Hunting behavior and strategies of the Valley Bisa in Zambia

This article describes the hunting tactics and prey selection of the Valley Bisa, a matrilineal, subsistence-oriented society in the Luangwa Valley of Zambia. Although Valley Bisa hunters explain their behavior in their own idioms, many of their tactics, including the stimuli for and timing of hunts, the circular morphology of their hunting patterns, and randomized searches, appear functionally related to the behavior and ecology of their prey. The effects of outlawing traditional harvest techniques and the imposition and enforcement of external constraints on Valley Bisa hunting patterns are discussed. Data on habitats, density of cover, wind direction, species, and initial distance to prey from 50 hunts, in which 16 mammals were killed, are compared and related to success and failure of stalking attempts. Graphs, comparing the numbers of observations for each of four variables with the frequency of stalking attempts, illustrate the cultural style of predation for this group of hunters.This article was initially presented as part of my contribution to a graduate seminar, Public Management of the African Environment, African Studies Program, Indiana University, October 9, 1975. I wish to thank Professor J. Gus Liebenow for extending the invitation to participate in this program.     

Prey selection and annual harvest of game in a rural Zambian community

The selection and hunting patterns of Valley Bisa hunters were studied as part of a broader ecological investigation of human communities between the two sections of the Luangwa Valley Game Reserves in Zambia. This article provides information on the frequency and duration of hunts recorded for 1 year, yields of individual hunters, prey selection, frequency of kill, community meat supplies and the effect of human and carnivore predation on population levels on a study area of some 155 km². Individuals who hunted were classified into four categories–resident, transient, occasional, and official, dependent upon their role in the community, length of time spent on the study area and their village of primary residence. The most frequent hunters were residents followed in rank order by officials, transients and occasionals. Hunts were of shorter duration during the dry season, when game was close to villages, than during the wet season. Generally hunters who owned or had access to modern weapons were more successful in their pursuits of game than were those who used muzzle-loading guns. A total of 27 451 kg of meat (carcass yield) was made available to 466 local residents during the course of the year; 40% of this was attributed to the activities of the game guards. Valley Bisa hunters killed primarily buffalo, impala, warthogs, and waterbuck; most of these were males and adults. The kills recorded for carnivores suggest that they took primarily female buffalo and zebra. There was no evidence to suggest that either type of predation was damaging to the game herds on the study area.     

The Bantu expansion revisited: a new analysis of Y chromosome variation in Central Western Africa

The current distribution of Bantu languages is commonly considered to be a consequence of a relatively recent population expansion (3-5kya) in Central Western Africa. While there is a substantial consensus regarding the centre of origin of Bantu languages (the Benue River Valley, between South East Nigeria and Western Cameroon), the identification of the area from where the population expansion actually started, the relation between the processes leading to the spread of languages and peoples and the relevance of local migratory events remain controversial. In order to shed new light on these aspects, we studied Y chromosome variation in a broad dataset of populations encompassing Nigeria, Cameroon, Gabon and Congo. Our results evidence an evolutionary scenario which is more complex than had been previously thought, pointing to a marked differentiation of Cameroonian populations from the rest of the dataset. In fact, in contrast with the current view of Bantu speakers as a homogeneous group of populations, we observed an unexpectedly high level of interpopulation genetic heterogeneity and highlighted previously undetected diversity for lineages associated with the diffusion of Bantu languages (E1b1a (M2) sub-branches). We also detected substantial differences in local demographic histories, which concord with the hypotheses regarding an early diffusion of Bantu languages into the forest area and a subsequent demographic expansion and migration towards eastern and western Africa.     

mtDNA variability in two Bantu‐speaking populations (Shona and Hutu) from Eastern Africa: Implications for peopling and migration patterns in sub‐Saharan Africa

In this study, we report novel data on mitochondrial DNA in two of the largest eastern Bantu‐speaking populations, the Shona from Zimbabwe and the Hutu from Rwanda. The goal is to evaluate the genetic relationships of these two ethnic groups with other Bantu‐speaking populations. Moreover, by comparing our data with those from other Niger‐Congo speaking populations, we aim to clarify some aspects of evolutionary and demographic processes accompanying the spread of Bantu languages in sub‐Saharan Africa and to test if patterns of genetic variation fit with models of population expansion based on linguistic and archeological data. The results indicate that the Shona and Hutu are closely related to the other Bantu‐speaking populations. However, there are some differences in haplogroup composition between the two populations, mainly due to different genetic contributions from neighboring populations. This result is confirmed by estimates of migration rates which show high levels of gene flow not only between pairs of Bantu‐speaking populations, but also between Bantu and non‐Bantu speakers. The observed pattern of genetic variability (high genetic homogeneity and high levels of gene flow) supports a linguistic model suggesting a gradual spread of Bantu‐speakers, with strong interactions between the different lines of Bantu‐speaker descent, and is also in agreement with recent archeological findings. In conclusion, our data emphasize the role that population admixture has played at different times and to varying degrees in the dispersal of Bantu languages. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

Patterns of depletion in a black rhinoceros population in Luangwa Valley, Zambia

Black rhinos in Luangwa Valley, Zambia have been subjected to heavy illegal hunting since the late 1970s. A study population monitored by individual recognition decreased at an instantaneous rate of - 0.29 yr^-1 between 1981 and 1985. Two-thirds of skulls found throughout Luangwa Valley between 1979 and 1985 were axed, indicating death from poaching. All age- and sex-classes of rhino were equally susceptible to being shot, presumably due to the high market-price of rhino horn.     

Y-chromosomal variation in sub-Saharan Africa: insights into the history of Niger-Congo groups

Technological and cultural innovations as well as climate changes are thought to have influenced the diffusion of major language phyla in sub-Saharan Africa. The most widespread and the richest in diversity is the Niger-Congo phylum, thought to have originated in West Africa ～ 10,000 years ago (ya). The expansion of Bantu languages (a family within the Niger-Congo phylum) ～ 5,000 ya represents a major event in the past demography of the continent. Many previous studies on Y chromosomal variation in Africa associated the Bantu expansion with haplogroup E1b1a (and sometimes its sublineage E1b1a7). However, the distribution of these two lineages extends far beyond the area occupied nowadays by Bantu-speaking people, raising questions on the actual genetic structure behind this expansion. To address these issues, we directly genotyped 31 biallelic markers and 12 microsatellites on the Y chromosome in 1,195 individuals of African ancestry focusing on areas that were previously poorly characterized (Botswana, Burkina Faso, Democratic Republic of Congo, and Zambia). With the inclusion of published data, we analyzed 2,736 individuals from 26 groups representing all linguistic phyla and covering a large portion of sub-Saharan Africa. Within the Niger-Congo phylum, we ascertain for the first time differences in haplogroup composition between Bantu and non-Bantu groups via two markers (U174 and U175) on the background of haplogroup E1b1a (and E1b1a7), which were directly genotyped in our samples and for which genotypes were inferred from published data using linear discriminant analysis on short tandem repeat (STR) haplotypes. No reduction in STR diversity levels was found across the Bantu groups, suggesting the absence of serial founder effects. In addition, the homogeneity of haplogroup composition and pattern of haplotype sharing between Western and Eastern Bantu groups suggests that their expansion throughout sub-Saharan Africa reflects a rapid spread followed by backward and forward migrations. Overall, we found that linguistic affiliations played a notable role in shaping sub-Saharan African Y chromosomal diversity, although the impact of geography is clearly discernible.     

The dating and interpretation of a Mode 1 site in the Luangwa Valley, Zambia

Flake based assemblages (Mode 1) comprise the earliest stone technologies known, with well-dated Oldowan sites occurring in eastern Africa between ∼ 2.6-1.7 Ma, and in less securely dated contexts in central, southern and northern Africa. Our understanding of the spread and local development of this technology outside East Africa remains hampered by the lack of reliable numerical dating techniques applicable to non-volcanic deposits. This study applied the still relatively new technique of cosmogenic nuclide burial dating (¹⁰Be/²⁶Al) to calculate burial ages for fluvial gravels containing Mode 1 artefacts in the Luangwa Valley, Zambia. The Manzi River, a tributary of the Luangwa River, has exposed a 4.7 m deep section of fluvial sands with discontinuous but stratified gravel layers bearing Mode 1, possibly Oldowan, artefacts in the basal layers. An unconformity divides the Manzi section, separating Mode 1 deposits from overlying gravels containing Mode 3 (Middle Stone Age) artefacts. No diagnostic Mode 2 (Acheulean) artefacts were found.Cosmogenic nuclide burial dating was attempted for the basal gravels as well as exposure ages for the upper Mode 3 gravels, but was unsuccessful. The complex depositional history of the site prevented the calculation of reliable age models. A relative chronology for the full Manzi sequence was constructed, however, from the magnetostratigraphy of the deposit (N>R>N sequence). Isothermal thermoluminescence (ITL) dating of the upper Mode 3 layers also provided consistent results (∼78 ka). A coarse but chronologically coherent sequence now exists for the Manzi section with the unconformity separating probable mid- or early Pleistocene deposits below from late Pleistocene deposits above. The results suggest Mode 1 technology in the Luangwa Valley may post-date the Oldowan in eastern and southern Africa. The dating programme has contributed to a clearer understanding of the geomorphological processes that have shaped the valley and structured its archaeological record.     

Mitochondrial DNA analyses show that Zambia's South Luangwa Valley giraffe (Giraffa camelopardalis thornicrofti) are genetically isolated

Thornicroft's giraffe, Giraffa camelopardalis thornicrofti, is a geographically isolated subspecies of giraffe found only in north‐east Zambia. The population only occurs in Zambia's South Luangwa Valley, an area which interestingly places it between the current distribution of Masai (G. c. tippelskirchi) giraffe to the north, and the Angolan (G. c. angolensis) and South African (G. c. giraffa) giraffe in the south‐west and south, respectively. Specific studies have been undertaken on the ecology of this subspecies, but their population genetics remains unknown. We studied 34 individuals from the South Luangwa National Park and adjacent Lupande Game Management Area and seven individuals from northern Botswana. The complete cytochrome b and control region sequences of the mitochondrial genome were sequenced and analysed together with database data by maximum likelihood tree reconstruction and maximum parsimony network analyses. The giraffe from Zambia's South Luangwa Valley are most closely related to the subspecies G. c. tippelskirchi and part of their radiation. However, they form a unique population that would benefit from increased research and conservation management.     

Seasonal and geographical influences on the feeding ecology of giraffes in the Luangwa Valley,Zambia: 1973–2014

Obtaining longitudinal data about the feeding ecology of long‐lived iteroparous mammals is rare, but enhances our understanding of how the environment influences niche breadth and dietary diversity within a species. We analysed forty years of feeding records obtained from a population of Thornicroft's giraffes (Giraffa camelopardalis thornicrofti) living in the Luangwa Valley, Zambia. Giraffes are browsers that have been reported to feed primarily upon Acacia leaves, but their feeding ecology in some locations conflict with this interpretation. Giraffes in the Luangwa Valley fed on 93 identified plant species, but only a few contributed to the bulk of the diet. Niche breadth was quite large (Shannon‐Weiner Diversity Index H′ = 3.699) and about 13% more diverse during the dry, than wet, season. Key species eaten during the dry season were very consistent across decades, with Kigelia africana and Capparis tomentosa prominent at this time. The evolutionary ecology of giraffes has probably benefitted from a foraging strategy that includes a variable and high‐quality diet during the hot, dry season, when feeding pressures are greatest. Giraffe feeding ecology has evolved in conjunction with their physiology, anatomy and morphology, resulting in an animal that is well adapted for survival in an arid environment.     

The composition and function of all‐male herds of Thornicroft's giraffe,Giraffa camelopardalis thornicrofti,in Zambia

Temporary all‐male social groups are formed in a number of animal species. We examined 34 years of data collected from 36 male Thornicroft's giraffe in the Luangwa Valley, Zambia, to test a set of predictions related to five possible functions of all‐male herds (predator protection, practicing aggressive skills, prolonging life, nutritional demands and resource learning). We found that all‐male herds were significantly smaller than mixed‐sex herds, usually contained a mature bull, and were not dependent upon season or habitat. Dyadic associations between males in single sex herds were quite weak, with <25% of potential male dyads sighted together in an all‐male herd. Our data are best explained as a resource learning strategy adopted by males to obtain more extensive knowledge about the habitat, including both food and female distribution. However, other benefits in the form of predator protection, dietary intake and sharpening competitive skills for future contests over estrous females also seem to mediate formation of giraffe all‐male groups. We conclude that the primary advantage of roaming in all‐male herds changes during the life history of males.     

The elephant problem–an alternative hypothesis

Published hypotheses to account for habitat changes wrought by elephants begin from the assumption that elephant-forest systems possess a stable equilibrium point. The ‘elephant problem’ is conceived as a displacement of this equilibrium by man. Controversy centres around which human activities caused the dislocation of equilibrium and by which mechanisms these activities resulted in local high densities of the elephant Loxodonta africana. A study on elephant-forest relationships in the Luangwa Valley of Zambia casts doubt upon the basic assumption of these hypotheses and an alternative hypothesis is therefore offered. It begins from the opposite assumption–that there is no attainable natural equilibrium between elephants and forests in eastern and southern Africa. The relationship is viewed instead as a stable limit cycle in which elephants increase while thinning the forest and decline until reaching a low density that allows resurgence of the forest. This in turn triggers an increase of elephants and the cycle repeats. The period of the cycle, if the hypothesis is correct, is in the order of 200 years in the Luangwa Valley. The activities of man can impose an artificial equilibrium on the system such that trees and elephants are trapped at the low density phase of the cycle. When interference is relaxed, as with the conversion of an area to a national park, the cyclic relationship reasserts. The parameters of a system possessing a stable limit cycle need not differ in kind or interrelationship from those of a system with a stable equilibrium. Whether one or other outcome manifests may depend only on the numerical values of the parameters. If the elephant-forest system is characterized by a stable limit cycle the period and amplitude should change along a climatic gradient and may contract to a stable equilibrium in some climatic zones. A set of predictions is offered to facilitate rejection of the hypothesis.     

Population structure of a vector of human diseases: Aedes aegypti in its ancestral range,Africa

Aedes aegypti, the major vector of dengue, yellow fever, chikungunya, and Zika viruses, remains of great medical and public health concern. There is little doubt that the ancestral home of the species is Africa. This mosquito invaded the New World 400‐500 years ago and later, Asia. However, little is known about the genetic structure and history of Ae. aegypti across Africa, as well as the possible origin(s) of the New World invasion. Here, we use ~17,000 genome‐wide single nucleotide polymorphisms (SNPs) to characterize a heretofore undocumented complex picture of this mosquito across its ancestral range in Africa. We find signatures of human‐assisted migrations, connectivity across long distances in sylvan populations, and of local admixture between domestic and sylvan populations. Finally, through a phylogenetic analysis combined with the genetic structure analyses, we suggest West Africa and especially Angola as the source of the New World's invasion, a scenario that fits well with the historic record of 16th‐century slave trade between Africa and Americas.     

Unraveling the complex maternal history of Southern African Khoisan populations

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. Am J Phys Anthropol 153:435–448, 2014. © 2013 Wiley Periodicals, Inc.     

Variation of female and male lineages in sub-Saharan populations: the importance of sociocultural factors

In this paper, we present a study of genetic variation in sub-Saharan Africa, which is based on published and unpublished data on fast-evolving (hypervariable region 1 of mitochondrial DNA and six microsatellites of Y chromosome) and slow-evolving (haplogroup frequencies) polymorphisms of mtDNA and Y chromosome. Our study reveals a striking difference in the genetic structure of food-producer (Bantu and Sudanic speakers) and hunter-gatherer populations (Pygmies, Kung, and Hadza). In fact, the ratio of mtDNA to Y-chromosome Nupsilon is substantially higher in food producers than in hunter-gatherers as determined by fast-evolving polymorphisms (1.76 versus 0.11). This finding indicates that the two population groups differ substantially in female and male migration rate and/or effective size. The difference also persists when linguistically homogeneous populations are used and outlier populations are eliminated (1.78 vs 0.19) or when the jacknife procedure is applied to a paired population data set (1.32 to 7.84 versus 0.14 to 0.66). The higher ratio of mtDNA to Y-chromosome Nnu in food producers than in hunter-gatherers is further confirmed by the use of slow-evolving polymorphisms (1.59 to 7.91 versus 0.12 to 0.35). To explain these results, we propose a model that integrates demographic and genetic aspects and incorporates ethnographic knowledge. In such a model, the asymmetric gene flow, polyginy, and patrilocality play an important role in differentiating the genetic structure of sub-Saharan populations. The existence of an asymmetric gene flow is supported by the phylogeographic features of mtDNA and Y-chromosome haplogroups found in the two population groups. The role of polyginy and patrilocality is sustained by the evidence of a differential pressure of genetic drift and gene flow on maternal and paternal lineages of food producers and hunter-gatherers that is revealed through the analysis of mitochondrial and Y-chromosomal intrapopulational variation.     

Applying computer‐aided photo‐identification to messy datasets: a case study of Thornicroft's giraffe (Giraffa camelopardalis thornicrofti)

Digital photography enables researchers to rapidly compile large quantities of data from individually identifiable animals, and computer software improves the management of such large datasets while aiding the identification process. Wild‐ID software has performed well with uniform datasets controlling for angle and portion of the animal photographed; however, few datasets are collected under such controlled conditions. We examined the effectiveness of Wild‐ID in identifying individual Thornicroft's giraffe from a dataset of photographs (n = 552) collected opportunistically in the Luangwa Valley, Zambia from March to October 2009. We assessed the programme's accuracy in correctly identifying individuals and the effect of five image quality factors on identification success: blurriness, background type and complexity, amount of sky and the presence of other giraffe. The programme correctly identified individuals in 71.6% of photographs. Background complexity was the only significant variable affecting identification success and removing background imagery reduced identification error by 52.8% (from 28.4 to 13.4%). Our results indicate higher levels of error than previously reported for Wild‐ID. However, they also suggest the programme is an effective tool for quickly identifying individuals in large field datasets, especially if photograph backgrounds are removed beforehand and postanalysis visual verification is performed.     

Digging deeper into East African human Y chromosome lineages

The most significant and widely studied remodeling of the African genetic landscape is the Bantu expansion, which led to an almost total replacement of the previous populations from the sub-Saharan region. However, a poor knowledge exists about other population movements, namely, the Nilotic migration, which is a pastoralist dispersal that, contrary to the Bantu expansion, impacted only East African populations. Here, samples from a Ugandan Nilotic-speaking population were studied for 37 Y chromosome-specific SNPs, and the obtained data were compared with those already available for other sub-Saharan population groups. Although Uganda lies on the fringe of both Bantu and Nilotic expansions, a low admixture with Bantu populations was detected, with haplogroups carrying M13, M182 and M75 mutations prevailing in Nilotes together with a low frequency of the main Bantu haplogroups from clade E1b1a-M2. The results of a comparative analysis with data from other population groups allowed a deeper characterization of some lineages in our sample, clarifying some doubts about the origin of some particular Y-SNPs in different ethnic groups, such as M150, M112 and M75. Moreover, it was also possible to identify a new Y-SNP apparently specific to Nilotic groups, as well as the presence of particular haplogroups that characterize Nilotic populations. The detection of a new haplogroup B2a1b defined by G1, could be, therefore, important to differentiate Nilotes from other groups, helping to trace migration and admixture events that occurred in eastern Africa.     

Indian Siddis: African descendants with Indian admixture

The Siddis (Afro-Indians) are a tribal population whose members live in coastal Karnataka, Gujarat, and in some parts of Andhra Pradesh. Historical records indicate that the Portuguese brought the Siddis to India from Africa about 300-500 years ago; however, there is little information about their more precise ancestral origins. Here, we perform a genome-wide survey to understand the population history of the Siddis. Using hundreds of thousands of autosomal markers, we show that they have inherited ancestry from Africans, Indians, and possibly Europeans (Portuguese). Additionally, analyses of the uniparental (Y-chromosomal and mitochondrial DNA) markers indicate that the Siddis trace their ancestry to Bantu speakers from sub-Saharan Africa. We estimate that the admixture between the African ancestors of the Siddis and neighboring South Asian groups probably occurred in the past eight generations (～200 years ago), consistent with historical records.     

Mitochondrial DNA diversity in two ethnic groups in Southeastern Kenya: Perspectives from the northeastern periphery of the bantu expansion

The Bantu languages are widely distributed throughout sub‐Saharan Africa. Genetic research supports linguists and historians who argue that migration played an important role in the spread of this language family, but the genetic data also indicates a more complex process involving substantial gene flow with resident populations. In order to understand the Bantu expansion process in east Africa, mtDNA hypervariable region I variation in 352 individuals from the Taita and Mijikenda ethnic groups was analyzed, and we evaluated the interactions that took place between the Bantu‐ and non‐Bantu‐speaking populations in east Africa. The Taita and Mijikenda are Bantu‐speaking agropastoralists from southeastern Kenya, at least some of whose ancestors probably migrated into the area as part of Bantu migrations that began around 3,000 BCE. Our analyses indicate that they show some distinctive differences that reflect their unique cultural histories. The Taita are genetically more diverse than the Mijikenda with larger estimates of genetic diversity. The Taita cluster with other east African groups, having high frequencies of haplogroups from that region, while the Mijikenda have high frequencies of central African haplogroups and cluster more closely with central African Bantu‐speaking groups. The non‐Bantu speakers who lived in southeastern Kenya before Bantu speaking groups arrived were at least partially incorporated into what are now Bantu‐speaking Taita groups. In contrast, gene flow from non‐Bantu speakers into the Mijikenda was more limited. These results suggest a more complex demographic history where the nature of Bantu and non‐Bantu interactions varied throughout the area. Am J Phys Anthropol 150:482–491, 2013. © 2013 Wiley Periodicals, Inc.     

Complex Patterns of Genomic Admixture within Southern Africa

Within-population genetic diversity is greatest within Africa, while between-population genetic diversity is directly proportional to geographic distance. The most divergent contemporary human populations include the click-speaking forager peoples of southern Africa, broadly defined as Khoesan. Both intra- (Bantu expansion) and inter-continental migration (European-driven colonization) have resulted in complex patterns of admixture between ancient geographically isolated Khoesan and more recently diverged populations. Using gender-specific analysis and almost 1 million autosomal markers, we determine the significance of estimated ancestral contributions that have shaped five contemporary southern African populations in a cohort of 103 individuals. Limited by lack of available data for homogenous Khoesan representation, we identify the Ju/''hoan (n = 19) as a distinct early diverging human lineage with little to no significant non-Khoesan contribution. In contrast to the Ju/''hoan, we identify ancient signatures of Khoesan and Bantu unions resulting in significant Khoesan- and Bantu-derived contributions to the Southern Bantu amaXhosa (n = 15) and Khoesan !Xun (n = 14), respectively. Our data further suggests that contemporary !Xun represent distinct Khoesan prehistories. Khoesan assimilation with European settlement at the most southern tip of Africa resulted in significant ancestral Khoesan contributions to the Coloured (n = 25) and Baster (n = 30) populations. The latter populations were further impacted by 170 years of East Indian slave trade and intra-continental migrations resulting in a complex pattern of genetic variation (admixture). The populations of southern Africa provide a unique opportunity to investigate the genomic variability from some of the oldest human lineages to the implications of complex admixture patterns including ancient and recently diverged human lineages.     

Y chromosomes traveling south: the cohen modal haplotype and the origins of the Lemba--the "Black Jews of Southern Africa"

The Lemba are a traditionally endogamous group speaking a variety of Bantu languages who live in a number of locations in southern Africa. They claim descent from Jews who came to Africa from "Sena." "Sena" is variously identified by them as Sanaa in Yemen, Judea, Egypt, or Ethiopia. A previous study using Y-chromosome markers suggested both a Bantu and a Semitic contribution to the Lemba gene pool, a suggestion that is not inconsistent with Lemba oral tradition. To provide a more detailed picture of the Lemba paternal genetic heritage, we analyzed 399 Y chromosomes for six microsatellites and six biallelic markers in six populations (Lemba, Bantu, Yemeni-Hadramaut, Yemeni-Sena, Sephardic Jews, and Ashkenazic Jews). The high resolution afforded by the markers shows that Lemba Y chromosomes are clearly divided into Semitic and Bantu clades. Interestingly, one of the Lemba clans carries, at a very high frequency, a particular Y-chromosome type termed the "Cohen modal haplotype," which is known to be characteristic of the paternally inherited Jewish priesthood and is thought, more generally, to be a potential signature haplotype of Judaic origin. The Bantu Y-chromosome samples are predominantly (>80%) YAP+ and include a modal haplotype at high frequency. Assuming a rapid expansion of the eastern Bantu, we used variation in microsatellite alleles in YAP+ sY81-G Bantu Y chromosomes to calculate a rough date, 3,000-5,000 years before the present, for the start of their expansion.