Nature | www.nature.com | 1 Article Human origins in a southern African palaeo-wetland and first migrations Eva K. F. Chan1,2, Axel Timmermann3,4*, Benedetta F. Baldi1, Andy E. Moore5, Ruth J. Lyons1, Sun-Seon Lee3,4, Anton M. F. Kalsbeek1, Desiree C. Petersen1,11, Hannes Rautenbach6,7,12, Hagen E. A. Förtsch8, M. S. Riana Bornman7 & Vanessa M. Hayes1,2,7,9,10* Anatomically modern humans originated in Africa around 200 thousand years ago (ka)1–4. Although some of the oldest skeletal remains suggest an eastern African origin2, southern Africa is home to contemporary populations that represent the earliest branch of human genetic phylogeny5,6. Here we generate, to our knowledge, the largest resource for the poorly represented and deepest-rooting maternal L0 mitochondrial DNA branch (198 new mitogenomes for a total of 1,217 mitogenomes) from contemporary southern Africans and show the geographical isolation of L0d1’2, L0k and L0g KhoeSan descendants south of the Zambezi river in Africa. By establishing mitogenomic timelines, frequencies and dispersals, we show that the L0 lineage emerged within the residual Makgadikgadi–Okavango palaeo-wetland of southern Africa7, approximately 200 ka (95% confidence interval, 240–165 ka). Genetic divergence points to a sustained 70,000-year-long existence of the L0 lineage before an out-of-homeland northeast–southwest dispersal between 130 and 110 ka. Palaeo- climate proxy and model data suggest that increased humidity opened green corridors, first to the northeast then to the southwest. Subsequent drying of the homeland corresponds to a sustained effective population size (L0k), whereas wet–dry cycles and probable adaptation to marine foraging allowed the southwestern migrants to achieve population growth (L0d1’2), as supported by extensive south-coastal archaeological evidence8–10. Taken together, we propose a southern African origin of anatomically modern humans with sustained homeland occupation before the first migrations of people that appear to have been driven by regional climate changes. Southern Africa has long been considered to be one of the regions in which anatomically modern humans (AMHs) originated. Home to con- temporary populations who represent the earliest human lineages, evo- lutionary time estimates have largely been based on mitochondrial DNA (mitogenomes)1,6. The maternal human phylogenetic tree consists of two major branches, the extensive L1’6—which includes the out-of-Africa ancestral L3 sub-branch (or haplogroup)—and the rare deep-rooting L0. The L0 lineage is predominated by southern African haplogroups: L0d, L0k and the recently described L0g6. By contrast, the rare L0f and common L0a lineages are dispersed throughout sub-Saharan Africa1,3,6. Through L0 pre-screening, we identified 198 southern Africans with poorly represented haplogroups for whom the mitogenome was sequenced (Supplementary Table 1), allowing for a combined analysis of 1,217 mitogenomes (Fig. 1a and Extended Data Table 1). We ethno-linguistically classified study participants as KhoeSan— southern African populations who traditionally practiced foraging and spoke languages containing ‘click’ consonants—or non-KhoeSan individuals. Non-KhoeSan who have KhoeSan-derived L0 mitogenomes are referred to in this study as KhoeSan ancestral, with further geo- graphical classification (Fig. 1b and Extended Data Table 2; terminol- ogy pertaining to southern African KhoeSan populations is complex and contentious, see Methods for further discussion). Contemporary KhoeSan include Kalahari KhoeSan (Kx’a, Tuu and central Khoe–Kwadi speakers) and west-coastal KhoeSan (Khoe–Kwadi Nama speakers)11. Peoples who speak Southern Bantu languages, who migrated down the east coast of Africa around 1,500 years ago, may have acquired an east-coastal KhoeSan heritage12. The arrival of European colonists to the Cape in mid-1600s gave rise to the South African Coloured and Namibian Baster populations (of Eurasian and indigenous descent), who acquired a Cape KhoeSan heritage13. Excluding the east African Sandawe and Hadza (whose languages also contain click consonants), indigenous KhoeSan populations appear to be absent northeast of the Zambezi river, supported by the lack of skeletal remains representing the KhoeSan-like hunter–forager morphology14. We classified the 198 new https://doi.org/10.1038/s41586-019-1714-1 Received: 30 October 2018 Accepted: 24 September 2019 Published online: Ńʼn =«ìت³ã ŃŁłŊ 1Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia. 2St Vincent’s Clinical School, University of New South Wales, Sydney, New South Wales, Australia. 3Center for Climate Physics, Institute for Basic Science, Busan, South Korea. 4Pusan National University, Busan, South Korea. 5Department of Geology, Rhodes University, Grahamstown, South Africa. 6Climate Change and Variability, South African Weather Service, Pretoria, South Africa. 7School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa. 8Windhoek Central Hospital, Windhoek, Namibia. 9Faculty of Health Sciences, University of Limpopo, Sovenga, South Africa. 10Central Clinical School, University of Sydney, Sydney, New South Wales, Australia. 11Present address: The Centre for Proteomic and Genomic Research, Cape Town, South Africa. 12Present address: Akademia, Johannesburg, South Africa. *e-mail: timmermann@pusan.ac.kr; v.hayes@garvan.org.au 2 | Nature | www.nature.com Article mitogenomes as Kalahari (n = 18), west-coastal (n = 21), Cape (n = 109) and east-coastal (n = 29) KhoeSan, or non-KhoeSan (Bantu, n = 19), although two mitogenomes were classed as unknown. Using these identifiers, we provide a best-fit classification for all 1,217 L0 mitogenomes (Sup- plementary Table 2). Phylogenetic analysis confirms the major L0 haplogroups, with the exclusion of L0b (Extended Data Fig. 1). Using a subset of 461 mitog- enomes, including all of the rare lineages, we establish the coalescence times within the L0 lineage (Fig. 2a and Supplementary Table 3) and use the complete dataset to reconstruct geographical dispersals (Fig. 2b). We redefine the emergence of the L0 lineage to 50–25 thousand years (kyr) before previous estimates1,6, around 200 ka (95% confidence interval, 240–165 ka). L0d’k (n = 309; coalesced around 187 ka (the number of mitogenomes and the coalescence time are provided for each lineage)) is largely KhoeSan-specific, emerging approximately 20 kyr before the widely dispersed L0a’b’f’g sister branch (n = 152; around 164 ka). Although the exact branch resolution for L0k remains undetermined, we observe a preference for L0d’k (posterior probability of approximately 0.6) over L0a’b’f’g’k (posterior probability of about 0.4). Irrespective of this, the L0k (n = 113) lineage appears to remain stable for around 130 kyr before diverging into the Kalahari-specific L0k1 lineage, which is predominated by L0k1a (85 out of 94), and rarer L0k1b and L0k2 line- ages distributed around the Zambezi river (Extended Data Fig. 2a). The L0d lineage remains stable for almost 60 kyr before splitting into the KhoeSan-specific L0d1’2 and rarer L0d3 lineages. Coalescing around 113 ka, L0d2 (n = 226) emerges approximately 15 kyr before L0d1 (n = 452). Within L0d2 (emerging about 91 ka), L0d2c diverged the earliest (n = 53; around 84 ka) with a broad and almost even KhoeSan-regional distribution (Extended Data Fig. 3 and Supplementary Table 4). In 2014, we derived an ancient L0d2c1c mitogenome from a sample of the skeleton of an approximately 2,330-year-old Cape-coastal marine forager (St Helena (StHe)/UCT606)15. Predating archaeologi- cal evidence for sheep herding in the region12,16, we proposed that this L0d2c sub-clade represented a pre-pastoral indigenous southern Afri- can lineage. Recently, whole-genome sequencing confirmed a unique southern African heritage, whereas two younger (less than 2 kyr old) Cape skeletons showed a genetic link to eastern Africa and the associ- ated pastoralist migration17. Previously, an overrepresentation of the L0d2b (28 out of 44; around 65 ka) and L0d2a (62 out of 118; around 60 ka) lineages within the Kalahari KhoeSan has been observed; how- ever, by doubling the contribution of the L0d2d (6 out of 11) lineage, we show a broad southern African distribution (Extended Data Fig. 3 and Supplementary Tables 5, 6). While L0d1 is also spread throughout the KhoeSan-regional identifier, we show notable overrepresentation of the L0d1b (104 out of 174; about 69 ka) and L0d1c (151 out of 184; approximately 59 ka) lineages within the Kalahari and of the L0d1a (32 out of 91; around 44 ka) lineage within the Cape (Extended Data Fig. 4). We contribute two new KhoeSan-ancestral L0d1d mitogenomes to the single published mitogenome6. In contrast to L01’2, the L0d3 lineage is not specific to southern Africa. Although L0d3b (around 30 ka) appears to be KhoeSan-specific, the rarer L0d3a (about 42 ka) lineage is exclusively found north of the Zambezi river. Notably, three out of six L0d3a mitogenomes were derived from east African Sandawe individuals. Our data support previous studies that have suggested a genetic link between east Africa and the earliest southern Africans17, who last shared a common ancestor around 59 ka. By adding a large number of mitogenomes (27 out of 40) to the L0d3 lineage, we observe overrepresentation of L0d3b in the Cape KhoeSan identifier (21 out of 34) (Extended Data Fig. 2b and Supplementary Table 7). Using a previously reported identifier that distinguishes mater- nal KhoeSan ancestry for the Coloured and Baster populations13, we show that the L0d3b lineage is specific to the Coloured population, whereas the new L0d2b1a2a sub-clade is specific to the Baster popula- tion (Extended Data Fig. 3b). Within the L0a’b’f’g lineage, L0f is highly divergent (emerging around 125 ka; 95% confidence interval,149–101 ka). By including a further five L0f mitogenomes, we were able to show that L0f1 (13 out of 27; around 113 ka) predominates south and L0f2’3 (14 out of 27; about 121 ka) north of the Zambezi river (Extended Data Fig. 2c and Supplementary Table 8). Within L0f1, we recognize three new branches: the northeast sister clades L0f1c (Zambian) and L0f1b (Tanzanian), and the   South African clade L0f1a (n = 8). Lack of L0f representation within contemporary KhoeSan suggests that the presence of L0f1a within South Africa is probably a result of more recent east-coastal agropastoral back-migration. While the L0a’g lineages coalesce around 117 ka (95% confidence inter- val, 145–94 ka), contributing 19 southern African to 347 L0a mitoge- nomes, we concur that the L0a lineage probably diverged northeast of the Zambezi river (around 85 ka) and spread throughout Africa3; the a b Published: 1,019 This study: 198 Total: 1,217 Archaeological caves 11 4 1 4 8 6 6 5 1 8 1 9 3 1 19 124 63 211 322 2 18 77 114 121 DRC Tanzania Zambia Zambezi river Zimbabwe Mozam- bique South Africa Botswana Namibia Angola East-coastal KhoeSan Kalahari KhoeSan Lower Zambezi Middle Zambezi Upper Zambezi Makgadikgadi pan Limpopo Okavango Kafue Okavango delta Non-KhoeSan Cape KhoeSan West-coastal KhoeSan St Helena skeleton Fig. 1 | Geographical distribution of 1,217 L0 mitogenomes. a, Countries within (n = 1,139) or outside (n = 78) Africa from which L0 mitogenomes were sourced, including 198 new L0 mitogenomes (black numbers on the map). DRC, Democratic Republic of the Congo. b, Present-day southern Africa showing the geographical distribution of KhoeSan population identifiers defined as KhoeSan (orange), Kalahari and west-coastal; KhoeSan ancestral (green), Cape or east-coastal. The Zambezi river provides a geographical division between the KhoeSan and mostly non-KhoeSan population identifiers. Maps were generated in the R package ‘maps’ v.3.3.037. Nature | www.nature.com | 3 southern representation of the L0a1b and L0a2a lineages are probably a result of a Bantu back-migration (Extended Data Fig. 5). First described in a Kx’a-speaking hunter-gatherer6, we now contribute three additional and reclassify five published mitogenomes as L0g (Extended Data Fig. 2d and Supplementary Table 9). As the L0g lineage has a broad KhoeSan and KhoeSan-ancestral distribution, we hypothesize that this lineage diverged southwest of the Zambezi river (around 69 ka), similar to the L0d1’2 lineage. Our results suggest that the greater Zambezi river basin, particu- larly the Kalahari region, had a critical role in shaping the emergence and prehistory of AMHs. Now a semi-desert, this region consists of salt pans within northern Botswana that represent desiccated vestiges of palaeo-lake Makgadikgadi, which at its peak in the early Pleistocene would have been the largest lake in Africa7,18. Contraction of the Mak- gadikgadi palaeo-lake during the Middle Pleistocene was accompanied by development of the Okavango delta as a result of neotectonic rift- ing, which—together with smaller lakes from the upper Zambezi to the Kafue rivers—would have created a vast residual wetland favourable for habitation by humans and mammals more broadly19 (Fig. 2c). Today, the harsh Kalahari climate and oxygen-rich salt pans are not ideal for fossil and pollen preservation, respectively. However, period-relevant lithic artefacts are documented from the Makgadikgadi pans and sur- roundings7,20,21, while palynology suggests that this region was once a grassland and forest biome22. Our data further suggest that the Mak- gadikgadi–Okavango palaeo-wetland sustained the existence of AMHs for around 70 kyr, supported by mitochondrial data of ancestral giraffe, lion and zebra23–25, before out-of-homeland migrations split the founder homeland populations of the L0d, L0f and L0a’g lineages. Southwest of their homeland, the L0d1’2 lineage experienced episodic splits and showed a broad south-coastal occupation of the emerged sub-populations, whereas the ancestors of the L0g lineage were less successful. Bayesian skyline plot (BSP) (Fig. 2c) analysis confirms effective population growth for the L0d1’2 lineage (BSP L0d1’2), whereas extensive archaeological evidence indicates cognitively modern human behaviour at the southern tip of Africa8–10 between approximately 100 and 60 ka, together with an associated increase in the density of time- appropriate archaeological sites in coastal compared to inland regions26. Northeast of their homeland, the L0d3 and L0f lineages are less success- ful, whereas the L0a lineage underwent considerable diversification, which post-dates the out-of-Africa migration (BSP L0a; Fig. 2c). The northeast migration route is further supported by the appearance of data-appropriate archaeological sites26. Within their homeland, the population carrying the L0k lineage sustained a constant effective popu- lation size (BSP L0k), as did the Kalahari-predominant L0d2b, L0d2a and L0d1c lineages. Although the presence of L0k in Zambia has been sug- gested to represent contact with an ancient pre-Bantu population27, we propose that these rare lineages represent an ancient out-of-homeland branch of the ancestral KhoeSan population. Orbitally driven large-scale hydroclimate variations have been pro- posed as a contributor of early human migrations28,29. In some studies, wetter conditions and resulting ‘green corridors’ have been proposed to explain the out-of-Africa migration (a ‘pull’ scenario), whereas others have proposed that drier conditions and resulting food shortages forced dispersals (a ‘push’ scenario)30. To determine whether our predicted homeland isolation and major dispersals may have been driven by cli- mate shifts, we analysed four key palaeo-hydroclimate datasets29,31–33, along with a transient 784-kyr-long glacial–interglacial simulation con- ducted with the LOVECLIM Earth system model28 (Fig. 3). Although limited by available palaeo-proxy records and a climate model of inter- mediate complexity, we observe a considerable degree of coherence on orbital timescales (Extended Data Fig. 6). During the homeland period (200–130 ka), palaeo-data link the 21-kyr-long precession cycle, which St. Helena skeleton Archaeological caves Makgadikgadi– Okavango wetlandsL0k L0g L0a L0d3 L0f L0d1’2 L0 Southwest migration Northeast migration c 100 1,000 10,000 100,000 L0a 70 40 10 0 Date (ka) 100 1,000 10,000 100,000 L0d1’2 70 40 10 0 100 1,000 10,000 100,000 L0k 70 40 10 0 Date (ka) Date (ka) EP S EP S EP S L0f1a (n = 8) L0f1b (n = 2) L0f1c (n = 3) L0f1 L0d3b (n = 34) L0d3a (n = 6) 21 5 2 6 L0d3 657 19 1 L0d1’2 L0k1a (n = 94) L0k2 (n = 11) 8 2 85 9 1 L0k b 0 100,000 50,000 200,000 150,000 250,000 Ye ar s be fo re p re se nt L0fL0d2b L0g Som20 L0d2cL0d1c L0b L0d2a L0k1a2 L0aL0d1b L0k1a1 L0d3b L0d2dL0d1d L0k1bL0d1a L0d3a L0k2 0.9997 0.4746 0.9986 0.9746 0.2403 0.9283 0.9997 0.9973 0.6008 0.9998 0.9971 0.991 a Fig. 2 | L0 phylogenetic tree, geographical distributions of the major southern African L0 haplogroup and out-of-homeland L0 dispersal routes. a, Phylogenetic branching and coalescence times derived from a focused subset of 461 L0 mitogenomes, including all rare branches, and anchored to Neanderthals (Homo neanderthalensis; n = 7). The Somalian-derived (Som20) L0d3 mitogenome3 could not be assigned. b, Geographical distribution (identifiers described in Fig. 1b) for all KhoeSan-specific mitogenomes (out of 1,217): L0d3 (n = 40), L0d1’2 (n = 677, excluding one unknown), L0k (n = 105, excluding seven L0k1b and a single Yemen-derived L0k2), and L0f1 (n = 13). Predominant geographical representation (shaded regions), with region- specific overflow represented by the total number of mitogenomes, including the country-specific representation north of the Zambezi river. c, Schematic map of southern Africa representing the Makgadikgadi–Okavango palaeo- wetland sustained AMH homeland (200–130 ka), supported by archaeological data (represented by the trowel symbol)7 and genetic wildlife data (represented by the lion, zebra and giraffe symbols)23–25. The out-of-homeland migration (130–110 ka), results in the split of L0d with L0a’g and L0f divergence. L0d3, L0a and L0f migrate in a northeast direction, L0d1’2 and L0g migrate southwest, while L0k remains in the homeland. Insets show BSP analyses of effective population sizes (EPS) of major L0 haplogroups over time, predicting the maintenance of the homeland L0k population (orange), population growth for the broadly dispersed southwest L0d1’2 migrants (purple), which is supported by archaeological evidence (100–60 ka)8–10 and the StHe mitogenome15, while population growth of the northeast L0a migrants coincides with the out-of- Africa migration (aqua). Maps were generated in the R package maps v.3.3.037. 4 | Nature | www.nature.com Article arises from a combination of Earth’s axis wobble and a slow rotation of Earth’s entire orbit around the Sun (Fig. 3a), with three wet–dry cycles (Fig. 3b). By contrast, the climate model simulates an extended drought, owing to a more pronounced eccentricity signal (Fig. 3e), suggestive of a wetland oasis in an otherwise vast harsh environment. During the out-of-homeland period (130–110 ka), our model simula- tion supports humid conditions to the northeast that facilitated the first dispersals, concurring with L0f coalescence (around 125 ka) (Fig. 3d). By contrast, the region southwest of the homeland experienced an approximately 15-kyr-long megadrought before an orbital shift created the favourable humid conditions that led to the dispersal of the L0d1’2 lineage (around 113 ka) (Fig. 3f), which is also supported by palaeo-data (Fig. 3c). This is also around the time the northeast L0a and southwest L0g migrants last share a common ancestor (around 117 ka). During the last glacial period (approximately 100–11 ka), we observe a reduction in the amplitude of the changes in orbital-scale hydroclimate and overall drying within the homeland (Fig. 3b), whereas the southwest coastal hydroclimate was dominated by precessional variability and showed relatively agreeable environmental conditions (Fig. 3c, f). Notably, peri- ods of deceleration and acceleration in the estimates of the effective population size of the L0d1’2 lineage coincide with regional changes in hydroclimate, further linking climate, population size and evolution. We propose that the Makgadikgadi–Okavango palaeo-wetland was the possible homeland of AMHs. Although one cannot exclude the possibility of a polycentric origin34, this deltaic–lacustrine ecosystem would have provided an ideal geographical locality for the evolution and 70-kyr-long sustained existence of the deepest-branching maternal founder population of AMHs. Increased humid conditions, supported by palaeo-lake system reconstructions35, between 130 and 110 ka would have opened green corridors for successful northeast–southwest migrations, supporting a pull scenario. Drying within the homeland following the out-of-homeland period, supported by hydroclimate data (110–100 ka) and a model simulation (100–80 ka), would have created a push scenario, in which a reduced carrying capacity of the land would have increased pressure to seek out climatically more favourable regions. We propose that the southwest migrants maintained a successful coastal forager existence, while the northeast migrants—similar to the later-branching population of L1’6—gave rise to ancestral pastoral and farming popula- tions. A recent publication36 provides further mitochondrial evidence to support the northeast out-of-homeland migration route and expan- sion into eastern Africa around 70–60 ka. Revealing a southern African homeland for the emergence and extended subsistence of the L0 lineage, we propose that an out-of-homeland migration event, which was prob- ably driven by astronomically induced regional shifts in hydroclimate, shaped the present-day ethnic and genetic diversity of modern humans. Online content Any methods, additional references, Nature Research reporting summa- ries, source data, extended data, supplementary information, acknowl- edgements, peer review information; details of author contributions and competing interests; and statements of data and code availability are available at https://doi.org/10.1038/s41586-019-1714-1. 1. Behar, D. M. et al. The dawn of human matrilineal diversity. Am. J. Hum. Genet. 82, 1130–1140 (2008). time [ka] 050100150200250Au st ra l s um m er in so la tio n (W p er m 2 ) 400 420 440 460 480 500 520 540 time [ka] 050100150200250 –2 –1 0 1 2 3 P op ul at io n si ze (L 0k ) 101 102 103 104 Date (ka) 050100150200250 H yd ro cl im at e (w es t) –3 –2 –1 0 1 2 3 P op ul at io n si ze (L 0d 1’ 2) 102 103 104 time [ka] 050100150200250 LO VE C LI M p re ci pi ta tio n (N E) -3 –2 –1 0 1 2 3 time [ka] 050150200250L O VE C LI M p re ci pi ta tio n (h om el an d) –2 –1 0 1 2 3 Date (ka) 050100150200250L O VE C LI M p re ci pi ta tio n (S W ) –3 –2 –1 0 1 2 3 W et D ry L0d1’2 L0k L0f Obliquity Precession Eccentricity Homeland Northeast migration Southwest migration W et D ry L0, L0d’k, L0a’b’f’g Precession H yd ro cl im at e (c en tra l a nd e as t) a d b e c f Makgadikgadi highstands Fig. 3 | Reconstructed and simulated climatic conditions during the out- of-homeland migration. a, Austral summer insolation changes (blue) at 27° S. b, A hydroclimate composite of eastern and central southern Africa (shading) was obtained by averaging the Fe/K runoff record from core CD154-1006P31 and the Pretoria Salt Pan rainfall reconstruction29, extended from 250 to 190 ka (grey line). The plot shows the effective population size for homeland L0k as analysed by BSP (orange dashed lines). c, Southwestern hydroclimate reconstruction (shading) obtained by averaging normalized leaf wax data (MD08-3167)33 and the aridity index from cores (MD96-2094)32, for which the aridity record extended from 250 to 140 ka (grey line) and the effective population size of L0d1’2 as analysed by BSP is shown (purple dashed lines). d, Simulated LOVECLIM normalized precipitation changes (shading) northeast of the homeland (33° E, 13° S) and coalescence time probabilities for L0f haplogroup (blue bell curves). e, Same as for d, but for the homeland and coalescence probabilities for L0, L0d’k, L0a’b’f’g (black) and L0k haplogroups (orange). f, Same as for d, but for the area southwest of the homeland (17° E, 30° S) and L0d1’2 coalescence times (purple). Blue bars indicate predicted Makgadikgadi high stand phases35. NE, northeast; SW, southwest. Nature | www.nature.com | 5 2. Brown, F. 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R package version 3.3.0 https://cran.r-project.org/web/packages/maps/index.html (2018). Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. © The Author(s), under exclusive licence to Springer Nature Limited 2019 Article Methods No statistical methods were used to predetermine sample size. The experiments were not randomized and investigators were not blinded to allocation during experiments and outcome assessment. Statement on population identifiers The authors acknowledge that population identifiers (or ethnic labels) have different meanings to different peoples across different countries and between and within different ethnic groups. During the apartheid rule, South Africans were grouped according to ethnic identities, which resulted in discrimination based on population identifiers such as Bantu or Coloured. In turn, others view the very same population identifiers with cultural identity and pride. In 2013, we performed a study led by a Coloured co-author to assess the sensitivity in self-identification as Coloured. Of 521 participants, 91.2% self-identified as Coloured, Cape Coloured or South African Coloured, while 8.8% elected against the use of Coloured for self-identification14. In turn, using such population identifiers within the context of the United States would be seen as derogatory and highly offensive. We have previously genetically profiled the Baster population of Namibia13 and again what could be to others a derogatory term, to the Baster community of Rehoboth in Namibia, the term is used with immense pride, who recognize themselves as a Republic with a national flag38. In this study, the authors have used linguistics, supported by eth- nicity, to provide population identification, with further historical, geographical and genetic classification for deriving maternal contribu- tions (described in the next section). KhoeSan (or KhoeSaan) languages are grouped together due to their use of click consonants as a unique language identifier. Once spread across the entire southern African region, KhoeSan languages are today restricted largely to populations residing in Namibia and Botswana (and southern Angola), although two Tanzanian isolates, Sandawe and Hadza, are believed to be linguistically related click languages (or east African KhoeSan)39. ‘San’ literally means ‘forager’ and Khoe means ‘person’; culturally, the KhoiSan identifier refers to hunter–foragers (San) or herders (Khoi). At times linguistic and cultural identities clash. For example, Nama and Hai$om peoples both speak Nama (a Khoe–Kwadi language), while culturally and histori- cally these two populations are quite different, representing a herder and hunter-gatherer ancestry, respectively. Additionally, autosomal genetic data have been used to provide further insights into KhoeSan admixture and substructures, highlighting at a genetic level the histori- cal differences between the Nama and Hai$om40. We have attempted to capture both ethnic and linguistic identifiers that best reflect population ancestry. In contrast to KhoeSan languages, most Bantu languages do not contain click consonants; however, exceptions exist within Southern African Bantu languages (for example, isiXhosa and isiZulu languages, which have borrowed click consonants from their KhoeSan neighbours). Spoken across the entire sub-Saharan Africa (up to 500 groups), the Guthrie classification of languages further identifies the S-zone or South- ern Bantu (South Africa, Zimbabwe, southern Mozambique and most of Botswana) and the R-zone or Southwest Bantu languages (northern Namibia, southern Angola and northwest Botswana)41, which are of relevance to this study. Ethics statement and recruitment The study was performed in accordance with the ethical standards of the overseeing human research ethics committees and local govern- ance, as per the 1964 Helsinki Declaration. The study was reviewed and approved by the Ministry of Health and Social Services (MoHSS) in Namibia (17-3-3 2008, 2014 and 2019), with additional local approv- als from participating community leaders, the University of Preto- ria Human Research Ethics Committee (HREC 43/2010 and HREC 280/2017), including US Federal-wide assurance (FWA00002567 and IRB00002235 IORG0001762), as well as the South African National Blood Service (SANBS) HREC (HREC 2012/11). Participants were recruited within the borders of Namibia and South Africa and self- reported ethno-linguistic population identifiers were recorded. Blood samples were taken after receiving written and/or recorded informed consent. Isolated DNA was shipped under the Republic of South Africa Department of Health Export Permit ( J1/2/4/2), in accordance with the National Health Act 2003, to the Garvan Institute of Medical Research in Australia. Mitogenome sequencing was performed in accordance with site-specific approval granted by St Vincent’s Hospital HREC in Australia (SVH 15/227). Participant population identifiers Merging with published data for a total of 1,217 L0 mitogenomes, par- ticipants were broadly classified as KhoeSan, Bantu or Cape multi- ethnic heritage. Indigenous KhoeSan who inhabit the inland semi-desert Kalahari region of Botswana and Namibia include the Kx’a ( Ju|’hoan or Hoan, and !Xun or !Xuun), Tuu (or Taa) and Khoe–Kwadi (Naro, $Ani, Khwe, Buga, G$ana, G$ui, $Xokhoe, Tshwa and Shua) speakers. Indigenous KhoeSan who inhabit the west-coastal region of Namibia speak a Khoe–Kwadi or Nama language and include the Nama, Damara, Topnaar (ǂAonin) and Hai$om speakers42,43. Novel mitogenomes were derived from 15 Kalahari KhoeSan, including Ju|’hoan (n = 9), !Xun (n = 1) and Naro (n = 5), and 21 west-coastal KhoeSan, including Nama (n = 7), Damara (n = 8) and Topnaar (ǂAonin, n = 6) from Namibia. Speakers of southwest Bantu (non-KhoeSan) languages (which do not contain click consonants) of Namibia, Botswana and southerly boarders of Angola, presenting with KhoeSan-predominant L0 maternal lineages, most likely carry a Kalahari or west-coastal KhoeSan mitogenome. As a result of refuge provided to the Herero by the Kalahari KhoeSan during the early 1900 German South West African genocide44, we speculate in this study a probable Kalahari KhoeSan heritage for the three Herero mitogenomes. Although indigenous KhoeSan are arguably absent from the coastal regions of South Africa, and while recognising and honouring the north- west inland (southern Kalahari) ǂKhomani San of South Africa (although not recruited within the context of this study), KhoeSan skeletal remains spread across the region45. Hunter-gatherer KhoeSan once inhabited a broad southwest to east-coastal region at the tip of Africa. These skel- etal remains predate archaeological evidence supporting the arrival of sheep herders who appear to have crossed the Okavango river in northern Namibia around 2.2 ka, migrating along the southwest coast to the southern Cape12,16,20,45 by around 2 ka. Recently, Cape KhoeSan skeletons younger than 2 ka have been genetically linked to east Africa and herder migration17. Migrating herders may have acquired indig- enous KhoeSan maternal contributions. Along the east coast, southward- migrating Bantu farmers (Southern Bantu; who presumably did not speak languages containing click consonants) entered South Africa around 1,500 years ago, while a second wave of Bantu migrants (South- west Bantu) crossed central Africa into Namibia around 800 years ago12. Maternal contributions to the South African Southern-Bantu-speaking populations (n = 43, this study) may therefore either be of Bantu origin (in this case, L0a lineages and therefore non-KhoeSan) or of east-coastal KhoeSan-ancestry. The arrival of European colonists and Dutch–East- Indian slaves to the Cape in the mid-1600s, gave rise to a multi-ethnic (European, Asian, KhoeSan and Bantu) Cape population, the ancestors of the South African Coloured (n = 90, this study) and Namibian Basters (n = 24, this study), who historically speak a Dutch-derived language known as Afrikaans13,46. Emerging from a common historical background to the Coloured, the Baster population have since the late 1800s distin- guished themselves as independent from the Coloured, migrating to the Baster nation of Rehoboth in Namibia47. Although the vast majority of L0 mitogenomes represented in the Baster and Coloured popula- tions are of Cape KhoeSan heritage (100% and 94.4%, respectively), we observe a percentage of non-KhoeSan (Bantu) L0a lineages within the Coloured population. L0 haplogroup pre-screening Subjects were selected for whole-mitogenome sequencing based on pre-screening for specific L0 markers using direct amplicon-specific Sanger sequencing. Specifically, a 2,673-bp region (Cambridge Refer- ence Sequence (rCRS) position 3322–5995) was amplified and initially screened for the L0 variant T5442C. L0 samples were further screened to delineate L0d (T4232C), L0d1 (G3438A), L0d1b (T3618C), L0d1c (C4197T), L0d1’2 (A3756G), L0d2 (A3981G, C205T, A4044G), L0d2a (A5153G), L0d2d (G5147A, G5231A), L0d2C (A4038G, T4937C) and L0d3 (G5460A, G5773A) lineages. This identified 188 samples carrying a rare L0 haplogroup: L0d1b (n = 21), L0d1c (n = 13), L0d2a (n = 30), L0d2b (n = 7), L0d2c (n = 15), L0d2d (n = 6), L0d3 (n = 29), L0a1 (n = 6), L0a2 (n = 6), L0f (n = 5) and L0k (n = 5); as well as 55 samples that could not be unambiguously assigned to a major L0 sub-lineage: L0d1a’c (n = 2), L0a’b’f’k (n = 5), L0a’b (n = 2), L0d2 (n = 1) and L0d1 (n = 45, assumed L0d1a) (Supplementary Table 1). Whole-mitogenome sequencing Mitogenomes were isolated using two overlapping amplicons as previ- ously described6,48. Specifically, two primer pairs were used to isolate and amplify fragments 12,250–3,005 (7.2 kb) and 2,583–12,337 (9.7 kb) of the circular mitogenome. This pair of primers has been demonstrated to effectively capture the mitogenome with high specificity while mini- mizing off-target capture of nuclear copies of mitochondrial-derived DNA. Following touchdown long-range amplification with the Platinum Taq DNA Polymerase High Fidelity (Invitrogen), the two amplicons were purified using AMPure XP beads (Agencourt) and combined in a 7:13 ratio of short:long fragments. Sequencing was performed on the Ion Torrent PGM platform. In brief, 200-bp single-end sequencing libraries were prepared using the Ion Xpress Plus Fragment Kit and Ion Xpress Barcode Adaptors (ThermoFisher), and 4–16 samples (barcodes) were pooled and sequenced on 314v2 Ion Chips. Using the Ion Torrent suite v.5.0.2.1, sequencing reads were quality trimmed and aligned to the human mitochondrial revised rCRS (accession NC_012920.1). Consensus mitogenome sequences were derived by first identifying variants relative to rCRS, using samtools (v.1.3.1) mpileup (with parameters -d 10000 -L 1000 -Q 7 -h 50 -o 10 -e 17 -m 4)49 and bcftools (v.1.3.1) call (with param- eters -c -M) (http://www.htslib.org/doc/bcftools.html), then converting to the FASTA format using the vcfutils.pl vcf2fq program in samtools. Publicly available data An exhaustive search for publicly available L0 mitogenomes was per- formed between 2015 and 2017, identifying 26 studies comprising a total of 6,334 mitogenomes. L0 status for all mitogenomes was deduced, either directly from the original publication or by downloading the nucleotide sequences from NCBI and evaluating their haplogroup using HaploGrep2 (v.2.1.13)50 based on PhyloTree Build 1751. From this dataset, a subset of 1,019 L0 mitogenomes was identified and included in this study (Extended Data Table 1 and Supplementary Table 2). Publicly available genomes were broadly classified as KhoeSan, Bantu (KhoeSan ancestral), or non-KhoeSan based on the reported population and/or country of origin. Whole-mitogenome haplotyping HaploGrep250 was used to type all 1,217 sequences against PhyloTree Build 1751. This resulted in the refinement and reclassification of our 198 mitogenomes, resulting in L0d1 (n = 81, including 45 L0d1a, 21 L0d1b, 13 L0d1c and 2 L0d1d), L0d2 (n = 58, including 30 L0d2a, 8 L0d2b, 14 L0d2c and 6 L0d2d), L0d3 (n = 27), L0a (n = 19), L0f (n = 5), L0k (n = 5) and L0g (n = 3) mitogenomes (Supplementary Table 1). This refined, and in some cases reclassified, the haplogroups of the 1,019 publicly available mitogenomes (Supplementary Table 2). Phylogenetic inference Multiple sequence alignment was performed across all 1,217 mitog- enomes along with 7 Neanderthal genomes (Supplementary Table 10), using MUSCLE v.3.8.3152 with parameters -maxiters 3 -diags1. Phylo- genetic inference was performed using FastTree v.2.1.7 (SSE3)53 using the generalized time reversible (-gtr) and discrete gamma model with 20 rate categories (-gamma). A summary of the inferred phylogenetic tree is shown in Extended Data Fig. 1, with the tree rerooted to the 7 Neanderthal genomes. Bayesian phylogenetic inferences and divergence times were calcu- lated using BEAST2 v.2.4.2 with BEAGLE v.2.054. Owing to the compu- tational burden of this analysis, BEAST was performed on a subset of 461 mitogenomes, selected to include: (i) only complete mitogenomes (27 mitogenomes with only the coding region55,56 were excluded); (ii) all 198 novel mitogenomes from this study; (iii) all 121 L0 mitogenomes from our previous studies, Chan et al.6 (n = 77), Morris et al.15 (StHe, defining the new haplogroup L0d2c1c), McCrow et al.48 (n = 37) and Schuster et al.57 (n = 6); (iv) all rare haplogroups, namely L0g (n = 9), L0f (n = 22), L0d3 (n = 30), L0d1d (n = 3), L0d2d (n = 11) and L0k2 (n = 12); (v) all mitogenomes that could not be unambiguously typed by HaploGrep250 (n = 14; none from this study); and (vi) a random subset of mitogenomes for all remaining sub-lineages not already represented. Multiple sequence alignment of the subset of 461 AMH and 7 Nean- derthal mitogenomes was converted to NEXUS format using the con- vert function of seqmagick v.0.6.1 (https://fhcrc.github.io/seqmagick) with parameter --alphabet dna-ambiguous. This provided the input to BEAST2. Specifically, BEAUTi v.2.4.2 was used to set up the phylo- genetic model, assuming: (i) the gamma site model with six gamma categories and no invariant sites; (ii) the generalized time-reversible substitution model; (iii) a strict constant clock model with a normal prior with µ = 1.665 × 10−8 and σ = 1.479 × 10−9 based on a previously published study58; and (iv) a coalescent constant population. Times were calibrated to the seven H. neanderthalensis mitogenomes with tip dates set to their reported approximate archaeological dating estimates: Feldhofer 1, 40 ka59; Vindija, 38 ka59; El Sidron, 39 ka59; Feldhofer 2, 40 ka59; Mezmais- kaya, 65 ka59; Croatia, 38.31 ka60; Altai, 50 ka61 (Supplementary Table 10). No prior was set on the most recent common ancestor of this taxon set, and calibration was applied to the leaves instead of the most recent common ancestor. Further, a normal prior, N(µ = 200,000, σ = 50,000), was set on the coalescent time of the AMH genomes, and a tip date of 2,330 years before present was set for the StHe genome15. Five BEAST replicates were performed, each with 100 million Markov chain Monte Carlo iterations, sampling every 10,000. Tracer v.1.6 was used to evaluate BEAST trace files (Supplementary Table 11), ensuring all runs had converged. The five replicates were combined using LogCom- biner v.2.4.2, discarding 10% of the samples as burn-in for each replicate and without resampling states at a lower frequency. Sampled trees from BEAST were summarized into a single maximum clade credibility target tree using TreeAnnotator v.2.4.2 for each of the five replicates, discarding the first 10% as burn-in. To summarize across replicates, sampled trees from the five replicates were first combined using LogCombiner v.2.4.2, again discarding the first 10% as burn-in from each replicate, but resampling at a lower frequency of 50,000 (five replicates of 10,000 samples). The combined, resampled trees were then summarized with TreeAnnotator v.2.4.2 as for the individual replicate BEAST results. FigTree v.1.4.2+ (http://tree.bio.ed.ac.uk/software/figtree/) was used to visualize all resulting trees. BSP analysis BSP analyses were performed to estimate the demographic history of each maternal haplogroup. Although maternal haplogroups do not necessarily equate to population groups, it has been suggested that the signal associated with a haplogroup can still provide insights into the demographic processes in the populations who carry the haplogroup62,63. For each haplogroup of interest (for example, L0a, L0d1’2 and L0k), a nexus file was derived using SeqMagic v.0.6.1 as described above. Article BSP analyses were performed using BEAST2, using BEAUTi 2 for model setup as described in ‘Phylogenetic inference’, with the following key differences: (i) the gamma shape of the gamma site model was esti- mated with an exponential prior with mean = 1.0 and offset = 0.0; (ii) the molecular clock was fixed (not estimated) at 1.665 × 10−8 based on a previously published study58; and (iii) the phylogenetic tree prior was set to coalescent Bayesian skyline, assuming 20 intervals between the root of the tree and the present time. Tracer v.1.6 was used to reconstruct the Bayesian skyline from the sampled trees for each analysis, using a stepwise constant variant and the lower 95% highest posterior density of the root height as the maximum time. Results of this analysis are summarized in Supplementary Table 12. Geographical history of the palaeo-wetland Makgadigadi Initiated around 2 million years ago, palaeo-lake Makgadikgadi7 origi- nally covered an area of around 170,000 km2 at its highest lake stand, bounded by a shoreline of around 995 m. A degraded sand ridge (the Deception ridge), was associated with the 995-m shore in the southwest of the lake. This lake would have covered more than twice the area of modern Lake Victoria, and similar to the latter, would have caused a con- siderable climatic feedback, with locally enhanced rainfall. We previously proposed that this was, in turn, responsible for the initiation of the sur- rounding (now-fossil) drainages, creating a well-watered environment and very favourable habitat for mammals, including hominids7. Smaller lakes, now represented by residual wetlands, also formed on the upper Zambezi river and the modern Kafue Flats on the Kafue river, resulting in an archipelago of palaeo-lakes in south-central Africa during the Early and Middle Pleistocene epoch. Palaeo-Makgadikgadi, bounded by the 995-m shoreline, was originally sustained by a major drainage line, which included the Chambeshi river as headwaters, connected to the upper Zambezi river via the upper Kafue river. Severance of the original links between the Chambeshi river and upper Kafue river, and the latter and the upper Zambezi river resulted in a sequential contraction of the Makgadikgadi to a much smaller water body. This is reflected in a series of fossil shorelines, associated with breaks in slope, at progressively lower levels (945 m, 936 m and 922 m). The Gidikwe ridge was associated with the 945-m shoreline. However, contraction of the lake was accompanied by the development of the modern Okavango delta. Timing of the contraction of the lake and initiation of the Okavango delta is not tightly constrained, but by the time that we propose that modern humans emerge within the region, around 200 ka, we speculate that the formerly extensive Makgadikgadi palaeo-lake had contracted to a much less extensive deltaic–lacustrine system. Together with the lakes that developed from the upper Zambezi and Kafue rivers to the north and the Okavango delta to the west, the region would have been a vast wetland, a favourable habitat for homi- nid occupation. It is this palaeo-wetland region that we propose as the homeland for the founder population of AMHs. Climate model simulations and palaeo-climate data To place the coalescence time estimates of the L0 branch into a cli- matic context and to test the robustness of simulated hydroclimate responses in South Africa to orbital-scale conditions, we use the LOVE- CLIM Earth system model of intermediate complexity28. It is based on a 3-layer atmosphere, a 20-level ocean general circulation model, a dynamic–thermodynamic sea–ice model and a terrestrial vegetation model. A transient simulation that covers several glacial–interglacial cycles was conducted using time-dependent boundary conditions. The experiment28 (covering the past 784 kyr) uses time-varying bound- ary conditions for orbital parameters, CO2 and other greenhouse gas concentrations obtained from Antarctic ice cores, and an estimate of Northern Hemispheric ice-sheet orography and albedo changes (data are used in Fig. 3 and Extended Data Fig. 6). The forcings are applied with an acceleration factor of five: one coupled model year corresponds to five orbital calendar years. Our analysis focuses on the past 250 kyr in both simulations. The climate sensitivity of this model to CO2 variations was modified to capture the range of reconstructed global mean surface temperature changes in response to radiative forcing64. The transient LOVECLIM model simulations have previously been validated against other palaeo-climate records from around the world28,64,65. Our analysis here focuses on the simulated precipitation as well as changes in tree and grass fractions in central eastern Africa and western southern Africa (data used in Fig. 3 d–f and Extended Data Fig. 6b–d). As a result of its coarse horizontal atmospheric resolution (5.6°) and the use of only parameterized ageostrophic wind components, LOVE- CLIM has several deficiencies. Of particular note are the lack of realistic El Niño–Southern Oscillation variability and the fact that annual mean freshwater flux corrections have been applied to mimic the atmospheric moisture transport from the Atlantic to the Pacific and to stabilize the Atlantic Meridional Overturning Circulation. There exist only a few long-term hydroclimate datasets from southern Africa that cover the past >120 kyr. Here we compare the simulated LOVE- CLIM precipitation (normalized) in central southern Africa with a south- ern central African hydroclimate composite, obtained by averaging the normalized orbitally tuned rainfall reconstruction from the Pretoria salt pan29 and the normalized Fe/K river run-off proxy obtained from marine sediment core CD154-1006P31 (Fig. 3b). The composite index emphasizes the joint variability in both records. We find that some of the overall fea- tures in the observations—particularly the fact that rainfall is modulated by the precessional cycle of austral summer insolation66 (Fig. 3a)—are well-captured by the LOVECLIM model experiment. However, we also find some discrepancies in the central part of southern Africa, such as in the phase of the precessional signal and the difference in overall wet and dry conditions during the homeland period from 200 to 120 ka. The overall glacial drying in the central part of southern Africa from 100 to 20 ka is, however, captured in both model simulation and palaeo-proxy recon- structions (Fig. 3b, e). Orbital-scale hydroclimate variations in southern Africa are clearly not spatially homogenous (Fig. 3b–f). To gain a better understanding of the spatial patterns of hydroclimate variability, we com- pared the model simulation with a composite index from southwestern Africa, obtained by averaging a normalized aridity index reconstructed from sediment core MD96-209433 and the normalized δ13C isotope ratio data of leaf wax extracted from the South Atlantic sediment core MD08- 316732 (Fig. 3c and Extended Data Fig. 6c, d). The results show a good correspondence between model and reconstructions on the western side of southern Africa, and in particular reproduce a major drought period that peaked around 120 ka and a subsequent increase in rainfall towards the last glacial period. This gradual increase in rainfall corresponds to an overall increase in lineage splitting of the L0d1’2 haplogroup (Fig. 3f) and growth of its population (Fig. 3c). This result further highlights the possibility that climate shifts may have played an important part in the southwestward migration of L0d1’2 descendants (Fig. 2). To further test the fidelity of LOVECLIM in reproducing interhemi- spheric orbital rainfall shifts across Africa, we also compared the simu- lated vegetation changes with a leaf-wax index from stable hydrogen isotope data extracted from a sediment core in the Gulf of Aden30, which is indicative of hydroclimate and vegetation changes in the northeast- ern Horn of Africa (Extended Data Fig. 6b). The comparison shows a good qualitative correspondence for the precessional-scale timing of rainfall and vegetation maxima and minima as well as of the eccentric- ity modulated amplitude of these changes, lending further support to the credibility of the simulated rainfall patterns across Africa. It should be noted that regional patterns of paleo-rainfall changes are in general difficult to simulate. In response to Last Glacial Maximum boundary conditions, different coupled general circulation models simulate widely varying responses in rainfall over Africa28. Reporting summary Further information on research design is available in the Nature Research Reporting Summary linked to this paper. Data availability The consensus sequences for this set of 198 mitogenomes have been deposited in the NCBI GenBank with accession numbers MK248274– MK248471. Requests for materials should in the first instance be addressed to V.M.H. 38. Orizio, R. 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Oosthuysen, D. Roux, C. Swau and T. Tsebe. We acknowledge the late M. McFarlane, who identified Deception ridge and its importance in the evolution of the Makgadikgadi palaeo-lake. This work was supported by an Australian Research Council Discovery Project grant awarded to V.M.H. (DP170103071) and sampling contributed by the Cancer Association of South Africa to M.S.R.B. and V.M.H. A.T. and S.-S.L. received funding from the Institute for Basic Science (IBS) under IBS-R028-D1. V.M.H. is supported by the University of Sydney Foundation in a Petre Foundation chair position. Computational resources were provided by the Australian Government through the National Computational Infrastructure, the Sydney Informatics Research Hub at the University of Sydney (Artemis HPC) and by the Garvan Institute of Medical Research Data Intensive Computer Engineering team. Author contributions V.M.H. designed the study. M.S.R.B., H.E.A.F. and V.M.H. obtained and maintain study approvals and permits, as well as community leadership support. M.S.R.B., D.C.P. and V.M.H. performed recruitments, consenting, sampling and processing. R.J.L., A.M.F.K. and D.C.P. performed pre-screening and mitogenome data generation. E.K.F.C. performed the bioinformatics and phylogenetic analyses. A.E.M. performed geographical interpretation. S.-S.L. and A.T. performed climatological model analyses and interpretation, with additional local climatology interpretation provided by H.R. V.M.H. led the interpretation of the multiple-discipline analyses, with contributions from all of the authors. E.K.F.C., B.F.B., S.-S.L., A.T. and V.M.H. generated and interpreted the figures. V.M.H., E.K.F.C. and A.T. wrote the manuscript with contributions from all of the authors. Competing interests The authors declare no competing interests. Additional information Supplementary information is available for this paper at https://doi.org/10.1038/s41586-019- 1714-1. Correspondence and requests for materials should be addressed to A.T. or V.M.H. Peer review information Nature thanks Victor Brovkin, Rebecca Cann and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Reprints and permissions information is available at http://www.nature.com/reprints. Article Extended Data Fig. 1 | Phylogenetic tree of all 1,217 L0 mitogenomes. Phylogeny was inferred using FastTree v.2.1.746, displayed using FigTree. Tips belonging to the same haplogroup are collapsed and coloured as in Fig. 2a. Local support values for each node are indicated and branch lengths are proportional to the number of substitutions per site. The tree is rooted to the seven Neanderthal mitogenomes as indicated. Extended Data Fig. 2 | Detailed phylogenetic branching of L0k, L0d3, L0f and L0g. a–d, Expanded sections of the phylogenetic tree depicted in Fig. 2a are shown, including 34 (out of a total of 113) L0k (a), all 40 L0d3 (b), all 27 L0f (c) and all 9 L0g (d) mitogenomes. Each mitogenome is represented as a tip and coloured based on their broad ethno-linguistic classification, if known. KhoeSan is shown in orange, non-KhoeSan in grey and Cape multi-ethnic (KhoeSan ancestral) in green. Publicly available mitogenomes for which we cannot be certain of their broad population identifier are labelled in black font. Proposed new sub-lineages for L0d3, L0f and L0g1 are indicated by red-coloured node labels and are further described in Supplementary Tables 7–9. Article Extended Data Fig. 3 | Detailed phylogenetic branching of L0d2. a, c, d, Expanded branches of the phylogenetic tree depicted in Fig. 2a are shown, including 51 (out of a total of 118) L0d2a (a), 25 (out of 53) L0d2c (c) and all 11 L0d2d (d) mitogenomes. b, For L0d2b, an additional BEAST analysis was performed using an alternate subset of 441 mitogenomes that included all 43 L0d2b samples, as opposed to the n = 461 subset (Fig. 2a) that included only 13 L0d2b. The same model parameters were used for both data subsets. In all panels, each mitogenome is represented as a tip and coloured based on their broad ethno-linguistic classification, as in Extended Data Fig. 2. The previously defined L0d2c1c haplogroup, containing the coastal KhoeSan StHe skeleton6 and other newly proposed sub-lineages are indicated by red node labels (Supplementary Tables 4–6). Extended Data Fig. 4 | Detailed phylogenetic branching of L0d1. a–c, Expanded branches of the phylogenetic tree depicted in Fig. 2a are shown, including 54 (out of a total of 91) L0d1a (a), 45 (out of 174) L0d1b (b) and 33 (out of 184) L0d1c (c) mitogenomes. Each mitogenome is represented as tips and coloured based on their broad ethno-linguistic classification as in Extended Data Fig. 2. Article Extended Data Fig. 5 | Detailed phylogenetic branching of L0a. The L0a branch of the phylogenetic tree displayed in Fig. 2a is shown, which includes a subset of 114 (out of a total of 294) L0a mitogenomes. Each mitogenome is represented as tips and coloured based on their broad ethno-linguistic classification as in Extended Data Fig. 2. Extended Data Fig. 6 | Comparison of the palaeo-data and palaeo-model. a, Locations of key sites that are used for the comparison of the palaeo-model and palaeo-data in this study are highlighted in red. The map was generated in Paraview v.5.6 (https://www.paraview.org/). b, Simulated tree fraction (%) at Horn of Africa (land grid points nearest to RC09-166) (grey, dark-blue bars) and stable hydrogen isotopic composition of leaf wax, corrected for ice volume contributions from the Gulf of Aden marine sediment core RC09-16630 (orange), indicating changes in hydroclimate. c, Relative precipitation changes (%) simulated by LOVECLIM transient model (all forcings) for 11° E, 19° S (grey, dark- blue bars) and grain-size aridity index reconstructed from sediment core MD96- 209432 (orange). d, Grass fraction changes simulated by LOVECLIM transient model (all forcings) at 11° E, 14–17° S (grey, dark-blue bars) and reconstructed δ13C changes of n-alkanes (orange) (South Atlantic sediment core MD08-3167) indicative of abundance of C3 and C4 plants in the Namibian desert and further inland33. Article Extended Data Table 1 | L0 mitogenomes included in this study Numbers of mitogenomes taken from previously published67–83 studies. *Previously published data by our group with verified population metadata. †Mitochondrial DNA sequences of the coding-region only. ‡Sequence has non-canonical start position corresponding to position 577 of rCRS. §Coriell cell lines. Extended Data Table 2 | KhoeSan population identifiers used in this study