobsson
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Sweden
- Science for Life Laboratory, Uppsala, Sweden
- Palaeo-Research Institute, University of Johannesburg, Auckland Park, South Africa
| | - Carina M Schlebusch
- Human Evolution, Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Sweden
- Science for Life Laboratory, Uppsala, Sweden
- Palaeo-Research Institute, University of Johannesburg, Auckland Park, South Africa
| |
Collapse
|
12
|
Vicente M, Schlebusch CM. African population history: an ancient DNA perspective. Curr Opin Genet Dev 2020; 62:8-15. [DOI: 10.1016/j.gde.2020.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 11/30/2022]
|
13
|
Wang K, Goldstein S, Bleasdale M, Clist B, Bostoen K, Bakwa-Lufu P, Buck LT, Crowther A, Dème A, McIntosh RJ, Mercader J, Ogola C, Power RC, Sawchuk E, Robertshaw P, Wilmsen EN, Petraglia M, Ndiema E, Manthi FK, Krause J, Roberts P, Boivin N, Schiffels S. Ancient genomes reveal complex patterns of population movement, interaction, and replacement in sub-Saharan Africa. SCIENCE ADVANCES 2020; 6:eaaz0183. [PMID: 32582847 PMCID: PMC7292641 DOI: 10.1126/sciadv.aaz0183] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 04/15/2020] [Indexed: 05/25/2023]
Abstract
Africa hosts the greatest human genetic diversity globally, but legacies of ancient population interactions and dispersals across the continent remain understudied. Here, we report genome-wide data from 20 ancient sub-Saharan African individuals, including the first reported ancient DNA from the DRC, Uganda, and Botswana. These data demonstrate the contraction of diverse, once contiguous hunter-gatherer populations, and suggest the resistance to interaction with incoming pastoralists of delayed-return foragers in aquatic environments. We refine models for the spread of food producers into eastern and southern Africa, demonstrating more complex trajectories of admixture than previously suggested. In Botswana, we show that Bantu ancestry post-dates admixture between pastoralists and foragers, suggesting an earlier spread of pastoralism than farming to southern Africa. Our findings demonstrate how processes of migration and admixture have markedly reshaped the genetic map of sub-Saharan Africa in the past few millennia and highlight the utility of combined archaeological and archaeogenetic approaches.
Collapse
Affiliation(s)
- Ke Wang
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Steven Goldstein
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Madeleine Bleasdale
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Bernard Clist
- UGent Centre for Bantu Studies, Department of Languages and Cultures, Ghent University, Ghent, Belgium
- Institut des Mondes Africains, Paris, France
| | - Koen Bostoen
- UGent Centre for Bantu Studies, Department of Languages and Cultures, Ghent University, Ghent, Belgium
| | - Paul Bakwa-Lufu
- Institut des Musées Nationaux du Congo, Kinshasa, Democratic Republic of Congo
| | - Laura T. Buck
- Department of Archaeology, University of Cambridge, Cambridge, UK
- Department of Anthropology, University of California, Davis, Davis, CA, USA
| | - Alison Crowther
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
- School of Social Science, University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Alioune Dème
- Department of History, Cheikh Anta Diop University, Dakar, Senegal
| | | | - Julio Mercader
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
- Department of Archaeology and Anthropology, University of Calgary, Calgary, Alberta, Canada
| | - Christine Ogola
- Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya
| | - Robert C. Power
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
- Institute for Pre- and Protohistoric Archaeology and Archaeology of the Roman Provinces, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Elizabeth Sawchuk
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
- Department of Anthropology, Stony Brook University, Stony Brook, NY, USA
| | - Peter Robertshaw
- Department of Anthropology, California State University, San Bernardino, San Bernardino, CA, USA
| | - Edwin N. Wilmsen
- University of Texas-Austin, Austin, TX, USA
- Witwatersrand University, Johannesburg, Republic of South Africa
| | - Michael Petraglia
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
- School of Social Science, University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
- Department of Anthropology, Smithsonian Institution, Washington, DC, USA
| | - Emmanuel Ndiema
- Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya
| | | | - Johannes Krause
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Patrick Roberts
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
- School of Social Science, University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Nicole Boivin
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
- School of Social Science, University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
- Department of Archaeology and Anthropology, University of Calgary, Calgary, Alberta, Canada
- Department of Anthropology, Smithsonian Institution, Washington, DC, USA
| | - Stephan Schiffels
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| |
Collapse
|
14
|
Miller JM, Sawchuk EA. Ostrich eggshell bead diameter in the Holocene: Regional variation with the spread of herding in eastern and southern Africa. PLoS One 2019; 14:e0225143. [PMID: 31774851 PMCID: PMC6880992 DOI: 10.1371/journal.pone.0225143] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 10/29/2019] [Indexed: 11/23/2022] Open
Abstract
Despite their ubiquity in Holocene African archaeological assemblages, ostrich eggshell (OES) beads are rarely studied in detail. An exception is in southern Africa, where there is a proposed relationship between OES bead diameter and the arrival of herding ~2000 years before present. In 1987, Leon Jacobson first observed that beads from forager sites in Namibia tended to be smaller than those associated with herder sites. Studies examining bead size around the Western Cape have generally confirmed Jacobson's findings, though the driving forces of the diameter change remain unknown. Since this time, diameter has become an informal way of distinguishing forager and herder assemblages in southern Africa, but no large-scale studies of OES bead variation have been undertaken. Here we present an expanded analysis of Holocene OES bead diameters from southern, and for the first time, eastern Africa. Results reveal distinct patterns in OES bead size over time, reflecting different local dynamics associated with the spread of herding. In southern Africa, OES diameters display low variability and smaller absolute size through time. While larger beads begin to appear <2000 years ago, most beads in our study remained smaller. In contrast, eastern African OES bead diameters are consistently larger over the last 10,000 years and show no appreciable size change with the introduction of herding. Notably, larger beads thought to be associated with herders in southern Africa fall within the range of eastern African beads, indicating a potential connection between these regions in the Late Holocene consistent with genetic findings. Regional differences in bead size are subtle, on the order of millimeters, yet offer a potentially important line of evidence for investigating the spread of herding in sub-Saharan Africa. In order to understand the meaning of these changes, we encourage additional studies of OES bead assemblages and urge researchers to report individual bead diameters, rather than averages by level.
Collapse
Affiliation(s)
- Jennifer M. Miller
- Department of Anthropology, University of Alberta, Edmonton, Canada
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Elizabeth A. Sawchuk
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
- Department of Anthropology, Stony Brook University, New York, United States of America
| |
Collapse
|
15
|
Prendergast ME, Lipson M, Sawchuk EA, Olalde I, Ogola CA, Rohland N, Sirak KA, Adamski N, Bernardos R, Broomandkhoshbacht N, Callan K, Culleton BJ, Eccles L, Harper TK, Lawson AM, Mah M, Oppenheimer J, Stewardson K, Zalzala F, Ambrose SH, Ayodo G, Gates HL, Gidna AO, Katongo M, Kwekason A, Mabulla AZP, Mudenda GS, Ndiema EK, Nelson C, Robertshaw P, Kennett DJ, Manthi FK, Reich D. Ancient DNA reveals a multistep spread of the first herders into sub-Saharan Africa. Science 2019; 365:science.aaw6275. [PMID: 31147405 DOI: 10.1126/science.aaw6275] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 05/13/2019] [Indexed: 12/31/2022]
Abstract
How food production first entered eastern Africa ~5000 years ago and the extent to which people moved with livestock is unclear. We present genome-wide data from 41 individuals associated with Later Stone Age, Pastoral Neolithic (PN), and Iron Age contexts in what are now Kenya and Tanzania to examine the genetic impacts of the spreads of herding and farming. Our results support a multiphase model in which admixture between northeastern African-related peoples and eastern African foragers formed multiple pastoralist groups, including a genetically homogeneous PN cluster. Additional admixture with northeastern and western African-related groups occurred by the Iron Age. These findings support several movements of food producers while rejecting models of minimal admixture with foragers and of genetic differentiation between makers of distinct PN artifacts.
Collapse
Affiliation(s)
- Mary E Prendergast
- Division of Humanities, Saint Louis University, 28003 Madrid, Spain. .,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Mark Lipson
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
| | - Elizabeth A Sawchuk
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11790, USA.
| | - Iñigo Olalde
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Christine A Ogola
- Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya
| | - Nadin Rohland
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Kendra A Sirak
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Nicole Adamski
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Rebecca Bernardos
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Nasreen Broomandkhoshbacht
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Kimberly Callan
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Brendan J Culleton
- Institutes for Energy and the Environment, Pennsylvania State University, University Park, PA 16802, USA
| | - Laurie Eccles
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA
| | - Thomas K Harper
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA
| | - Ann Marie Lawson
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Matthew Mah
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Jonas Oppenheimer
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Kristin Stewardson
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Fatma Zalzala
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Stanley H Ambrose
- Department of Anthropology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - George Ayodo
- Department of Public and Community Health, School of Health Sciences, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya
| | - Henry Louis Gates
- Hutchins Center for African and African American Research, Harvard University, Cambridge, MA 02138, USA
| | | | | | | | | | | | - Emmanuel K Ndiema
- Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya
| | - Charles Nelson
- Academy for Lifelong Learning, Western Washington University, Bellingham, WA 98225, USA
| | - Peter Robertshaw
- Department of Anthropology, California State University, San Bernardino, CA 92407, USA
| | - Douglas J Kennett
- Department of Anthropology, University of California, Santa Barbara, CA 93106, USA
| | - Fredrick K Manthi
- Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya
| | - David Reich
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA. .,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| |
Collapse
|
16
|
A dispersal of Homo sapiens from southern to eastern Africa immediately preceded the out-of-Africa migration. Sci Rep 2019; 9:4728. [PMID: 30894612 PMCID: PMC6426877 DOI: 10.1038/s41598-019-41176-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/19/2019] [Indexed: 01/08/2023] Open
Abstract
Africa was the birth-place of Homo sapiens and has the earliest evidence for symbolic behaviour and complex technologies. The best-attested early flowering of these distinctive features was in a glacial refuge zone on the southern coast 100–70 ka, with fewer indications in eastern Africa until after 70 ka. Yet it was eastern Africa, not the south, that witnessed the first major demographic expansion, ~70–60 ka, which led to the peopling of the rest of the world. One possible explanation is that important cultural traits were transmitted from south to east at this time. Here we identify a mitochondrial signal of such a dispersal soon after ~70 ka – the only time in the last 200,000 years that humid climate conditions encompassed southern and tropical Africa. This dispersal immediately preceded the out-of-Africa expansions, potentially providing the trigger for these expansions by transmitting significant cultural elements from the southern African refuge.
Collapse
|
17
|
Rapid evolution of a skin-lightening allele in southern African KhoeSan. Proc Natl Acad Sci U S A 2018; 115:13324-13329. [PMID: 30530665 DOI: 10.1073/pnas.1801948115] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Skin pigmentation is under strong directional selection in northern European and Asian populations. The indigenous KhoeSan populations of far southern Africa have lighter skin than other sub-Saharan African populations, potentially reflecting local adaptation to a region of Africa with reduced UV radiation. Here, we demonstrate that a canonical Eurasian skin pigmentation gene, SLC24A5, was introduced to southern Africa via recent migration and experienced strong adaptive evolution in the KhoeSan. To reconstruct the evolution of skin pigmentation, we collected phenotypes from over 400 ≠Khomani San and Nama individuals and high-throughput sequenced candidate pigmentation genes. The derived causal allele in SLC24A5, p.Ala111Thr, significantly lightens basal skin pigmentation in the KhoeSan and explains 8 to 15% of phenotypic variance in these populations. The frequency of this allele (33 to 53%) is far greater than expected from colonial period European gene flow; however, the most common derived haplotype is identical among European, eastern African, and KhoeSan individuals. Using four-population demographic simulations with selection, we show that the allele was introduced into the KhoeSan only 2,000 y ago via a back-to-Africa migration and then experienced a selective sweep (s = 0.04 to 0.05 in ≠Khomani and Nama). The SLC24A5 locus is both a rare example of intense, ongoing adaptation in very recent human history, as well as an adaptive gene flow at a pigmentation locus in humans.
Collapse
|
18
|
Montinaro F, Capelli C. The evolutionary history of Southern Africa. Curr Opin Genet Dev 2018; 53:157-164. [PMID: 30522870 DOI: 10.1016/j.gde.2018.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 10/12/2018] [Accepted: 11/06/2018] [Indexed: 01/15/2023]
Abstract
The genomic variability of Southern African groups is characterized by an exceptional degree of diversity, which is the result of long-term local evolutionary history, migrations and gene-flow. Over the last few years several investigations have identified and described signatures related to these processes, revealing how ancient and more recent events have shaped the structure and ancestry composition of local populations. Here we discuss recent insights into the genetic history of the Southernmost part of the African continent provided by the analysis of modern and ancient genomes. Future work is expected to clarify the population dynamics associated with the emergence of Homo sapiens across Africa and the details of the process of dispersion and admixture associated with the arrival of Bantu-speaking groups in the region.
Collapse
Affiliation(s)
- Francesco Montinaro
- Department of Zoology, University of Oxford, UK; Estonian Biocentre, Institute of Genomics, University of Tartu, Tartu, Estonia
| | | |
Collapse
|
19
|
Oliveira S, Hübner A, Fehn AM, Aço T, Lages F, Pakendorf B, Stoneking M, Rocha J. The role of matrilineality in shaping patterns of Y chromosome and mtDNA sequence variation in southwestern Angola. Eur J Hum Genet 2018; 27:475-483. [PMID: 30467412 DOI: 10.1038/s41431-018-0304-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/25/2018] [Accepted: 11/01/2018] [Indexed: 11/09/2022] Open
Abstract
Southwestern Angola is a region characterized by contact between indigenous foragers and incoming food-producers, involving genetic and cultural exchanges between peoples speaking Kx'a, Khoe-Kwadi, and Bantu languages. Although present-day Bantu speakers share a patrilocal residence pattern and matrilineal principle of clan and group membership, a highly stratified social setting divides dominant pastoralists from marginalized groups that subsist on alternative strategies and have previously been thought to have pre-Bantu origins. Here, we compare new high-resolution sequence data from 2.3 Mb of the male-specific region of the Y chromosome (MSY) from 170 individuals with previously reported mitochondrial DNA (mtDNA) genomes, to investigate the population history of seven representative southwestern Angolan groups (Himba, Kuvale, Kwisi, Kwepe, Twa, Tjimba, !Xun), and to study the causes and consequences of sex-biased processes in their genetic variation. We found no clear link between the formerly Kwadi-speaking Kwepe and pre-Bantu eastern African migrants, and no pre-Bantu MSY lineages among Bantu-speaking groups, except for small amounts of "Khoisan" introgression. We therefore propose that irrespective of their subsistence strategies, all Bantu-speaking groups of the area share a male Bantu origin. Additionally, we show that in Bantu-speaking groups, the levels of among-group and between-group variation are higher for mtDNA than for MSY. These results, together with our previous demonstration that the matriclanic systems of southwestern Angolan Bantu groups are genealogically consistent, suggest that matrilineality strongly enhances both female population sizes and interpopulation mtDNA variation.
Collapse
Affiliation(s)
- Sandra Oliveira
- CIBIO/InBIO: Research Center in Biodiversity and Genetic Resources, 4485-661, Vairão, Portugal. .,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4169-007, Porto, Portugal.
| | - Alexander Hübner
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103, Leipzig, Germany
| | - Anne-Maria Fehn
- CIBIO/InBIO: Research Center in Biodiversity and Genetic Resources, 4485-661, Vairão, Portugal.,Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, 00745, Jena, Germany.,Institute for African Studies, Goethe University, 60323, Frankfurt, Germany
| | - Teresa Aço
- Centro de Estudos do Deserto (CEDO), Namibe, Angola
| | - Fernanda Lages
- ISCED/Huíla-Instituto Superior de Ciências da Educação, Lubango, Angola
| | - Brigitte Pakendorf
- Laboratoire Dynamique du Langage, UMR5596, CNRS & Univ Lyon, 69007, Lyon, France
| | - Mark Stoneking
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103, Leipzig, Germany
| | - Jorge Rocha
- CIBIO/InBIO: Research Center in Biodiversity and Genetic Resources, 4485-661, Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4169-007, Porto, Portugal.,ISCED/Huíla-Instituto Superior de Ciências da Educação, Lubango, Angola
| |
Collapse
|
20
|
Documented composition of cadaveric skeletal remains in the University of Cape Town Human Skeletal Collection, South Africa. Forensic Sci Int 2018; 294:219.e1-219.e7. [PMID: 30446323 DOI: 10.1016/j.forsciint.2018.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/03/2018] [Accepted: 10/11/2018] [Indexed: 11/22/2022]
Abstract
The University of Cape Town Human Skeletal Collection is one of the oldest documented skeletal collections in South Africa. The skeletal remains housed in this collection have been used for a variety of studies, but no complete description of the composition of the collection currently exists in the published literature. The aim of this study is to provide a detailed description of the composition of the cadaveric collection to encourage use thereof by national and international researchers. As of 2016, the collection contained the skeletal remains of 343 cadaveric individuals, 163 of which have mostly complete crania and postcrania. The male to female ratio of the collection is approximately 3:2. White individuals constitute 70% of the collection, with smaller contributions by individuals of the Black and Coloured population groups. Most of the individuals in the collection were 60-90 years old at death, though the mean age of the Black and Coloured groups was much lower, likely due to differences in origin of the cadavers received by the Faculty of Health Sciences. The most common reported cause of death in the collection was circulatory disease, followed by neoplasms and respiratory disease. Despite differences in the composition of this collection and the provincial and national demographic profiles, the collection remains an invaluable resource for training and research in a wide variety of scientific fields.
Collapse
|
21
|
Bajić V, Barbieri C, Hübner A, Güldemann T, Naumann C, Gerlach L, Berthold F, Nakagawa H, Mpoloka SW, Roewer L, Purps J, Stoneking M, Pakendorf B. Genetic structure and sex-biased gene flow in the history of southern African populations. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 167:656-671. [PMID: 30192370 PMCID: PMC6667921 DOI: 10.1002/ajpa.23694] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 07/13/2018] [Accepted: 07/15/2018] [Indexed: 12/31/2022]
Abstract
Objectives We investigated the genetic history of southern African populations with a special focus on their paternal history. We reexamined previous claims that the Y‐chromosome haplogroup E1b1b (E‐M293) was brought to southern Africa by pastoralists from eastern Africa, and investigated patterns of sex‐biased gene flow in southern Africa. Materials and methods We analyzed previously published complete mtDNA genome sequences and ∼900 kb of NRY sequences from 23 populations from Namibia, Botswana, and Zambia, as well as haplogroup frequencies from a large sample of southern African populations and 23 newly genotyped Y‐linked STR loci for samples assigned to haplogroup E1b1b. Results Our results support an eastern African origin for Y‐chromosome haplogroup E1b1b (E‐M293); however, its current distribution in southern Africa is not strongly associated with pastoralism, suggesting more complex demographic events and/or changes in subsistence practices in this region. The Bantu expansion in southern Africa had a notable genetic impact and was probably a rapid, male‐dominated expansion. Our finding of a significant increase in the intensity of the sex‐biased gene flow from north to south may reflect changes in the social dynamics between Khoisan and Bantu groups over time. Conclusions Our study shows that the population history of southern Africa has been complex, with different immigrating groups mixing to different degrees with the autochthonous populations. The Bantu expansion led to heavily sex‐biased admixture as a result of interactions between Khoisan females and Bantu males, with a geographic gradient which may reflect changes in the social dynamics between Khoisan and Bantu groups over time.
Collapse
Affiliation(s)
- Vladimir Bajić
- Department of Evolutionary Genetics, MPI for Evolutionary Anthropology, Leipzig, Germany
| | - Chiara Barbieri
- Department of Linguistic and Cultural Evolution, MPI for the Science of Human History, Jena, Germany.,Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Alexander Hübner
- Department of Evolutionary Genetics, MPI for Evolutionary Anthropology, Leipzig, Germany
| | - Tom Güldemann
- Department of Linguistic and Cultural Evolution, MPI for the Science of Human History, Jena, Germany.,Institute of Asian and African Studies, Humboldt University, Berlin, Germany
| | - Christfried Naumann
- Institute of Asian and African Studies, Humboldt University, Berlin, Germany
| | - Linda Gerlach
- Department of Human Behavior, Ecology and Culture, MPI for Evolutionary Anthropology, Leipzig, Germany
| | - Falko Berthold
- Max Planck Research Group on Comparative Population Linguistics, MPI for Evolutionary Anthropology, Leipzig, Germary
| | - Hirosi Nakagawa
- Institute of Global Studies, Tokyo University of Foreign Studies, Tokyo, Japan
| | - Sununguko W Mpoloka
- Department of Biological Sciences, University of Botswana, Gaborone, Botswana
| | - Lutz Roewer
- Charité - Universitätsmedizin Berlin, Department of Forensic Genetics, Institute of Legal Medicine and Forensic Sciences, Berlin, Germany
| | - Josephine Purps
- Charité - Universitätsmedizin Berlin, Department of Forensic Genetics, Institute of Legal Medicine and Forensic Sciences, Berlin, Germany
| | - Mark Stoneking
- Department of Evolutionary Genetics, MPI for Evolutionary Anthropology, Leipzig, Germany
| | - Brigitte Pakendorf
- Laboratoire «Dynamique du Langage», CNRS & Université de Lyon, Lyon, France
| |
Collapse
|
22
|
Maass P, Friedling LJ. Morphometric Analysis of the Neurocranium in an Adult South African Cadaveric Sample. J Forensic Sci 2018; 64:367-374. [PMID: 30129084 DOI: 10.1111/1556-4029.13878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/05/2018] [Accepted: 07/05/2018] [Indexed: 11/27/2022]
Abstract
Craniometric studies of South Africans yield high accuracies of sex and ancestry classification, but most assess only inter-group variation of Black and White individuals, excluding the highly heterogeneous Colored group, which constitute a significant proportion of the population. This study applied a geometric morphometric approach to the neurocrania of 774 Black, Colored, and White individuals to assess sex and ancestry estimation accuracy based on the detected morphological variation. Accuracies of 70% and 83% were achieved for sex and ancestry, respectively, with ancestry-related variation contributing the largest proportion of overall observed variation. Even when comparing the closely related Black and Colored groups, relatively high accuracies were obtained. It is thus recommended that a similar approach be used to develop a contemporary three-dimensional database, which can be used to objectively, reliably, and accurately classify unknown remains in the South African forensic context.
Collapse
Affiliation(s)
- Petra Maass
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town, 7925, South Africa.,Department of Basic Medical Sciences, Faculty of Health Sciences, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein, 9300, South Africa
| | - Louise Jacqui Friedling
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town, 7925, South Africa
| |
Collapse
|
23
|
Cabrera VM, Marrero P, Abu-Amero KK, Larruga JM. Carriers of mitochondrial DNA macrohaplogroup L3 basal lineages migrated back to Africa from Asia around 70,000 years ago. BMC Evol Biol 2018; 18:98. [PMID: 29921229 PMCID: PMC6009813 DOI: 10.1186/s12862-018-1211-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 06/05/2018] [Indexed: 11/15/2022] Open
Abstract
Background The main unequivocal conclusion after three decades of phylogeographic mtDNA studies is the African origin of all extant modern humans. In addition, a southern coastal route has been argued for to explain the Eurasian colonization of these African pioneers. Based on the age of macrohaplogroup L3, from which all maternal Eurasian and the majority of African lineages originated, the out-of-Africa event has been dated around 60-70 kya. On the opposite side, we have proposed a northern route through Central Asia across the Levant for that expansion and, consistent with the fossil record, we have dated it around 125 kya. To help bridge differences between the molecular and fossil record ages, in this article we assess the possibility that mtDNA macrohaplogroup L3 matured in Eurasia and returned to Africa as basal L3 lineages around 70 kya. Results The coalescence ages of all Eurasian (M,N) and African (L3 ) lineages, both around 71 kya, are not significantly different. The oldest M and N Eurasian clades are found in southeastern Asia instead near of Africa as expected by the southern route hypothesis. The split of the Y-chromosome composite DE haplogroup is very similar to the age of mtDNA L3. An Eurasian origin and back migration to Africa has been proposed for the African Y-chromosome haplogroup E. Inside Africa, frequency distributions of maternal L3 and paternal E lineages are positively correlated. This correlation is not fully explained by geographic or ethnic affinities. This correlation rather seems to be the result of a joint and global replacement of the old autochthonous male and female African lineages by the new Eurasian incomers. Conclusions These results are congruent with a model proposing an out-of-Africa migration into Asia, following a northern route, of early anatomically modern humans carrying pre-L3 mtDNA lineages around 125 kya, subsequent diversification of pre-L3 into the basal lineages of L3, a return to Africa of Eurasian fully modern humans around 70 kya carrying the basal L3 lineages and the subsequent diversification of Eurasian-remaining L3 lineages into the M and N lineages in the outside-of-Africa context, and a second Eurasian global expansion by 60 kya, most probably, out of southeast Asia. Climatic conditions and the presence of Neanderthals and other hominins might have played significant roles in these human movements. Moreover, recent studies based on ancient DNA and whole-genome sequencing are also compatible with this hypothesis. Electronic supplementary material The online version of this article (10.1186/s12862-018-1211-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Vicente M Cabrera
- Departamento de Genética, Facultad de Biología, Universidad de La Laguna, E-38271 La Laguna, Tenerife, Spain.
| | - Patricia Marrero
- Research Support General Service, E-38271, La Laguna, Tenerife, Spain
| | - Khaled K Abu-Amero
- Glaucoma Research Chair, Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.,Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Jose M Larruga
- Departamento de Genética, Facultad de Biología, Universidad de La Laguna, E-38271 La Laguna, Tenerife, Spain
| |
Collapse
|
24
|
Morphometric analysis of the humerus in an adult South African cadaveric sample. Forensic Sci Int 2018; 289:451.e1-451.e9. [PMID: 29895429 DOI: 10.1016/j.forsciint.2018.04.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 01/15/2018] [Accepted: 04/20/2018] [Indexed: 11/23/2022]
Abstract
Recent studies using geometric morphometrics have shown that estimations of demographic parameters can be made using skeletal elements previously not thought useful for such purposes. This study used geometric morphometrics to assess humeral morphological variation in an adult South African sample, and evaluated the accuracy of sex and ancestry estimations based on this variation. Humeri of 1046 adult South African individuals (464 females, 582 males) were digitized. Data sets were rotated and scaled to a common centroid using Generalized Procrustes Analysis. Mean centroid sizes between groups were compared using parametric tests, while morphological variation was evaluated using multivariate analyses. Discriminant Function Analysis coupled with leave-one-out cross-validation tests were used to assess the reliability of sex and ancestry classifications based on this variation. Male humeri were relatively larger and presented with morphological features indicative of larger muscle mass and smaller carrying angles than females. White individuals had relatively larger but morphologically less robust humeri than Black or Coloured individuals, likely a reflection of both genetic and socio-economic differences between the groups as enforced under Apartheid law. When sex and ancestry were assessed together, similar variations were detected than when either parameter was individually assessed. Classification accuracy was relatively low when sex was independently assessed (73.3%), but increased when considered in conjunction with ancestry, indicating greater variation between-groups (ancestry) than within-groups. Ancestry estimation accuracies exceeded 80%, even for the highly diverse Coloured group. Classification accuracies of sex-ancestry groups all exceeded 76%. These results show that humerus morphological variation is present and may be used to estimate parameters, such as sex and ancestry, even in complex groups such as the Coloured sample of this study.
Collapse
|
25
|
Shriner D, Tekola-Ayele F, Adeyemo A, Rotimi CN. Genetic Ancestry of Hadza and Sandawe Peoples Reveals Ancient Population Structure in Africa. Genome Biol Evol 2018; 10:875-882. [PMID: 29608727 PMCID: PMC5863221 DOI: 10.1093/gbe/evy051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2018] [Indexed: 12/19/2022] Open
Abstract
The Hadza and Sandawe populations in present-day Tanzania speak languages containing click sounds and therefore thought to be distantly related to southern African Khoisan languages. We analyzed genome-wide genotype data for individuals sampled from the Hadza and Sandawe populations in the context of a global data set of 3,528 individuals from 163 ethno-linguistic groups. We found that Hadza and Sandawe individuals share ancestry distinct from and most closely related to Omotic ancestry; share Khoisan ancestry with populations such as ≠Khomani, Karretjie, and Ju/'hoansi in southern Africa; share Niger-Congo ancestry with populations such as Yoruba from Nigeria and Luhya from Kenya, consistent with migration associated with the Bantu Expansion; and share Cushitic ancestry with Somali, multiple Ethiopian populations, the Maasai population in Kenya, and the Nama population in Namibia. We detected evidence for low levels of Arabian, Nilo-Saharan, and Pygmy ancestries in a minority of individuals. Our results indicate that west Eurasian ancestry in eastern Africa is more precisely the Arabian parent of Cushitic ancestry. Relative to the Out-of-Africa migrations, Hadza ancestry emerged early whereas Sandawe ancestry emerged late.
Collapse
Affiliation(s)
- Daniel Shriner
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, Bethesda, Maryland
| | - Fasil Tekola-Ayele
- Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland
| | - Adebowale Adeyemo
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, Bethesda, Maryland
| | - Charles N Rotimi
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, Bethesda, Maryland
| |
Collapse
|
26
|
Oliveira S, Fehn AM, Aço T, Lages F, Gayà-Vidal M, Pakendorf B, Stoneking M, Rocha J. Matriclans shape populations: Insights from the Angolan Namib Desert into the maternal genetic history of southern Africa. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 165:518-535. [PMID: 29313877 DOI: 10.1002/ajpa.23378] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/17/2017] [Accepted: 12/09/2017] [Indexed: 11/10/2022]
Abstract
OBJECTIVES Southern Angola is a poorly studied region, inhabited by populations that have been associated with different migratory movements into southern Africa. Apart from Kx'a-speaking San foragers and Bantu-speaking pastoralists, ethnographic and linguistic studies have suggested the existence of an enigmatic array of pre-Bantu communities, like the Kwepe (formerly Khoe-Kwadi speakers), Twa and Kwisi. Here, we evaluate previous peopling hypotheses by assessing the relationships between different southern Angolan populations, based on newly collected linguistic data and complete mtDNA genomes. MATERIALS AND METHODS We analyzed 295 complete mtDNA genomes and linguistic data from seven groups from the Namib Desert (Himba, Kuvale, Tjimba, Twa, Kwisi, Kwepe) and Kunene Province (!Xun), placing special emphasis on the evaluation of the genealogical consistency of the matriclanic system that characterizes most of these groups. RESULTS We found that the maternal genetic structure of all groups from the Namib Desert was strongly shaped by the consistency of their matriclanic system. The tracking of the maternal heritage enhanced population differentiation by genetic drift and is likely to have caused the divergent mtDNA profiles of the Kwepe, Twa, and Kwisi, who probably formed a single population within the spectrum of Bantu genetic variation. Model-based analyses further suggest that the dominant pastoral groups Kuvale and Himba may be grouped into a Bantu proto-population which also included the ancestors of present-day Tjimba and Herero, as well as the Khoe-Kwadi speaking Damara foragers from Namibia. DISCUSSION The view from southwestern Angola offers a new perspective on the populating history of southern Africa and the Bantu expansions by showing that social stratification and different subsistence patterns are not always indicative of remnant groups, but may reflect Bantu-internal variation and ethnogenesis.
Collapse
Affiliation(s)
- Sandra Oliveira
- CIBIO/InBIO: Research Center in Biodiversity and Genetic Resources, Vairão 4485-661, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal
| | - Anne-Maria Fehn
- CIBIO/InBIO: Research Center in Biodiversity and Genetic Resources, Vairão 4485-661, Portugal.,Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, Jena 07745, Germany.,Institute for African Studies, Goethe University, Frankfurt 60323, Germany
| | - Teresa Aço
- Centro de Estudos do Deserto (CEDO), Namibe, Angola
| | - Fernanda Lages
- ISCED/Huíla-Instituto Superior de Ciências da Educação, Lubango, Angola
| | - Magdalena Gayà-Vidal
- CIBIO/InBIO: Research Center in Biodiversity and Genetic Resources, Vairão 4485-661, Portugal
| | - Brigitte Pakendorf
- Laboratoire Dynamique du Langage, UMR5596, CNRS & Université Lyon, Lyon 69007, France
| | - Mark Stoneking
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Jorge Rocha
- CIBIO/InBIO: Research Center in Biodiversity and Genetic Resources, Vairão 4485-661, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal.,ISCED/Huíla-Instituto Superior de Ciências da Educação, Lubango, Angola
| |
Collapse
|
27
|
Uren C, Möller M, van Helden PD, Henn BM, Hoal EG. Population structure and infectious disease risk in southern Africa. Mol Genet Genomics 2017; 292:499-509. [PMID: 28229227 DOI: 10.1007/s00438-017-1296-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 02/01/2017] [Indexed: 02/06/2023]
Abstract
The KhoeSan populations are the earliest known indigenous inhabitants of southern Africa. The relatively recent expansion of Bantu-speaking agropastoralists, as well as European colonial settlement along the south-west coast, dramatically changed patterns of genetic diversity in a region which had been largely isolated for thousands of years. Owing to this unique history, population structure in southern Africa reflects both the underlying KhoeSan genetic diversity as well as differential recent admixture. This population structure has a wide range of biomedical and sociocultural implications; such as changes in disease risk profiles. Here, we consolidate information from various population genetic studies that characterize admixture patterns in southern Africa with an aim to better understand differences in adverse disease phenotypes observed among groups. Our review confirms that ancestry has a direct impact on an individual's immune response to infectious diseases. In addition, we emphasize the importance of collaborative research, especially for populations in southern Africa that have a high incidence of potentially fatal infectious diseases such as HIV and tuberculosis.
Collapse
Affiliation(s)
- Caitlin Uren
- SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Tygerberg, Parow, 7500, South Africa
| | - Marlo Möller
- SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Tygerberg, Parow, 7500, South Africa
| | - Paul D van Helden
- SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Tygerberg, Parow, 7500, South Africa
| | - Brenna M Henn
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Eileen G Hoal
- SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Tygerberg, Parow, 7500, South Africa.
| |
Collapse
|
28
|
Fine-Scale Human Population Structure in Southern Africa Reflects Ecogeographic Boundaries. Genetics 2016; 204:303-14. [PMID: 27474727 DOI: 10.1534/genetics.116.187369] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 07/07/2016] [Indexed: 01/08/2023] Open
Abstract
Recent genetic studies have established that the KhoeSan populations of southern Africa are distinct from all other African populations and have remained largely isolated during human prehistory until ∼2000 years ago. Dozens of different KhoeSan groups exist, belonging to three different language families, but very little is known about their population history. We examine new genome-wide polymorphism data and whole mitochondrial genomes for >100 South Africans from the ≠Khomani San and Nama populations of the Northern Cape, analyzed in conjunction with 19 additional southern African populations. Our analyses reveal fine-scale population structure in and around the Kalahari Desert. Surprisingly, this structure does not always correspond to linguistic or subsistence categories as previously suggested, but rather reflects the role of geographic barriers and the ecology of the greater Kalahari Basin. Regardless of subsistence strategy, the indigenous Khoe-speaking Nama pastoralists and the N|u-speaking ≠Khomani (formerly hunter-gatherers) share ancestry with other Khoe-speaking forager populations that form a rim around the Kalahari Desert. We reconstruct earlier migration patterns and estimate that the southern Kalahari populations were among the last to experience gene flow from Bantu speakers, ∼14 generations ago. We conclude that local adoption of pastoralism, at least by the Nama, appears to have been primarily a cultural process with limited genetic impact from eastern Africa.
Collapse
|
29
|
Jacobson DR, Alexander AA, Tagoe C, Garvey WT, Williams SM, Tishkoff S, Modiano D, Sirima SB, Kalidi I, Toure A, Buxbaum JN. The prevalence and distribution of the amyloidogenic transthyretin (TTR) V122I allele in Africa. Mol Genet Genomic Med 2016; 4:548-56. [PMID: 27652282 PMCID: PMC5023940 DOI: 10.1002/mgg3.231] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 05/25/2016] [Accepted: 05/30/2016] [Indexed: 12/23/2022] Open
Abstract
Background Transthyretin (TTR) pV142I (rs76992529‐A) is one of the 113 variants in the human TTR gene associated with systemic amyloidosis. It results from a G to A transition at a CG dinucleotide in the codon for amino acid 122 of the mature protein (TTR V122I). The allele frequency is 0.0173 in African Americans. Methods PCR‐based assays to genotype 2767 DNA samples obtained from participants in genetic studies from various African populations supplemented with sequencing data from 529 samples within the 1000 Genomes Project. Results The rs76992529‐A variant allele was most prevalent (allele frequency 0.0253) in the contiguous West African countries of Sierra Leone, Guinea, Ivory Coast, Burkina Faso, Ghana, and Nigeria. In other African countries, the mean allele frequency was 0.011. Conclusions Our data are consistent with a small number of founder carriers of the amyloidogenic TTR V122I (p.Val142Ile) allele in southern West Africa, with no apparent advantage or disadvantage of an allele carrying newborn reaching adulthood. In U.S. African Americans, the allele represents a significant risk for congestive heart failure late in life. If clinical penetrance is similar in African countries with high allele frequencies, then cardiac amyloidosis could also represent a significant cause of heart disease in the elderly in those populations.
Collapse
Affiliation(s)
- Daniel R Jacobson
- Veterans Administration Boston Healthcare System and Department of Medicine Boston University School of Medicine Boston Massachusetts
| | - Alice A Alexander
- Research Service Veterans Administration Boston Healthcare System Boston Massachusetts
| | - Clement Tagoe
- Department of Medicine Albert Einstein College of Medicine Bronx New York
| | - W T Garvey
- Department of Nutrition Sciences University of Alabama School of Medicine Birmingham Alabama
| | - Scott M Williams
- Department of Genetics Geisel School of Medicine Dartmouth University Hanover New Hampshire
| | - Sara Tishkoff
- Departments of Genetics and Biology University of Pennsylvania Philadelphia Pennsylvania
| | - David Modiano
- Dipartimento di Sanità Pubblica e Malattie Infettive Sapienza Università di Roma Rome Italy
| | - Sodiomon B Sirima
- Centre National de Recherche et Formation sur le Paludisme, Ministère de la Santé Ouagadougou Burkina Faso
| | - Issa Kalidi
- Hematology Laboratory Hôpital Saint-Louis Paris France
| | - Amadou Toure
- Institut National de Recherche en Santé Publique Bamako Mali
| | - Joel N Buxbaum
- Department of Molecular and Experimental Medicine The Scripps Research Institute La Jolla California
| |
Collapse
|
30
|
Pinto JC, Oliveira S, Teixeira S, Martins D, Fehn AM, Aço T, Gayà-Vidal M, Rocha J. Food and pathogen adaptations in the Angolan Namib desert: Tracing the spread of lactase persistence and human African trypanosomiasis resistance into southwestern Africa. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 161:436-447. [PMID: 27402285 DOI: 10.1002/ajpa.23042] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 06/11/2016] [Accepted: 06/12/2016] [Indexed: 01/13/2023]
Abstract
OBJECTIVES We investigated the frequency distribution and haplotype diversity of human African trypanosomiasis (HAT) resistance and lactase persistence (LP) variants in populations from the Angolan Namib to trace the spread of these genetic adaptations into southwestern Africa. MATERIALS AND METHODS We resequenced two fragments of the LCT enhancer and the APOL1 gene and genotyped flanking short tandem repeat loci in six groups with different subsistence traditions living in the Angolan Namib, and in a comparative dataset including other populations from Africa and Europe. LP in the Angolan Namib is represented by the -14010*C allele, which is associated with a predominant haplotype that is shared with other southern and eastern African populations. While LP was found to be more frequent in foragers than in pastoralists, the frequencies of the two APOL1 variants associated with HAT-resistance (G1 and G2) did not differ between the two groups. The G1 allele is mostly associated with a single widespread haplotype. The G2 allele is linked to several haplotypes that are molecularly related to haplotypes found in other African Bantu-speaking populations. The putatively archaic G3 variant displayed more intra-allelic diversity in Africa than in Europe. DISCUSSION The LP adaptation was carried to southern Africa by non-Bantu speaking pastoralists from eastern Africa, but an obvious link between its presence in southern Angola and groups speaking languages of the Khoe-Kwadi family, as previously found in other areas, could not be confirmed. The presence of APOL1 variants G1 and G2 is linked to the Bantu expansions. Our results suggest that the G3 variant was retained in modern humans by incomplete lineage sorting.
Collapse
Affiliation(s)
- Joana C Pinto
- CIBIO/InBIO: Research Centre in Biodiversity and Genetic Resources, Vairão, 4485-661, Portugal
| | - Sandra Oliveira
- CIBIO/InBIO: Research Centre in Biodiversity and Genetic Resources, Vairão, 4485-661, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, 4169-007, Portugal
| | - Sérgio Teixeira
- CIBIO/InBIO: Research Centre in Biodiversity and Genetic Resources, Vairão, 4485-661, Portugal
| | - Dayana Martins
- ISCED/Huíla-Instituto Superior de Ciências da Educação, Lubango, Angola
| | - Anne-Maria Fehn
- CIBIO/InBIO: Research Centre in Biodiversity and Genetic Resources, Vairão, 4485-661, Portugal.,Max Planck Institute for the Science of Human History, Jena, 07745, Germany
| | - Teresa Aço
- Centro de Estudos do Deserto (CEDO), Namibe, Angola
| | - Magdalena Gayà-Vidal
- CIBIO/InBIO: Research Centre in Biodiversity and Genetic Resources, Vairão, 4485-661, Portugal
| | - Jorge Rocha
- CIBIO/InBIO: Research Centre in Biodiversity and Genetic Resources, Vairão, 4485-661, Portugal. .,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, 4169-007, Portugal.
| |
Collapse
|
31
|
Sadr K. Livestock First Reached Southern Africa in Two Separate Events. PLoS One 2015; 10:e0134215. [PMID: 26295347 PMCID: PMC4546641 DOI: 10.1371/journal.pone.0134215] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 07/06/2015] [Indexed: 11/18/2022] Open
Abstract
After several decades of research on the subject, we now know when the first livestock reached southern Africa but the question of how they got there remains a contentious topic. Debate centres on whether they were brought with a large migration of Khoe-speakers who originated from East Africa; or whether the livestock were traded down-the-line among hunter-gatherer communities; or indeed whether there was a long history of diverse small scale population movements in this part of the world, one or more of which 'infiltrated' livestock into southern Africa. A new analysis of the distribution of stone toolkits from a sizeable sample of sub-equatorial African Later Stone Age sites, coupled with existing knowledge of the distribution of the earliest livestock remains and ceramics vessels, has allowed us to isolate two separate infiltration events that brought the first livestock into southern Africa just over 2000 years ago; one infiltration was along the Atlantic seaboard and another entered the middle reaches of the Limpopo River Basin. These findings agree well with the latest results of genetic research which together indicate that multiple, small-scale infiltrations probably were responsible for bringing the first livestock into southern Africa.
Collapse
Affiliation(s)
- Karim Sadr
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa
- * E-mail:
| |
Collapse
|
32
|
Campbell MC, Hirbo JB, Townsend JP, Tishkoff SA. The peopling of the African continent and the diaspora into the new world. Curr Opin Genet Dev 2015; 29:120-32. [PMID: 25461616 DOI: 10.1016/j.gde.2014.09.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/03/2014] [Accepted: 09/05/2014] [Indexed: 12/22/2022]
Abstract
Africa is the birthplace of anatomically modern humans, and is the geographic origin of human migration across the globe within the last 100,000 years. The history of African populations has consisted of a number of demographic events that have influenced patterns of genetic and phenotypic variation across the continent. With the increasing amount of genomic data and corresponding developments in computational methods, researchers are able to explore long-standing evolutionary questions, expanding our understanding of human history within and outside of Africa. This review will summarize some of the recent findings regarding African demographic history, including the African Diaspora, and will briefly explore their implications for disease susceptibility in populations of African descent.
Collapse
|
33
|
Trombetta B, D'Atanasio E, Massaia A, Ippoliti M, Coppa A, Candilio F, Coia V, Russo G, Dugoujon JM, Moral P, Akar N, Sellitto D, Valesini G, Novelletto A, Scozzari R, Cruciani F. Phylogeographic Refinement and Large Scale Genotyping of Human Y Chromosome Haplogroup E Provide New Insights into the Dispersal of Early Pastoralists in the African Continent. Genome Biol Evol 2015; 7:1940-50. [PMID: 26108492 PMCID: PMC4524485 DOI: 10.1093/gbe/evv118] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Haplogroup E, defined by mutation M40, is the most common human Y chromosome clade within Africa. To increase the level of resolution of haplogroup E, we disclosed the phylogenetic relationships among 729 mutations found in 33 haplogroup DE Y-chromosomes sequenced at high coverage in previous studies. Additionally, we dissected the E-M35 subclade by genotyping 62 informative markers in 5,222 samples from 118 worldwide populations. The phylogeny of haplogroup E showed novel features compared with the previous topology, including a new basal dichotomy. Within haplogroup E-M35, we resolved all the previously known polytomies and assigned all the E-M35* chromosomes to five new different clades, all belonging to a newly identified subhaplogroup (E-V1515), which accounts for almost half of the E-M35 chromosomes from the Horn of Africa. Moreover, using a Bayesian phylogeographic analysis and a single nucleotide polymorphism-based approach we localized and dated the origin of this new lineage in the northern part of the Horn, about 12 ka. Time frames, phylogenetic structuring, and sociogeographic distribution of E-V1515 and its subclades are consistent with a multistep demic spread of pastoralism within north-eastern Africa and its subsequent diffusion to subequatorial areas. In addition, our results increase the discriminative power of the E-M35 haplogroup for use in forensic genetics through the identification of new ancestry-informative markers.
Collapse
Affiliation(s)
- Beniamino Trombetta
- Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma, Italy
| | - Eugenia D'Atanasio
- Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma, Italy
| | - Andrea Massaia
- Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma, Italy Present address: The Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
| | - Marco Ippoliti
- Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma, Italy
| | - Alfredo Coppa
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Italy
| | | | - Valentina Coia
- Accademia Europea di Bolzano (EURAC), Istituto per le Mummie e l'Iceman, Bolzano, Italy
| | - Gianluca Russo
- Dipartimento di Sanità Pubblica e Malattie Infettive, Sapienza Università di Roma, Italy
| | - Jean-Michel Dugoujon
- Laboratoire d'Anthropologie Moléculaire et Imagerie de Synthèse, UMR 5288, Centre National de la Recherche Scientifique (CNRS), Université Toulouse-3-Paul-Sabatier, Toulouse, France
| | - Pedro Moral
- Department of Animal Biology-Anthropology, Biodiversity Research Institute, University of Barcelona, Spain
| | - Nejat Akar
- Pediatrics Department, TOBB-Economy and Technology University Hospital, Ankara, Turkey
| | | | - Guido Valesini
- Dipartimento di Medicina Interna e Specialità Mediche, Sapienza Università di Roma, Italy
| | - Andrea Novelletto
- Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma, Italy
| | - Rosaria Scozzari
- Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma, Italy
| | - Fulvio Cruciani
- Dipartimento di Biologia e Biotecnologie "C. Darwin," Sapienza Università di Roma, Italy Istituto di Biologia e Patologia Molecolari, CNR, Rome Italy
| |
Collapse
|
34
|
Pugach I, Stoneking M. Genome-wide insights into the genetic history of human populations. INVESTIGATIVE GENETICS 2015; 6:6. [PMID: 25834724 PMCID: PMC4381409 DOI: 10.1186/s13323-015-0024-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 03/05/2015] [Indexed: 12/21/2022]
Abstract
Although mtDNA and the non-recombining Y chromosome (NRY) studies continue to provide valuable insights into the genetic history of human populations, recent technical, methodological and computational advances and the increasing availability of large-scale, genome-wide data from contemporary human populations around the world promise to reveal new aspects, resolve finer points, and provide a more detailed look at our past demographic history. Genome-wide data are particularly useful for inferring migrations, admixture, and fine structure, as well as for estimating population divergence and admixture times and fluctuations in effective population sizes. In this review, we highlight some of the stories that have emerged from the analyses of genome-wide SNP genotyping data concerning the human history of Southern Africa, India, Oceania, Island South East Asia, Europe and the Americas and comment on possible future study directions. We also discuss advantages and drawbacks of using SNP-arrays, with a particular focus on the ascertainment bias, and ways to circumvent it.
Collapse
Affiliation(s)
- Irina Pugach
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D04103 Leipzig, Germany
| | - Mark Stoneking
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D04103 Leipzig, Germany
| |
Collapse
|
35
|
Environments and trypanosomiasis risks for early herders in the later Holocene of the Lake Victoria basin, Kenya. Proc Natl Acad Sci U S A 2015; 112:3674-9. [PMID: 25775535 DOI: 10.1073/pnas.1423953112] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Specialized pastoralism developed ∼3 kya among Pastoral Neolithic Elmenteitan herders in eastern Africa. During this time, a mosaic of hunters and herders using diverse economic strategies flourished in southern Kenya. It has been argued that the risk for trypanosomiasis (sleeping sickness), carried by tsetse flies in bushy environments, had a significant influence on pastoral diversification and migration out of eastern Africa toward southern Africa ∼2 kya. Elmenteitan levels at Gogo Falls (ca. 1.9-1.6 kya) preserve a unique faunal record, including wild mammalian herbivores, domestic cattle and caprines, fish, and birds. It has been suggested that a bushy/woodland habitat that harbored tsetse fly constrained production of domestic herds and resulted in subsistence diversification. Stable isotope analysis of herbivore tooth enamel (n = 86) from this site reveals, instead, extensive C4 grazing by both domesticates and the majority of wild herbivores. Integrated with other ecological proxies (pollen and leaf wax biomarkers), these data imply an abundance of C4 grasses in the Lake Victoria basin at this time, and thus little risk for tsetse-related barriers to specialized pastoralism. These data provide empirical evidence for the existence of a grassy corridor through which small groups of herders could have passed to reach southern Africa.
Collapse
|
36
|
Jerardino A, Fort J, Isern N, Rondelli B. Cultural diffusion was the main driving mechanism of the Neolithic transition in southern Africa. PLoS One 2014; 9:e113672. [PMID: 25517968 PMCID: PMC4269434 DOI: 10.1371/journal.pone.0113672] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/27/2014] [Indexed: 11/19/2022] Open
Abstract
It is well known that the Neolithic transition spread across Europe at a speed of about 1 km/yr. This result has been previously interpreted as a range expansion of the Neolithic driven mainly by demic diffusion (whereas cultural diffusion played a secondary role). However, a long-standing problem is whether this value (1 km/yr) and its interpretation (mainly demic diffusion) are characteristic only of Europe or universal (i.e. intrinsic features of Neolithic transitions all over the world). So far Neolithic spread rates outside Europe have been barely measured, and Neolithic spread rates substantially faster than 1 km/yr have not been previously reported. Here we show that the transition from hunting and gathering into herding in southern Africa spread at a rate of about 2.4 km/yr, i.e. about twice faster than the European Neolithic transition. Thus the value 1 km/yr is not a universal feature of Neolithic transitions in the world. Resorting to a recent demic-cultural wave-of-advance model, we also find that the main mechanism at work in the southern African Neolithic spread was cultural diffusion (whereas demic diffusion played a secondary role). This is in sharp contrast to the European Neolithic. Our results further suggest that Neolithic spread rates could be mainly driven by cultural diffusion in cases where the final state of this transition is herding/pastoralism (such as in southern Africa) rather than farming and stockbreeding (as in Europe).
Collapse
Affiliation(s)
- Antonieta Jerardino
- ICREA/Department of Experimental & Health Sciences, Universitat Pompeu Fabra, CaSEs Research Group, Ramon Trias Fargas 25-27, 08005 Barcelona, Spain
- * E-mail:
| | - Joaquim Fort
- Complex Systems Lab, Department of Physics, University of Girona, C/. M Aurèlia Capmany 61, 17071 Girona, Catalonia, Spain
| | - Neus Isern
- Laboratori d'Arqueologia Quantitativa (LAQU), Departament de Prehistòria, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain
| | - Bernardo Rondelli
- CaSEs Research Group, Department of Archaeology and Anthropology, Institució Milà i Fontanals, Spanish National Research Council (IMF-CSIC), C/Egipcíaques, 15, 08001 Barcelona, Spain
| |
Collapse
|
37
|
Macholdt E, Slatkin M, Pakendorf B, Stoneking M. New insights into the history of the C-14010 lactase persistence variant in Eastern and Southern Africa. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 156:661-4. [PMID: 25448164 DOI: 10.1002/ajpa.22675] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/14/2014] [Accepted: 11/18/2014] [Indexed: 11/10/2022]
Abstract
Lactase persistence (LP), the ability to digest lactose into adulthood, is strongly associated with the cultural traits of pastoralism and milk-drinking among human populations, and several different genetic variants are known that confer LP. Recent studies of LP variants in Southern African populations, with a focus on Khoisan-speaking groups, found high frequencies of an LP variant (the C-14010 allele) that also occurs in Eastern Africa, and concluded that the C-14010 allele was brought to Southern Africa via a migration of pastoralists from Eastern Africa. However, this conclusion was based on indirect evidence; to date no study has jointly analyzed data on the C-14010 allele from both Southern African Khoisan-speaking groups and Eastern Africa. Here, we combine and analyze published data on the C-14010 allele in Southern and Eastern African populations, consisting of haplotypes with the C-14010 allele and four closely-linked short tandem repeat loci. Our results provide direct evidence for the previously-hypothesized Eastern African origin of the C-14010 allele in Southern African Khoisan-speaking groups. In addition, we find evidence for a separate introduction of the C-14010 allele into the Bantu-speaking Xhosa. The estimated selection intensity on the C-14010 allele in Eastern Africa is lower than that in Southern Africa, which suggests that in Eastern Africa the dietary changes conferring the fitness advantage associated with LP occurred some time after the origin of the C-14010 allele. Conversely, in Southern Africa the fitness advantage was present when the allele was introduced, as would be expected if pastoralism was introduced concomitantly.
Collapse
Affiliation(s)
- Enrico Macholdt
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, 04103, Leipzig, Germany
| | | | | | | |
Collapse
|
38
|
Ranciaro A, Campbell MC, Hirbo JB, Ko WY, Froment A, Anagnostou P, Kotze MJ, Ibrahim M, Nyambo T, Omar SA, Tishkoff SA. Genetic origins of lactase persistence and the spread of pastoralism in Africa. Am J Hum Genet 2014; 94:496-510. [PMID: 24630847 PMCID: PMC3980415 DOI: 10.1016/j.ajhg.2014.02.009] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Accepted: 02/14/2014] [Indexed: 10/25/2022] Open
Abstract
In humans, the ability to digest lactose, the sugar in milk, declines after weaning because of decreasing levels of the enzyme lactase-phlorizin hydrolase, encoded by LCT. However, some individuals maintain high enzyme amounts and are able to digest lactose into adulthood (i.e., they have the lactase-persistence [LP] trait). It is thought that selection has played a major role in maintaining this genetically determined phenotypic trait in different human populations that practice pastoralism. To identify variants associated with the LP trait and to study its evolutionary history in Africa, we sequenced MCM6 introns 9 and 13 and ~2 kb of the LCT promoter region in 819 individuals from 63 African populations and in 154 non-Africans from nine populations. We also genotyped four microsatellites in an ~198 kb region in a subset of 252 individuals to reconstruct the origin and spread of LP-associated variants in Africa. Additionally, we examined the association between LP and genetic variability at candidate regulatory regions in 513 individuals from eastern Africa. Our analyses confirmed the association between the LP trait and three common variants in intron 13 (C-14010, G-13907, and G-13915). Furthermore, we identified two additional LP-associated SNPs in intron 13 and the promoter region (G-12962 and T-956, respectively). Using neutrality tests based on the allele frequency spectrum and long-range linkage disequilibrium, we detected strong signatures of recent positive selection in eastern African populations and the Fulani from central Africa. In addition, haplotype analysis supported an eastern African origin of the C-14010 LP-associated mutation in southern Africa.
Collapse
Affiliation(s)
- Alessia Ranciaro
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Michael C Campbell
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jibril B Hirbo
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Wen-Ya Ko
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alain Froment
- UMR 208, Musée de l'Homme, Muséum National d'Histoire Naturelle and Institut de Recherche pour le Développement, 75116 Paris, France
| | - Paolo Anagnostou
- Dipartimento di Biologia Ambientale, Università La Sapienza, 00185 Rome, Italy; Istituto Italiano di Antropologia, 00100 Rome, Italy
| | - Maritha J Kotze
- Division of Anatomical Pathology, Department of Pathology, Faculty of Health Sciences, University of Stellenbosch, Tygerberg 7505, South Africa
| | - Muntaser Ibrahim
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, 15-13 Khartoum, Sudan
| | - Thomas Nyambo
- Department of Biochemistry, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Sabah A Omar
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, 54840-00200 Nairobi, Kenya
| | - Sarah A Tishkoff
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
39
|
Tracing pastoralist migrations to southern Africa with lactase persistence alleles. Curr Biol 2014; 24:875-9. [PMID: 24704073 DOI: 10.1016/j.cub.2014.03.027] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 02/17/2014] [Accepted: 03/11/2014] [Indexed: 01/31/2023]
Abstract
Although southern African Khoisan populations are often assumed to have remained largely isolated during prehistory, there is growing evidence for a migration of pastoralists from eastern Africa some 2,000 years ago, prior to the arrival of Bantu-speaking populations in southern Africa. Eastern Africa harbors distinctive lactase persistence (LP) alleles, and therefore LP alleles in southern African populations may be derived from this eastern African pastoralist migration. We sequenced the lactase enhancer region in 457 individuals from 18 Khoisan and seven Bantu-speaking groups from Botswana, Namibia, and Zambia and additionally genotyped four short tandem repeat (STR) loci that flank the lactase enhancer region. We found nine single-nucleotide polymorphisms, of which the most frequent is -14010(∗)C, which was previously found to be associated with LP in Kenya and Tanzania and to exhibit a strong signal of positive selection. This allele occurs in significantly higher frequency in pastoralist groups and in Khoe-speaking groups in our study, supporting the hypothesis of a migration of eastern African pastoralists that was primarily associated with Khoe speakers. Moreover, we find a signal of ongoing positive selection in all three pastoralist groups in our study, as well as (surprisingly) in two foraging groups.
Collapse
|
40
|
Breton G, Schlebusch C, Lombard M, Sjödin P, Soodyall H, Jakobsson M. Lactase Persistence Alleles Reveal Partial East African Ancestry of Southern African Khoe Pastoralists. Curr Biol 2014; 24:852-8. [DOI: 10.1016/j.cub.2014.02.041] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 12/20/2013] [Accepted: 02/15/2014] [Indexed: 01/18/2023]
|
41
|
Gebremeskel EI, Ibrahim ME. Y-chromosome E haplogroups: their distribution and implication to the origin of Afro-Asiatic languages and pastoralism. Eur J Hum Genet 2014; 22:1387-92. [PMID: 24667790 PMCID: PMC4231410 DOI: 10.1038/ejhg.2014.41] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 02/11/2014] [Accepted: 02/13/2014] [Indexed: 11/09/2022] Open
Abstract
Archeological and paleontological evidences point to East Africa as the likely area of early evolution of modern humans. Genetic studies also indicate that populations from the region often contain, but not exclusively, representatives of the more basal clades of mitochondrial and Y-chromosome phylogenies. Most Y-chromosome haplogroup diversity in Africa, however, is present within macrohaplogroup E that seem to have appeared 21 000-32 000 YBP somewhere between the Red Sea and Lake Chad. The combined analysis of 17 bi-allelic markers in 1214 Y chromosomes together with cultural background of 49 populations displayed in various metrics: network, multidimensional scaling, principal component analysis and neighbor-joining plots, indicate a major contribution of East African populations to the foundation of the macrohaplogroup, suggesting a diversification that predates the appearance of some cultural traits and the subsequent expansion that is more associated with the cultural and linguistic diversity witnessed today. The proto-Afro-Asiatic group carrying the E-P2 mutation may have appeared at this point in time and subsequently gave rise to the different major population groups including current speakers of the Afro-Asiatic languages and pastoralist populations.
Collapse
Affiliation(s)
- Eyoab I Gebremeskel
- 1] Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan [2] Department of Biology, Eritrea Institute of Technology, Mai-Nefhi, Eritrea
| | - Muntaser E Ibrahim
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| |
Collapse
|
42
|
Abstract
The history of southern Africa involved interactions between indigenous hunter-gatherers and a range of populations that moved into the region. Here we use genome-wide genetic data to show that there are at least two admixture events in the history of Khoisan populations (southern African hunter-gatherers and pastoralists who speak non-Bantu languages with click consonants). One involved populations related to Niger-Congo-speaking African populations, and the other introduced ancestry most closely related to west Eurasian (European or Middle Eastern) populations. We date this latter admixture event to ∼900-1,800 y ago and show that it had the largest demographic impact in Khoisan populations that speak Khoe-Kwadi languages. A similar signal of west Eurasian ancestry is present throughout eastern Africa. In particular, we also find evidence for two admixture events in the history of Kenyan, Tanzanian, and Ethiopian populations, the earlier of which involved populations related to west Eurasians and which we date to ∼2,700-3,300 y ago. We reconstruct the allele frequencies of the putative west Eurasian population in eastern Africa and show that this population is a good proxy for the west Eurasian ancestry in southern Africa. The most parsimonious explanation for these findings is that west Eurasian ancestry entered southern Africa indirectly through eastern Africa.
Collapse
|
43
|
Pierron D, Razafindrazaka H, Pagani L, Ricaut FX, Antao T, Capredon M, Sambo C, Radimilahy C, Rakotoarisoa JA, Blench RM, Letellier T, Kivisild T. Genome-wide evidence of Austronesian-Bantu admixture and cultural reversion in a hunter-gatherer group of Madagascar. Proc Natl Acad Sci U S A 2014; 111:936-41. [PMID: 24395773 PMCID: PMC3903192 DOI: 10.1073/pnas.1321860111] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Linguistic and cultural evidence suggest that Madagascar was the final point of two major dispersals of Austronesian- and Bantu-speaking populations. Today, the Mikea are described as the last-known Malagasy population reported to be still practicing a hunter-gatherer lifestyle. It is unclear, however, whether the Mikea descend from a remnant population that existed before the arrival of Austronesian and Bantu agriculturalists or whether it is only their lifestyle that separates them from the other contemporary populations of South Madagascar. To address these questions we have performed a genome-wide analysis of >700,000 SNP markers on 21 Mikea, 24 Vezo, and 24 Temoro individuals, together with 50 individuals from Bajo and Lebbo populations from Indonesia. Our analyses of these data in the context of data available from other Southeast Asian and African populations reveal that all three Malagasy populations are derived from the same admixture event involving Austronesian and Bantu sources. In contrast to the fact that most of the vocabulary of the Malagasy speakers is derived from the Barito group of the Austronesian language family, we observe that only one-third of their genetic ancestry is related to the populations of the Java-Kalimantan-Sulawesi area. Because no additional ancestry components distinctive for the Mikea were found, it is likely that they have adopted their hunter-gatherer way of life through cultural reversion, and selection signals suggest a genetic adaptation to their new lifestyle.
Collapse
Affiliation(s)
- Denis Pierron
- Laboratoire d'Anthropologie Moléculaire et Imagerie de Synthèse, Unité Mixte de Recherche 5288, Centre National de la Recherche Scientifique, Université de Toulouse, 31073 Toulouse, France
- Plateforme Technologique d'Innovation Biomédicale, Institut National de la Santé et de la Recherche Médicale, 33600 Pessac, France
| | - Harilanto Razafindrazaka
- Laboratoire d'Anthropologie Moléculaire et Imagerie de Synthèse, Unité Mixte de Recherche 5288, Centre National de la Recherche Scientifique, Université de Toulouse, 31073 Toulouse, France
- Plateforme Technologique d'Innovation Biomédicale, Institut National de la Santé et de la Recherche Médicale, 33600 Pessac, France
| | - Luca Pagani
- Division of Biological Anthropology, University of Cambridge, Cambridge CB2 3DZ, United Kingdom
| | - François-Xavier Ricaut
- Laboratoire d'Anthropologie Moléculaire et Imagerie de Synthèse, Unité Mixte de Recherche 5288, Centre National de la Recherche Scientifique, Université de Toulouse, 31073 Toulouse, France
| | - Tiago Antao
- Division of Biological Anthropology, University of Cambridge, Cambridge CB2 3DZ, United Kingdom
| | - Mélanie Capredon
- Laboratoire d'Anthropologie Moléculaire et Imagerie de Synthèse, Unité Mixte de Recherche 5288, Centre National de la Recherche Scientifique, Université de Toulouse, 31073 Toulouse, France
| | - Clément Sambo
- Ecole Normale Supérieure, Université de Toliara, Toliara 601, Madagascar
| | - Chantal Radimilahy
- Institut de Civilisations/Musée d'Art et d'Archéologie, Isoraka, Antananarivo 101, Madagascar; and
| | - Jean-Aimé Rakotoarisoa
- Institut de Civilisations/Musée d'Art et d'Archéologie, Isoraka, Antananarivo 101, Madagascar; and
| | - Roger M. Blench
- Kay Williamson Educational Foundation, Cambridge CB1 2AL, United Kingdom
| | - Thierry Letellier
- Laboratoire d'Anthropologie Moléculaire et Imagerie de Synthèse, Unité Mixte de Recherche 5288, Centre National de la Recherche Scientifique, Université de Toulouse, 31073 Toulouse, France
- Plateforme Technologique d'Innovation Biomédicale, Institut National de la Santé et de la Recherche Médicale, 33600 Pessac, France
| | - Toomas Kivisild
- Division of Biological Anthropology, University of Cambridge, Cambridge CB2 3DZ, United Kingdom
| |
Collapse
|
44
|
Affiliation(s)
- Tom Güldemann
- Humboldt University Berlin / Max Planck Institute for Evolutionary Anthropology Leipzig
| |
Collapse
|
45
|
Barbieri C, Güldemann T, Naumann C, Gerlach L, Berthold F, Nakagawa H, Mpoloka SW, Stoneking M, Pakendorf B. Unraveling the complex maternal history of Southern African Khoisan populations. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2013; 153:435-48. [PMID: 24323467 DOI: 10.1002/ajpa.22441] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 11/12/2013] [Accepted: 11/15/2013] [Indexed: 02/03/2023]
Abstract
The Khoisan populations of southern Africa are known to harbor some of the deepest-rooting lineages of human mtDNA; however, their relationships are as yet poorly understood. Here, we report the results of analyses of complete mtDNA genome sequences from nearly 700 individuals representing 26 populations of southern Africa who speak diverse Khoisan and Bantu languages. Our data reveal a multilayered history of the indigenous populations of southern Africa, who are likely to be the result of admixture of different genetic substrates, such as resident forager populations and pre-Bantu pastoralists from East Africa. We find high levels of genetic differentiation of the Khoisan populations, which can be explained by the effect of drift together with a partial uxorilocal/multilocal residence pattern. Furthermore, there is evidence of extensive contact, not only between geographically proximate groups, but also across wider areas. The results of this contact, which may have played a role in the diffusion of common cultural and linguistic features, are especially evident in the Khoisan populations of the central Kalahari.
Collapse
Affiliation(s)
- Chiara Barbieri
- Max Planck Research Group on Comparative Population Linguistics, MPI for Evolutionary Anthropology, Leipzig, 04103, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Rito T, Richards MB, Fernandes V, Alshamali F, Cerny V, Pereira L, Soares P. The first modern human dispersals across Africa. PLoS One 2013; 8:e80031. [PMID: 24236171 PMCID: PMC3827445 DOI: 10.1371/journal.pone.0080031] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 09/26/2013] [Indexed: 12/11/2022] Open
Abstract
The emergence of more refined chronologies for climate change and archaeology in prehistoric Africa, and for the evolution of human mitochondrial DNA (mtDNA), now make it feasible to test more sophisticated models of early modern human dispersals suggested by mtDNA distributions. Here we have generated 42 novel whole-mtDNA genomes belonging to haplogroup L0, the most divergent clade in the maternal line of descent, and analysed them alongside the growing database of African lineages belonging to L0's sister clade, L1'6. We propose that the last common ancestor of modern human mtDNAs (carried by "mitochondrial Eve") possibly arose in central Africa ~180 ka, at a time of low population size. By ~130 ka two distinct groups of anatomically modern humans co-existed in Africa: broadly, the ancestors of many modern-day Khoe and San populations in the south and a second central/eastern African group that includes the ancestors of most extant worldwide populations. Early modern human dispersals correlate with climate changes, particularly the tropical African "megadroughts" of MIS 5 (marine isotope stage 5, 135-75 ka) which paradoxically may have facilitated expansions in central and eastern Africa, ultimately triggering the dispersal out of Africa of people carrying haplogroup L3 ~60 ka. Two south to east migrations are discernible within haplogroup LO. One, between 120 and 75 ka, represents the first unambiguous long-range modern human dispersal detected by mtDNA and might have allowed the dispersal of several markers of modernity. A second one, within the last 20 ka signalled by L0d, may have been responsible for the spread of southern click-consonant languages to eastern Africa, contrary to the view that these eastern examples constitute relicts of an ancient, much wider distribution.
Collapse
Affiliation(s)
- Teresa Rito
- IPATIMUP (Instituto de Patologia e Imunologia Molecular da Universidade do Porto), Porto, Portugal
| | - Martin B. Richards
- School of Applied Sciences, University of Huddersfield, QueensGate, Huddersfield, United Kingdom
| | - Verónica Fernandes
- IPATIMUP (Instituto de Patologia e Imunologia Molecular da Universidade do Porto), Porto, Portugal
- Institute of Integrative and Comparative Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Farida Alshamali
- Dubai Police GHQ - General Department of Forensic Sciences & Criminology, Dubai, United Arab Emirates
| | - Viktor Cerny
- Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic
- Institute for Advanced Study, Paris, France
| | - Luísa Pereira
- IPATIMUP (Instituto de Patologia e Imunologia Molecular da Universidade do Porto), Porto, Portugal
- Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Pedro Soares
- IPATIMUP (Instituto de Patologia e Imunologia Molecular da Universidade do Porto), Porto, Portugal
- * E-mail:
| |
Collapse
|
47
|
Bučková J, Černý V, Novelletto A. Multiple and differentiated contributions to the male gene pool of pastoral and farmer populations of the African Sahel. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2013; 151:10-21. [DOI: 10.1002/ajpa.22236] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 01/09/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Jana Bučková
- Department of Anthropology and Human Genetics, Faculty of Science; Charles University; Prague; Czech Republic
| | | | | |
Collapse
|
48
|
Sacks BN, Brown SK, Stephens D, Pedersen NC, Wu JT, Berry O. Y Chromosome Analysis of Dingoes and Southeast Asian Village Dogs Suggests a Neolithic Continental Expansion from Southeast Asia Followed by Multiple Austronesian Dispersals. Mol Biol Evol 2013; 30:1103-18. [DOI: 10.1093/molbev/mst027] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
49
|
Boattini A, Castrì L, Sarno S, Useli A, Cioffi M, Sazzini M, Garagnani P, De Fanti S, Pettener D, Luiselli D. mtDNA variation in East Africa unravels the history of Afro-Asiatic groups. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2013; 150:375-85. [PMID: 23283748 DOI: 10.1002/ajpa.22212] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 11/19/2012] [Indexed: 01/01/2023]
Abstract
East Africa (EA) has witnessed pivotal steps in the history of human evolution. Due to its high environmental and cultural variability, and to the long-term human presence there, the genetic structure of modern EA populations is one of the most complicated puzzles in human diversity worldwide. Similarly, the widespread Afro-Asiatic (AA) linguistic phylum reaches its highest levels of internal differentiation in EA. To disentangle this complex ethno-linguistic pattern, we studied mtDNA variability in 1,671 individuals (452 of which were newly typed) from 30 EA populations and compared our data with those from 40 populations (2970 individuals) from Central and Northern Africa and the Levant, affiliated to the AA phylum. The genetic structure of the studied populations--explored using spatial Principal Component Analysis and Model-based clustering--turned out to be composed of four clusters, each with different geographic distribution and/or linguistic affiliation, and signaling different population events in the history of the region. One cluster is widespread in Ethiopia, where it is associated with different AA-speaking populations, and shows shared ancestry with Semitic-speaking groups from Yemen and Egypt and AA-Chadic-speaking groups from Central Africa. Two clusters included populations from Southern Ethiopia, Kenya and Tanzania. Despite high and recent gene-flow (Bantu, Nilo-Saharan pastoralists), one of them is associated with a more ancient AA-Cushitic stratum. Most North-African and Levantine populations (AA-Berber, AA-Semitic) were grouped in a fourth and more differentiated cluster. We therefore conclude that EA genetic variability, although heavily influenced by migration processes, conserves traces of more ancient strata.
Collapse
Affiliation(s)
- Alessio Boattini
- Department of Biological, Geological and Environmental Sciences, Laboratory of Molecular Anthropology, University of Bologna, 40126, Bologna, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Schlebusch CM, Soodyall H. Extensive Population Structure in San, Khoe, and Mixed Ancestry Populations from Southern Africa Revealed by 44 Short 5-SNP Haplotypes. Hum Biol 2012; 84:695-724. [DOI: 10.3378/027.084.0603] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2013] [Indexed: 11/05/2022]
|