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Objectives: In genetic admixture processes, source groups for an admixed population possess distinct patterns of genotype and phenotype at the onset of admixture. Particularly in the context of recent and ongoing admixture, such differences are sometimes taken to serve as markers of ancestry for individuals-that is, phenotypes initially associated with the ancestral background in one source population are assumed to continue to reflect ancestry in that population. Such phenotypes might possess ongoing significance in social categorizations of individuals, owing in part to perceived continuing correlations with ancestry. However, genotypes or phenotypes initially associated with ancestry in one specific source population have been seen to decouple from overall admixture levels, so that they no longer serve as proxies for genetic ancestry. Here, we aim to develop an understanding of the joint dynamics of admixture levels and phenotype distributions in an admixed population., Methods: We devise a mechanistic model, consisting of an admixture model, a quantitative trait model, and a mating model. We analyze the behavior of the mechanistic model in relation to the model parameters., Results: We find that it is possible for the decoupling of genetic ancestry and phenotype to proceed quickly, and that it occurs faster if the phenotype is driven by fewer loci. Positive assortative mating attenuates the process of dissociation relative to a scenario in which mating is random with respect to genetic admixture and with respect to phenotype., Conclusions: The mechanistic framework suggests that in an admixed population, a trait that initially differed between source populations might serve as a reliable proxy for ancestry for only a short time, especially if the trait is determined by few loci. It follows that a social categorization based on such a trait is increasingly uninformative about genetic ancestry and about other traits that differed between source populations at the onset of admixture., (© 2021 Wiley Periodicals LLC.)

Objectives: While genetic studies have documented variation in admixture proportions in contemporary African Americans across the US, relatively little is known about the socio-historical roots of this variation. Our goal in this study is to use dental morphology to explore the socio-historical correlates of admixture, localized gene flow, and drift in African Americans., Methods: Our data are ordinally-graded dental morphological traits scored in 196 Africans, 335 Europeans and European Americans, 291 pre-Spanish-contact Native Americans, and 722 African Americans. The African American data derived from contemporary and historic samples. We eliminated from analysis individuals and traits with greater than 20% missing data. We summarized the major axes of trait variation using principal component analysis (PCA), estimated biological distance, constructed multidimensional scaling (MDS) plots of the distances, and measured the correlation between geographic and biological distance., Results: In the PCA, African American groups clustered between Africans and Europeans on PC 1, reflecting admixture between the groups. PC 2 separated African American samples, possibly reflecting movement, isolation, and drift. MDS analyses confirmed the existence of sizable biological distances between African American samples, especially between contemporary and past African American samples. We found no relationship between biological and geographic distances., Discussion: We demonstrate that admixture and drift can be inferred from multi-variable analyses of patterns of dental morphology in admixed populations. Localized gene flow has not affected patterns of trait variation in African Americans, but long-range movement, isolation, and drift have. We connect patterns of dental trait variation to efforts to flee oppression during the Great Migration, and the repeal of anti-miscegenation laws., (© 2021 Wiley Periodicals LLC.)

Objective: To analyze the genetic origin, relationships, structure, and admixture in Mayan Native American groups from Guatemala and Mexico based on 15 autosomal short tandem repeats (STRs) loci commonly used in human identification (HID)., Methods: We genotyped 513 unrelated Mayan samples from Guatemala based on 15 STR loci (AmpFlSTR® Identifiler kit). Moreover, we included 4408 genotypes previously reported, as following: Mayas from Guatemala and Mexico (n = 1666) and from Latin American, European, and African (n = 2742) populations. Forensic parameters, genetic distances, admixture, and population structure were assessed., Results: Forensic parameters of the 15 STRs in different Mayan groups from Guatemala were reported. Low (Fst = 0.78%; p = 0.000) and non-significant differentiation (Fst = 1.8%; p = 0.108) were observed in Mayas from Guatemala and Mexico, respectively. The relative homogeneity observed among Mayan groups supported theories of extensive pre-Columbian gene flow and trade throughout the Mayan Empire. The distribution of the three Native American ancestries among these Mayan groups did not support the presumable Guatemalan origin of Tojolabal and Lacandon people (South, Mexico). The nonsignificant differentiation between Ladinos and Mayas suggests a relative panmixia in Guatemala. Mestizos from southeastern Mexico and Guatemala constitute a core of Native American ancestry in Latin America related to the Mayan Empire in Central America., Conclusions: The higher European admixture and homogeneity in Mexican Mayas of the Yucatan Peninsula suggest more intensive post-Columbian gene flow in this region than in Guatemalan Mayas., (© 2021 Wiley Periodicals LLC.)

Objectives: Modern humans are thought to have interbred with Neanderthals in the Near East soon after modern humans dispersed out of Africa. This introgression event likely took place in either the Levant or southern Arabia depending on the dispersal route out of Africa that was followed. In this study, we compare Neanderthal introgression in contemporary Levantine and southern Arabian populations to investigate Neanderthal introgression and to study Near Eastern population history., Materials and Methods: We analyzed genotyping data on >400,000 autosomal SNPs from seven Levantine and five southern Arabian populations and compared these data to those from populations from around the world including Neanderthal and Denisovan genomes. We used f 4 and D statistics to estimate and compare levels of Neanderthal introgression between Levantine, southern Arabian, and comparative global populations. We also identified 1,581 putative Neanderthal-introgressed SNPs within our dataset and analyzed their allele frequencies as a means to compare introgression patterns in Levantine and southern Arabian genomes., Results: We find that Levantine and southern Arabian populations have similar levels of Neanderthal introgression to each other but lower levels than other non-Africans. Furthermore, we find that introgressed SNPs have very similar allele frequencies in the Levant and southern Arabia, which indicates that Neanderthal introgression is similarly distributed in Levantine and southern Arabian genomes., Discussion: We infer that the ancestors of contemporary Levantine and southern Arabian populations received Neanderthal introgression prior to separating from each other and that there has been extensive gene flow between these populations., (© 2019 Wiley Periodicals, Inc.)

Objectives: The Hui people are the adherents of Muslim faith and distributing throughout China. There are two contrasting hypotheses about the origin and diversification of the Hui people, namely, the demic diffusion involving the mass movement of people or simple cultural diffusion., Materials and Methods: We collected 621 unrelated male individuals from 23 Hui populations all over China. We comprehensively genotyped more than 100 informative Y-chromosomal single nucleotide polymorphisms and 17 Y-chromosomal short tandem repeats (STRs) on those samples., Results: Co-analyzed with published worldwide populations, our results suggest the origin of Hui people has involved massive assimilation of indigenous East Asians with about 70% in total of the paternal ancestry could be traced back to East Asia and the left 30% to various regions in West Eurasia., Discussion: The genetic structure of the extant Hui populations was primarily shaped by the indigenous East Asian populations as they contribute the majority part of the paternal lineages of Hui people. The West Eurasian admixture was probably a sex-biased male-driven process since we have not found such a high proportion of West Eurasian gene flow on autosomal STRs and maternal mtDNA., (© 2019 Wiley Periodicals, Inc.)

Objectives: The Sahel is a semi-arid zone stretching from the Atlantic Ocean in the west to the Red Sea in the east and from the Sahara in the north to the Sudanian Savanna in the south. Here, we investigated the genetic history of the spread of Northern African ancestry common among Berbers, the Y DNA haplogroup R1b-V88, and Chadic languages throughout the Sahel, with a focus on Chad., Materials and Methods: We integrated and analyzed genotype data from 751 individuals from Chad, Burkina Faso, Mali, South Sudan, and Sudan in the context of a global reference panel of 5,966 individuals., Results: We found that genetic diversity in Chad was broadly divided by a north-south axis. The core ancestry of Southern Chadians was Central African, most closely related to Pygmies. Southern Chadians then experienced four waves of gene flow over the last 3,000 years from West-Central Africans, Eastern Africans, West-Central Africans again, and then Arabians. In contrast, Northern Chadians did not share Central African ancestry and were not influenced by the first wave of West-Central Africans but were influenced by Northern African ancestry., Discussion: We found that Y DNA haplogroup R1b entered the Chadian gene pool during Baggarization. Baggara Arabs spoke Arabic, not Chadic, implying that people carrying R1b-V88 were not responsible for the spread of Chadic languages, which may have spread approximately 3,700 years ago. We found no evidence for migration of Near Eastern farmers or any ancient episodes involving Eurasian backflow., (Published 2018. This article is a U.S. Government work and is in the public domain in the USA.)

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., (© 2018 Wiley Periodicals, Inc.)

Objectives: The Jing people are a recognized ethnic group in Guangxi, southwest China, who are the immigrants from Vietnam during the 16th century. They speak Vietnamese but with lots of language borrowings from Cantonese, Zhuang, and Mandarin. However, it's unclear if there is large-scale gene flow from surrounding populations into Jing people during their language change due to the very limited genetic information of this population., Materials and Methods: We collected blood samples from 37 Jing and 3 Han Chinese individuals from Wanwei, Shanxin, and Wutou islands in Guangxi and genotyped about 600,000 genome-wide single nucleotide polymorphisms (SNPs). We used Principal Component Analysis (PCA), ADMIXTURE analysis, f statistics, qpWave and qpAdm to infer the population genetic structure and admixture., Results: Our data revealed that the Jing people are genetically similar to the populations in southwest China and mainland Southeast Asia. But compared with Vietnamese, they show significant evidence of gene flow from surrounding East Asians. The admixture proportion is estimated to be around 35-42% in different Jing groups using southern Han Chinese as a proxy. The majority of the paternal lineages of Jing people are most likely from surrounding East Asians., Discussion: We conclude that the formation and language change of present-day Jing people have involved genetic assimilation of surrounding East Asian populations. The language borrowing, in this case, is not only a cultural phenomenon but has involved demic diffusion., (© 2018 Wiley Periodicals, Inc.)

Objectives: African American populations in the U.S. formed primarily by mating between Africans and Europeans over the last 500 years. To date, studies of admixture have focused on either a one-time admixture event or continuous input into the African American population from Europeans only. Our goal is to gain a better understanding of the admixture process by examining models that take into account (a) assortative mating by ancestry in the African American population, (b) continuous input from both Europeans and Africans, and (c) historically informed variation in the rate of African migration over time., Materials and Methods: We used a model-based clustering method to generate distributions of African ancestry in three samples comprised of 147 African Americans from two published sources. We used a log-likelihood method to examine the fit of four models to these distributions and used a log-likelihood ratio test to compare the relative fit of each model., Results: The mean ancestry estimates for our datasets of 77% African/23% European to 83% African/17% European ancestry are consistent with previous studies. We find admixture models that incorporate continuous gene flow from Europeans fit significantly better than one-time event models, and that a model involving continuous gene flow from Africans and Europeans fits better than one with continuous gene flow from Europeans only for two samples. Importantly, models that involve continuous input from Africans necessitate a higher level of gene flow from Europeans than previously reported., Discussion: We demonstrate that models that take into account information about the rate of African migration over the past 500 years fit observed patterns of African ancestry better than alternative models. Our approach will enrich our understanding of the admixture process in extant and past populations., (© 2017 Wiley Periodicals, Inc.)

Objectives: The Tibetan-Yi Corridor located on the eastern edge of Tibetan Plateau is suggested to be the key region for the origin and diversification of Tibeto-Burman speaking populations and the main route of the peopling of the Plateau. However, the genetic history of the populations in the Corridor is far from clear due to limited sampling in the northern part of the Corridor., Materials and Methods: We collected blood samples from 10 Tibetan and 10 Han Chinese individuals from Gansu province and genotyped about 600,000 genome-wide single nucleotide polymorphisms (SNPs)., Results: Our data revealed that the populations in the Corridor are all admixed on a genetic cline of deriving ancestry from Tibetans on the Plateau and surrounding lowland East Asians. The Tibetan and Han Chinese groups in the north of the Plateau show significant evidence of low-level West Eurasian admixture that could be probably traced back to 600∼900 years ago., Discussion: We conclude that there have been huge population migrations from surrounding lowland onto the Tibetan Plateau via the Tibetan-Yi Corridor since the initial formation of Tibetans probably in Neolithic Time, which leads to the current genetic structure of Tibeto-Burman speaking populations., (© 2017 Wiley Periodicals, Inc.)

Objectives: European ancestry in many populations in Latin America at autosomal loci is often higher than that from X-linked loci indicating more European male ancestry and more Amerindian female ancestry. Generally, this has been attributed to more European male gene flow but could also result from an advantage to European mating or reproductive success., Methods: Population genetic models were developed to investigate the dynamics of gene flow and mating or reproductive success. Using estimates of autosomal and X-chromosome European ancestry, the amount of male gene flow or mating or reproductive advantage for Europeans, or those with European ancestry, was estimated., Results: In a population from Antioquia, Colombia with an estimated 79% European autosomal ancestry and an estimated 69% European X-chromosome ancestry, about 15% male gene flow from Europe or about 20% mating or reproductive advantage of Europeans over Amerindians resulted in these levels of European ancestry in the contemporary population. Combinations of gene flow and mating advantage were nearly additive in their impact., Conclusions: Gene flow, mating advantage, or a combination of both factors, are consistent with observed levels of European ancestry in a Latin American population. This approach provides a general methodology to determine the levels of gene flow and mating differences that can explain the observed contemporary differences in ancestry from autosomes and X-chromosomes., (© 2017 Wiley Periodicals, Inc.)

Objectives: The Endangered collared brown lemur (Eulemur collaris) is the largest primate living in the littoral forest of southeastern Madagascar, a top priority habitat for biodiversity conservation on the island. Because this lemur is a key seed-disperser, an evaluation of the structure and connectivity of the populations surviving in the forest fragments is urgently needed to guide conservation plans., Materials and Methods: Genetic variability at autosomal microsatellites and mitochondrial DNA was investigated in a total of 49 collared brown lemurs sampled by non-invasive methods in three littoral forest fragments and in the nearby lowland humid forest., Results: The overall genetic diversity of E. collaris in the southeastern coastal region of Madagascar was lower than in other populations, as well as in other lemur species. The population appears highly structured, with less variable and more inbred groups inhabiting the littoral forest fragments compared to the inland area. Major barriers to gene flow were identified isolating littoral forest fragments from each other and from the inland lowland humid forest., Discussion: Medium to long-term drift and scarce gene flow is the scenario that best explains the current genetic distribution. Habitat discontinuities such as rivers and grassland between forest fragments played a major role in structuring the population. A common history of size contraction is pointed out by several genetic estimators, indicating a possible ecological crisis triggered around 1,300 years ago. The adoption of strategies aimed at facilitating gene flow and population growth appears crucial to delay further loss of genetic diversity., (© 2017 Wiley Periodicals, Inc.)

Objectives: Studies of the apportionment of human genetic diversity have found that local populations harbor nearly as much diversity as the species as a whole. These studies have been a valuable cornerstone in rejecting race as a biological framework in anthropology. The current study presents new analyses that use updated statistical methods based on bifurcating trees to assess the structure of human genetic diversity and its implications for the existence of canonical biological races., Materials and Methods: We examine patterns of both goodness-of-fit and lack-of-fit of two bifurcating trees to patterns of diversity determined from autosomal short tandem repeat genotypes in 1,037 people representing 52 populations with worldwide distribution., Results: From goodness-of-fit, we infer a root for the tree within Africa, and we recapitulate a pattern of decreasing genetic diversity with increasing geographic distance from Africa. From lack-of-fit, we present tentative evidence for admixture events with archaic hominins. We do not find evidence that long-range migration or local gene flow have contributed appreciably to the lack of fit at a global scale., Conclusion: This is the first study to find a root for a tree of human populations without comparison to a nonhuman out-group, and it is one of the first studies to identify a signature of admixture with archaic hominins without reference to ancient DNA. Our findings complement previous studies of the apportionment of human diversity and provide a more solid evolutionary foundation for the rejection of biological race. Am J Phys Anthropol 160:561-569, 2016. © 2015 Wiley Periodicals, Inc., (© 2015 Wiley Periodicals, Inc.)

Objective: To analyze the origin, structure, relationships, and recent admixture in Mexican Native groups based on 15 STRs commonly used in human identification., Methods: We analyzed 39 Mexican Native population samples using STR databases based on the AmpFlSTR® Identifiler kit (n = 3,135), including Mexican-Mestizos (admixed), European and African populations, as reference., Results: Based upon effective population size (Ne) differences, Native groups were clustered into three regions: i) Center-Southeast groups, characterized by larger Ne, migration rate (Nm), genetic diversity (He), and relative homogeneity principally in the Yucatan Peninsula; ii) Isolated southern groups from Chiapas and Oaxaca, characterized by lower Ne, Nm, and He (i.e. higher isolation and genetic differentiation); iii) North-Northwest groups, which are similar to the previous group but are characterized by generating the widest gene flow barrier in the Pre-Hispanic Mexican territory, and currently by elevated admixture in some northern Native groups. Despite the relative congruence between genetic relationships with cultural, linguistic, geographic criteria, these factors do not explain the present-day population structure of Native groups, excepting in those linguistically related to the Mayan that show higher homogeneity. The Isolation by distance model was demonstrated at long distances (>1,500 km), whereas geographic isolation stands as a determining factor to avoid both non-indigenous admixture and bottleneck processes., Conclusions: Different dynamics of gene flow and drift were observed among Mexican Native groups, highlighting the geographic barriers (mountains, canyons and jungle regions) as the main factor differentiating Pre-Hispanic populations, and eventually helping to avoid Post-European contact admixture and population bottleneck. Am J Phys Anthropol 160:298-316, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Objectives: The number of distinct human migrations into the Aleutian Islands during the Holocene has been a recurrent debate in the anthropological literature. Stemming from Hrdlička's sorting of the prehistoric remains into two distinct populations based on archaeological context and cranial measurements, the human occupation of the Aleutian Islands has long been thought to be the consequence of two distinct human migrations, a Paleo-Aleut migration that provided the initial settlement of the islands, and a Neo-Aleut migration that replaced the original settlers around 1000 BP. This study examines the relationship of the Aleut cranial assemblages in the context of greater Alaskan population variability to assess the evidence for a substantial migration into the Aleutian Islands during the late Holocene., Materials and Methods: A battery of 29 cranial measurements that quantify global cranial shape were analyzed using Euclidean morphometric methods and quantitative genetic permutation methods to examine the plausibility for two distinct Aleut occupations ("Paleo-Aleut" and "Neo-Aleut"), the latter of which is held to share closer phenetic affinities to mainland Alaskan populations than the former. The Aleut skeletal assemblages were arranged according to temporal association, geographic location, and cranial typology, and analyzed within a comparative framework of mainland Alaskan samples using principal coordinates, biological distance and random skewers permutation methods., Results: Regardless of how the Aleut assemblages are divided, they show greater similarity to each other than to any of the mainland Alaskan assemblages. These findings are consistent across the methodological approaches., Discussion: The results obtained in this study provide no support for a cranial morphology-based subdivision of the Aleuts into two distinct samples, Hence, there is no evidence for a substantial population migration of so-called Neo-Aleuts, nor for a population replacement event of an extant Paleo-Aleut population by a mainland-affiliated Neo-Aleuts population at or after 1000 BP., (© 2016 Wiley Periodicals, Inc.)

High mtDNA variation in Southeastern Europe (SEE) is a reflection of the turbulent and complex demographic history of this area, influenced by gene flow from various parts of Eurasia and a long history of intermixing. Our results of 1035 samples (488 from Croatia, 239 from Bosnia and 130 from Herzegovina, reported earlier, and 97 Slovenians and 81 individuals from Žumberak, reported here for the first time) show that the SEE maternal genetic diversity fits within a broader European maternal genetic landscape. The study also shows that the population of Žumberak, located in the continental part of Croatia, developed some unique mtDNA haplotypes and elevated haplogroup frequencies due to distinctive demographic history and can be considered a moderate genetic isolate. We also report seven samples from the Bosnian population and one Herzegovinian sample designated as X2* individuals that could not be assigned to any of its sublineages (X2a'o) according to the existing X2 phylogeny. In an attempt to clarify the phylogeny of our X2 samples, their mitochondrial DNA has been completely sequenced. We suppose that these lineages are signs of local microdifferentiation processes that occurred in the recent demographic past in this area and could possibly be marked as SEE-specific X2 sublineages., (© 2014 John Wiley & Sons Ltd/University College London.)

In this study, we explore the geographic and temporal distribution of a unique variant of the O blood group allele called O1v(G542A) , which has been shown to be shared among Native Americans but is rare in other populations. O1v(G542A) was previously reported in Native American populations in Mesoamerica and South America, and has been proposed as an ancestry informative marker. We investigated whether this allele is also found in the Tlingit and Haida, two contemporary indigenous populations from Alaska, and a pre-Columbian population from California. If O1v(G542A) is present in Na-Dene speakers (i.e., Tlingits), it would indicate that Na-Dene speaking groups share close ancestry with other Native American groups and support a Beringian origin of the allele, consistent with the Beringian Incubation Model. If O1v(G542A) is found in pre-Columbian populations, it would further support a Beringian origin of the allele, rather than a more recent introduction of the allele into the Americas via gene flow from one or more populations which have admixed with Native Americans over the past five centuries. We identified this allele in one Na-Dene population at a frequency of 0.11, and one ancient California population at a frequency of 0.20. Our results support a Beringian origin of O1v(G542A) , which is distributed today among all Native American groups that have been genotyped in appreciable numbers at this locus. This result is consistent with the hypothesis that Na-Dene and other Native American populations primarily derive their ancestry from a single source population., (Copyright © 2013 Wiley Periodicals, Inc.)

The male dispersal patterns of western lowland gorillas (WLGs, Gorilla gorilla gorilla) are not well understood. To determine whether most silverbacks stay close to their relatives, we analyzed autosomal and Y-chromosomal microsatellites (STRs) in wild WLGs at Moukalaba, Gabon. We obtained STR genotypes for 38 individuals, including eight silverbacks and 12 adult females in an approximately 40 km(2) area. Among them, 20 individuals were members of one identified group (Group Gentil; GG), including one silverback and six adult females. The silverback sired all 13 of the offspring in GG and no Y-STR polymorphism within GG was found, as expected in a one-male group structure. Over all silverbacks sampled, Y-STR diversity was high considering the limited sampling area, and silverbacks with similar Y-STR haplotypes were not always located in nearby areas. Although the misclassification rate of kinship estimates in this study was not negligible, there were no kin dyads among all silverbacks sampled. These results suggest that silverbacks born in the same group do not stay close to each other after maturation. The Y-STR diversity in this study was similar to that of a previous study conducted in an area that was approximately 150 times larger than our study area. Similarity of WLG Y-STR diversity between studies at different sampling scales suggests that male gene flow may not be geographically limited. These results suggest that WLG males normally disperse from their natal areas after maturation, at least, in Moukalaba., (Copyright © 2013 Wiley Periodicals, Inc.)

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., (Copyright © 2013 Wiley Periodicals, Inc.)

Western black-and-white colobus and Temmink's red colobus are two forest-dependent African primates with similar ecological requirements, often found in sympatry. Their most striking difference lies in their social system: black-and-white colobus live in small groups with mainly male-mediated dispersal but where females can also disperse, whereas red colobus live in larger groups with males described as philopatric. To investigate whether genetic evidence supports the reported patterns of dispersal based on observational data, we examined eight black-and-white and six red colobus social groups from Cantanhez National Park, Guinea-Bissau. Microsatellite markers revealed a lack of sex-biased dispersal for black-and-white colobus. Gene flow, mainly mediated by females, better explained the genetic patterns found in red colobus, with some evidence for less extensive male dispersal. In contrast to the microsatellite data, low mitochondrial diversity for the black-and-white colobus suggests that historical and/or long-range male-mediated gene flow might have been favored. In red colobus, the co-existence of three divergent mitochondrial haplogroups suggests that the Cantanhez population contains a secondary contact zone between divergent lineages that evolved in allopatry. Female-biased dispersal in this species may be a major factor contributing to the colonization by such differentiated mitochondrial lineages in the region. Overall, we find evidence for a spatio-temporal change in the dispersal patterns of the colobus monkeys of Cantanhez, with mitochondrial DNA indicating dispersal by mainly a single sex and microsatellite data suggesting that recently both sexes appear to be dispersing within the population., (Copyright © 2013 Wiley Periodicals, Inc.)

The purpose of this article is to examine the patterns of evolutionary relationships between human populations from the later Late Holocene (1,500-100 years BP) of southern South America on the basis of dental morphometric data. We tested the hypotheses that the variation observed in this region would be explained by the existence of populations with different phylogenetic origin or differential action of gene flow and genetic drift. In this study, we analyzed permanent teeth from 17 samples of male and female adult individuals from throughout southern South America. We measured mesiodistal and buccolingual diameters at the base of the crown, along the cement-enamel junction. The results of multiple regression analysis and a mantel correlogram indicate the existence of spatial structure in dental shape variation, as the D(2) Mahalanobis distance between samples increases with increasing geographical distance between them. In addition, the correlation test results show a trend toward reduction of the internal variation of samples with increasing latitude. The detected pattern of dental variation agrees with the one expected as an outcome of founder serial effects related to an expansion of range during the initial occupation of southern South America.

The Yakuts are a Turkic-speaking population from northeastern Siberia who are believed to have originated from ancient Turkic populations in South Siberia, based on archaeological and ethnohistorical evidence. In order to better understand Yakut origins, we modeled 25 demographic scenarios and tested by coalescent simulation whether any are consistent with the patterns of mtDNA diversity observed in present-day Yakuts. The models consist of either two simulated demes that represent Yakuts and a South Siberian ancestral population, or three demes that also include a regional Northeast Siberian population that served as a source of local gene flow into the Yakut deme. The model that produced the best fit to the observed data defined a founder group with an effective female population size of only 150 individuals that migrated northwards approximately 1,000 years BP and who experienced significant admixture with neighboring populations in Northeastern Siberia. These simulation results indicate a pronounced founder effect that was primarily kin-structured and reconcile reported discrepancies between Yakut mtDNA and Y chromosome diversity levels.

In a previous study, Kaestle and Smith [Am J Phys Anthropol 115 (2001) 1-12] supported a recent (A.D. 1000) Numic expansion into the Great Basin region based on a molecular and statistical analysis of mitochondrial DNA (mtDNA) of ancient and modern native inhabitants of the region. Their statistical methodology could not rule out the possibility that observed differences in haplogroup frequencies are instead the result of long-term microevolutionary change within a single population. To distinguish more effectively between a Numic expansion versus population continuity, we employed a novel computer simulation approach that incorporates microevolutionary factors likely to affect human population genetic variation. We test whether the observed differences in haplogroup frequencies between ancient and modern Great Basin groups could have been produced solely via in situ microevolutionary change. Our results indicate that for reasonable demographic conditions, the observed genetic differences between the observed samples are consistent with population continuity if gene flow among prehistoric Great Basin local groups was less than 1% of local group size per generation. Our analysis also supports a recent population expansion if gene flow between neighboring groups exceeded 8% of local group size per generation. The simulations demonstrate that relatively low gene flow levels and random genetic drift can produce the observed degree of genetic differences between population samples. Although this study focuses on the Numic expansion, this simulation approach can be applied to any geographic region for which genetic data have been collected to address similar questions of population relationships over time., ((c) 2007 Wiley-Liss, Inc.)

Blood samples were collected in Algeria from 4,444 army recruits and tested for 10 genetic polymorphic systems. These samples were collected from territorial Wilayas (administrative units of Algeria) from which the young soldiers had originated. Based on similar geography and economic and political history, these Wilayas were clustered into 10 regions. These regions, not part of the governmental administrative units, were characterized by allelic frequencies, and analyzed using R-matrix principal components, Wright's F(ST), spatial autocorrelation, and Mantel tests. Hierarchical relationships between the culturally defined regions were examined using two different analytical methods of phylogenetic tree constructions: neighbor-joining, and unweighted pair group average arithmetic (UPGMA). These results indicated the predominance of genetic homogeneity due to the gene flow between regions, but with some migration emanating from sub-Saharan Africa and Mediterranean Europe. Wright's F(ST) value of 0.0063, based on 16 alleles, suggested a relatively small genetic microdifferentiation of the regions. In Algeria, gene flow apparently swamped most of the effects of stochastic processes and disrupted the relationship between geography and genetics, as characterized by the isolation-by-distance model. Some genetic differences and similarities were observed between regions or clusters of regions. The resulting genetic structure of the Algerian populations is best explained by a combination of gene flow, ecology, and history.

In this work, seven multiallelic short-tandem repeat (STR) loci from the nonrecombining region of the human Y-chromosome (DYS19, DYS389 I, DYS389 II, DYS390, DYS391, DYS392, and DYS393) were typed in a sample of residents in the Basque Country (RBAS). In all, 40 different Y-STR haplotypic combinations were identified, resulting in a value of haplotypic diversity of 0.979. Y-STR data compiled from previous works were used for studying Y-chromosome diversity in the Iberian Peninsula and for assessing the effects of migratory movements on the genetic background of the population living currently in territories traditionally occupied by native (autochthonous) Basques. An analysis of the spatial distribution of allelic frequencies of the Y-STRs revealed a geographic pattern characterized by variation gradients (frequency clines) oriented for the most part in the direction southwest-northeast. Accordingly, a neighbor-joining analysis showed a relative polarization between populations located in the northeast and center of the Iberian Peninsula, and the rest of the samples considered. The study sample (RBAS) occupied an intermediate position in the population tree between the autochthonous Basques (BASQ) and the remaining samples. Interestingly, the RBAS collection only showed genetic heterogeneity with that of native Basques (PhiST = 0.013, P < 0.05). Estimates of admixture proportions in the gene pool of RBAS indicated a high level of hybridization with Basque (56%) and non-Basque (44%) genes, which could explain the genetic differentiation observed between BASQ and RBAS.