Contrasting maternal and paternal genetic histories among five ethnic groups from Khyber Pakhtunkhwa, Pakistan.

Northwest Pakistan has served as a point of entry to South Asia for different populations since ancient times. However, relatively little is known about the population genetic history of the people residing within this region. To better understand human dispersal in the region within the broader history of the subcontinent, we analyzed mtDNA diversity in 659 and Y-chromosome diversity in 678 individuals, respectively, from five ethnic groups (Gujars, Jadoons, Syeds, Tanolis and Yousafzais), from Swabi and Buner Districts, Khyber Pakhtunkhwa Province, Pakistan. The mtDNAs of all individuals were subject to control region sequencing and SNP genotyping, while Y-chromosomes were analyzed using 54 SNPs and 19 STR loci. The majority of the mtDNAs belonged to West Eurasian haplogroups, with the rest belonging to either South or East Asian lineages. Four of the five Pakistani populations (Gujars, Jadoons, Syeds, Yousafzais) possessed strong maternal genetic affinities with other Pakistani and Central Asian populations, whereas one (Tanolis) did not. Four haplogroups (R1a, R1b, O3, L) among the 11 Y-chromosome lineages observed among these five ethnic groups contributed substantially to their paternal genetic makeup. Gujars, Syeds and Yousafzais showed strong paternal genetic affinities with other Pakistani and Central Asian populations, whereas Jadoons and Tanolis had close affinities with Turkmen populations from Central Asia and ethnic groups from northeast India. We evaluate these genetic data in the context of historical and archeological evidence to test different hypotheses concerning their origins and biological relationships.

An initial investigation of dental morphology variation among three southern Naga ethnic groups of Northeast India.

OBJECTIVES: This study examines dental morphology trait prevalence among three southern Naga groups and compares them to 10 ethnic groups from other regions of South Asia to accomplish two objectives: assess the biological relationship of these Tibeto-Burman-speakers to speakers of non-Tibeto-Burman languages in other South Asian regions, and determine which traits distinguish northeast Indians from other South Asians. METHODS: Dental morphology traits were scored with the Arizona State University Dental Anthropology System. Tooth-trait combinations were evaluated for significant inter-trait correlation and intra-trait correspondence within dental fields. Comparisons were based on simple trait prevalence and with Smith's MMD. Affinities based on the former were accomplished with correspondence analysis and principal components analysis. Affinities based on the latter were undertaken with neighbor-joining cluster analysis and multidimensional scaling. RESULTS: After elimination due to inter-trait correlations and uniform prevalence, biodistances based on the remaining 17 tooth-trait combinations identify significant differences between northeast Indians and other South Asian ethnic groups due to high frequencies of shoveling on the maxillary incisors and Cusp 6 on the mandibular molars coupled with low frequencies of Carabelli's trait and Cusp 5 on UM1 and UM2, respectively. CONCLUSIONS: Patterns of biodistances obtained from dental morphology are consilient with those obtained from DNA indicating statistically significant differences between northeast Indians from members of ethnic groups of other regions of South Asia. Researchers should explore the sex-specific patterns. Biodistances should not be limited to "key" teeth within dental fields, for in almost every case traits present on mesial and distal teeth yield non-redundant information.

Mitochondrial DNA diversity in the Khattak and Kheshgi of the Peshawar Valley, Pakistan.

The strategic location of Pakistan and its presence at the crossroads of Asia has resulted in it playing a central role in both prehistoric and historic human migratory events, thereby linking and facilitating contacts between the inhabitants of the Middle East, Central Asia, China and South Asia. Despite the importance of this region and its inhabitants for our understanding of modern human origins and population dispersals, the nature of mitochondrial DNA (mtDNA) variation among members of the myriad populations of this area has largely been unexplored. Here, we report mtDNA control region sequences in 58 individuals from the Khattak and the Kheshgi, two major Pakhtun tribes residing within the Peshawar Valley of northwestern Pakistan. The results reveal that these ethnic groups are genetically heterogeneous, having 55.7% West Eurasian, 33.9% South Asian and 10.2% East Asian haplogroups. The genetic diversity observed for the Kheshgi was somewhat higher than that of the Khattak. A multidimensional scaling plot based on haplogroup frequencies for the Khattak, Kheshgi and neighboring populations indicates that the Khattak have close affinities with Baluch, Uzbek and Kazak populations but are only distantly related to the Kheshgi and other Pakistani populations. By contrast, the Kheshgi cluster closely with other Pakhtun or Pathan populations of Pakistan, suggesting a possible common maternal gene pool shared amongst them. These mtDNA data allow us to begin reconstructing the origins of the Khattak and Kheshgi and describe their complex interactions with populations from the surrounding regions.

High Y-chromosomal Differentiation Among Ethnic Groups of Dir and Swat Districts, Pakistan.

The ethnic groups that inhabit the mountainous Dir and Swat districts of northern Pakistan are marked by high levels of cultural and phenotypic diversity. To obtain knowledge of the extent of genetic diversity in this region, we investigated Y-chromosomal diversity in five population samples representing the three main ethnic groups residing within these districts, including Gujars, Pashtuns and Kohistanis. A total of 27 Y-chromosomal short tandem repeats (Y-STRs) and 331 Y-chromosomal single nucleotide polymorphisms (Y-SNPs) were investigated. In the Y-STRs, we observed very high and significant levels of genetic differentiation in nine of the 10 pairwise between-group comparisons (RST 0.179-0.746), and the differences were mirrored in the Y-SNP haplogroup frequency distribution. No genetic differences were found between the two Pashtun subethnic groups Tarklanis and Yusafzais (RST = 0.000). Utmankhels, also considered Pashtuns culturally, were not closely related to any of the other population samples (RST 0.451-0.746). Thus, our findings provide examples of both associations and dissociations between cultural and genetic legacies. When analyzed within a larger continental-scale context, these five ethnic groups fall mostly outside the previously characterized Y-chromosomal gene pools of the Indo-Pakistani subcontinent. Male founder effects, coupled with culturally and topographically based constraints upon marriage and movement, are likely responsible for the high degree of genetic structure in this region.

The apportionment of tooth size and its implications in Australopithecus sediba versus other Plio-pleistocene and recent African hominins.

OBJECTIVES: Australopithecus sediba is characterized further by providing formerly unpublished and refined mesiodistal and buccolingual crown measurements in the MH1 and MH2 specimens. After size correction, these data were compared with those in other fossil and recent samples to facilitate additional insight into diachronic hominin affinities. MATERIALS AND METHODS: Six comparative samples consist of fossil species: A. africanus, A. afarensis, Homo habilis, Paranthropus robustus, P. boisei, and H. erectus. Others comprise H. sapiens and Pan troglodytes. Re-estimates of "actual" dimensions in damaged A. sediba teeth were effected through repeated measurements by independent observers. X-ray synchrotron microtomography allowed measurement of crowns obscured by matrix and noneruption. Tooth size apportionment analysis, an established technique for intraspecific comparisons, was then applied at this interspecific level to assess phenetic affinities using both within- and among-group data. RESULTS: Comparison of these highly heritable dimensions identified a general trend for smaller posterior relative to larger anterior teeth (not including canines), contra Paranthropus, that allies A. sediba with other australopiths and Homo; however, specific reductions and/or shape variation in the species' canines, third premolars, and anterior molars relative to the other teeth mirror the patterning characteristic of Homo. DISCUSSSION: Of all samples, including east African australopiths, A. sediba appears most like H. habilis, H. erectus and H. sapiens regarding how crown size is apportioned along the tooth rows. These findings parallel those in prior studies of dental and other skeletal data, including several that suggest A. sediba is a close relative of, if not ancestral to, Homo.

Horse-mounted invaders from the Russo-Kazakh steppe or agricultural colonists from western Central Asia? A craniometric investigation of the Bronze Age settlement of Xinjiang.

Numerous Bronze Age cemeteries in the oases surrounding the Täklamakan Desert of the Tarim Basin in the Xinjiang Uyghur Autonomous Region, western China, have yielded both mummified and skeletal human remains. A dearth of local antecedents, coupled with woolen textiles and the apparent Western physical appearance of the population, raised questions as to where these people came from. Two hypotheses have been offered by archaeologists to account for the origins of Bronze Age populations of the Tarim Basin. These are the "steppe hypothesis" and the "Bactrian oasis hypothesis." Eight craniometric variables from 25 Aeneolithic and Bronze Age samples, comprising 1,353 adults from the Tarim Basin, the Russo-Kazakh steppe, southern China, Central Asia, Iran, and the Indus Valley, are compared to test which, if either, of these hypotheses are supported by the pattern of phenetic affinities possessed by Bronze Age inhabitants of the Tarim Basin. Craniometric differences between samples are compared with Mahalanobis generalized distance (d2), and patterns of phenetic affinity are assessed with two types of cluster analysis (the weighted pair average linkage method and the neighbor-joining method), multidimensional scaling, and principal coordinates analysis. Results obtained by this analysis provide little support for either the steppe hypothesis or the Bactrian oasis hypothesis. Rather, the pattern of phenetic affinities manifested by Bronze Age inhabitants of the Tarim Basin suggests the presence of a population of unknown origin within the Tarim Basin during the early Bronze Age. After 1200 B.C., this population experienced significant gene flow from highland populations of the Pamirs and Ferghana Valley. These highland populations may include those who later became known as the Saka and who may have served as "middlemen" facilitating contacts between East (Tarim Basin, China) and West (Bactria, Uzbekistan) along what later became known as the Great Silk Road.