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We examined variation on the nonrecombining portion of the human Y chromosome to investigate human evolution during the last 200,000 years. The Y-specific polymorphic sites included the Y Alu insertional polymorphism or 'YAP' element (DYS287), the poly(A) tail associated with the YAP element, three point mutations in close association with the YAP insertion site, an A-G polymorphic transition (DYS271), and a tetranucleotide microsatellite (DYS19). Global variation at the five bi-allelic sites (DYS271, DYS287, and the three point mutations) gave rise to five 'YAP haplotypes' in 60 populations from Africa, Europe, Asia, Australasia, and the New World (n = 1500). Combining the multi-allelic variation at the microsatellite loci (poly(A) tail and DYS19) with the YAP haplotypes resulted in a total of 27 'combination haplotypes'. All five of the YAP haplotypes and 21 of the 27 combination haplotypes were found in African populations, which had greater haplotype diversity than did populations from other geographical locations. Only subsets of the five YAP haplotypes were found outside of Africa. Patterns of observed variation were compatible with a variety of hypotheses, including multiple human migrations and range expansions.

Human Y chromosome haplogroup J1-M267 is a common male lineage in West Asia. One high-frequency region-encompassing the Arabian Peninsula, southern Mesopotamia, and the southern Levant-resides ~ 2000 km away from the other one found in the Caucasus. The region between them, although has a lower frequency, nevertheless demonstrates high genetic diversity. Studies associate this haplogroup with the spread of farming from the Fertile Crescent to Europe, the spread of mobile pastoralism in the desert regions of the Arabian Peninsula, the history of the Jews, and the spread of Islam. Here, we study past human male demography in West Asia with 172 high-coverage whole Y chromosome sequences and 889 genotyped samples of haplogroup J1-M267. We show that this haplogroup evolved ~ 20,000 years ago somewhere in northwestern Iran, the Caucasus, the Armenian Highland, and northern Mesopotamia. The major branch-J1a1a1-P58-evolved during the early Holocene ~ 9500 years ago somewhere in the Arabian Peninsula, the Levant, and southern Mesopotamia. Haplogroup J1-M267 expanded during the Chalcolithic, the Bronze Age, and the Iron Age. Most probably, the spread of Afro-Asiatic languages, the spread of mobile pastoralism in the arid zones, or both of these events together explain the distribution of haplogroup J1-M267 we see today in the southern regions of West Asia.

Background: The peopling of Europe and the nature of the Neolithic agricultural migration as a primary issue in the modern human colonization of the globe is still widely debated. At present, much uncertainty is associated with the reconstruction of the routes of migration for the first farmers from the Near East. In this context, hospitable climatic conditions and the key geographic position of the Armenian Highland suggest that it may have served as a conduit for several waves of expansion of the first agriculturalists from the Near East to Europe and the North Caucasus., Results: Here, we assess Y-chromosomal distribution in six geographically distinct populations of Armenians that roughly represent the extent of historical Armenia. Using the general haplogroup structure and the specific lineages representing putative genetic markers of the Neolithic Revolution, haplogroups R1b1a2, J2, and G, we identify distinct patterns of genetic affinity between the populations of the Armenian Highland and the neighboring ones north and west from this area., Conclusions: Based on the results obtained, we suggest a new insight on the different routes and waves of Neolithic expansion of the first farmers through the Armenian Highland. We detected at least two principle migratory directions: (1) westward alongside the coastline of the Mediterranean Sea and (2) northward to the North Caucasus.

Hispanic/Latino populations possess a complex genetic structure that reflects recent admixture among and potentially ancient substructure within Native American, European, and West African source populations. Here, we quantify genome-wide patterns of SNP and haplotype variation among 100 individuals with ancestry from Ecuador, Colombia, Puerto Rico, and the Dominican Republic genotyped on the Illumina 610-Quad arrays and 112 Mexicans genotyped on Affymetrix 500K platform. Intersecting these data with previously collected high-density SNP data from 4,305 individuals, we use principal component analysis and clustering methods FRAPPE and STRUCTURE to investigate genome-wide patterns of African, European, and Native American population structure within and among Hispanic/Latino populations. Comparing autosomal, X and Y chromosome, and mtDNA variation, we find evidence of a significant sex bias in admixture proportions consistent with disproportionate contribution of European male and Native American female ancestry to present-day populations. We also find that patterns of linkage-disequilibria in admixed Hispanic/Latino populations are largely affected by the admixture dynamics of the populations, with faster decay of LD in populations of higher African ancestry. Finally, using the locus-specific ancestry inference method LAMP, we reconstruct fine-scale chromosomal patterns of admixture. We document moderate power to differentiate among potential subcontinental source populations within the Native American, European, and African segments of the admixed Hispanic/Latino genomes. Our results suggest future genome-wide association scans in Hispanic/Latino populations may require correction for local genomic ancestry at a subcontinental scale when associating differences in the genome with disease risk, progression, and drug efficacy, as well as for admixture mapping.

In this study, 231 Y chromosomes from 12 populations were typed for four diagnostic single nucleotide polymorphisms (SNPs) to determine haplogroup membership and 43 Y chromosomes from three of these populations were typed for eight short tandem repeats (STRs) to determine haplotypes. These data were combined with previously published data, amounting to 724 Y chromosomes from 26 populations in North America, and analyzed to investigate the geographic distribution of Y chromosomes among native North Americans and to test the Southern Athapaskan migration hypothesis. The results suggest that European admixture has significantly altered the distribution of Y chromosomes in North America and because of this caution should be taken when inferring prehistoric population events in North America using Y chromosome data alone. However, consistent with studies of other genetic systems, we are still able to identify close relationships among Y chromosomes in Athapaskans from the Subarctic and the Southwest, suggesting that a small number of proto-Apachean migrants from the Subarctic founded the Southwest Athapaskan populations., ((c) 2008 Wiley-Liss, Inc.)

Genetic variation on the non-recombining portion of the Y chromosome contains information about the ancestry of male lineages. Because of their low rate of mutation, single nucleotide polymorphisms (SNPs) are the markers of choice for unambiguously classifying Y chromosomes into related sets of lineages known as haplogroups, which tend to show geographic structure in many parts of the world. However, performing the large number of SNP genotyping tests needed to properly infer haplogroup status is expensive and time consuming. A novel alternative for assigning a sampled Y chromosome to a haplogroup is presented here. We show that by applying modern machine-learning algorithms we can infer with high accuracy the proper Y chromosome haplogroup of a sample by scoring a relatively small number of Y-linked short tandem repeats (STRs). Learning is based on a diverse ground-truth data set comprising pairs of SNP test results (haplogroup) and corresponding STR scores. We apply several independent machine-learning methods in tandem to learn formal classification functions. The result is an integrated high-throughput analysis system that automatically classifies large numbers of samples into haplogroups in a cost-effective and accurate manner.

A set of 61 Y chromosome single-nucleotide-polymorphisms (Y-SNPs) is typed in a sample of 2517 individuals from 38 populations to infer the geographic origins of Y chromosomes in the United States and to test for paternal admixture among African-, European-, Hispanic-, Asian-, and Native-Americans. All of the samples were previously typed with the 11 core U.S. Y chromosome short tandem repeats (Y-STRs) recommended by SWGDAM, which revealed high levels of among ethnic group variation and low levels of among-population-within-ethnic-group variation. Admixture estimates vary greatly among populations and ethnic groups. The frequencies of non-European (3.4%) and non-Asian (4.5%) Y chromosomes are generally low in European-American and Asian-American populations, respectively. The frequencies of European Y chromosomes in Native-American populations range widely (i.e., 7-89%) and follow a West to East gradient, whereas they are relatively consistent in African-American populations (26.4+/-8.9%) from different locations. The European (77.8+/-9.3%) and Native-American (13.7+/-7.4%) components of the Hispanic paternal gene pool are also relatively constant among geographic regions; however, the African contribution is much higher in the Northeast (10.5+/-6.4%) than in the Southwest (1.5+/-0.9%) or Midwest (0%). To test for the effects of inter-ethnic admixture on the structure of Y-STR diversity in the U.S., we perform subtraction analyses in which Y chromosomes inferred to be admixed by Y-SNP analysis are removed from the database and pairwise population differentiation tests are implemented on the remaining Y-STR haplotypes. Results show that low levels of heterogeneity previously observed between pairs of Hispanic-American populations disappear when African-derived chromosomes are removed from the analysis. This is not the case for an unusual sample of European-Americans from New York City when its African-derived chromosomes are removed, or for Native-American populations when European-derived chromosomes are removed. We infer that both inter-ethnic admixture and population structure in ancestral source populations may contribute to fine scale Y-STR heterogeneity within U.S. ethnic groups.

To investigate the paternal population history of populations in Northern Island Melanesia, 685 paternally unrelated males from 36 populations in this region and New Guinea were analyzed at 14 regionally informative binary markers and 7 short tandem repeat (STR) loci from the nonrecombining portion of the Y chromosome. Three newly defined binary markers (K6-P79, K7-P117, and M2-P87) aided in identifying considerable heterozygosity that would have otherwise gone undetected. Judging from their geographic distributions and network analyses of their associated STR profiles, 4 lineages appear to have developed in this region and to be of considerable age: K6-P79, K7-P117, M2-P87, and M2a-P22. The origins of K5-M230 and M-M4 are also confirmed as being located further west, probably in New Guinea. In the 25 adequately sampled populations, the number of different haplogroups ranged from 2 in the single most isolated group (the Aita of Bougainville), to 9, and measures of molecular diversity were generally not particularly low. The resulting pattern contradicts earlier findings that suggested far lower male-mediated diversity and gene exchange rates in the region. However, these earlier studies had not included the newly defined haplogroups. We could only identify a very weak signal of recent male Southeast Asian genetic influence (<10%), which was almost entirely restricted to Austronesian (Oceanic)-speaking groups. This contradicts earlier assumptions on the ancestral composition of these groups and requires a revision of hypotheses concerning the settlement of the islands of the central Pacific, which commenced from this region.

A DNA database consisting of the 11 Y chromosome short-tandem-repeat (Y-STR) recommended by the Scientific Working Group on DNA Analysis Methods is constructed for 2517 individuals from 38 populations in the United States. The population samples derive from five ethnic groups currently living in 10 states. A multidimensional scaling (MDS) plot places the populations into four discrete clusters (African Americans (AA), European Americans (EA), Hispanic Americans (HA), and Asian Americans (SA)) and one dispersed cluster of Native Americans. An analysis of molecular variance (AMOVA) indicates that a large proportion of the total genetic variance is partitioned among ethnic groups (24.8%), whereas only a small amount (1.5%) is found among-populations within ethnic groups. Separate AMOVA analyses within each ethnic group show that only the NA sample contains statistically significant among-population variation. Pair wise population differentiation tests do uncover heterogeneity among EA and among HA populations; however, this is due to only a single sample within each group. The analyses support the creation of AA, EA, HA, and Asian American databases in which samples from different geographic regions within the United States are pooled. We recommend that separate databases be constructed for different NA groups.

We identified and characterized 14 novel short-tandem-repeats (STRs) on the Y chromosome and typed them in two samples, a globally diverse panel of 73 cell lines, and 148 individuals from a European-American population. These Y-STRs include eight tetranucleotide repeats (DYS449, DYS453, DYS454, DYS455, DYS456, DYS458, DYS459, and DYS464), five pentanucleotide repeats (DYS446, DYS447, DYS450, DYS452, and DYS463), and one hexanucleotide repeat (DYS448). Sequence data were obtained to designate a repeat number nomenclature. The gene diversities of an additional 22 Y-STRs, including the most commonly used in forensic databases, were directly compared in the cell line DNAs. Six of the 10 most polymorphic markers include the newly identified Y-STRs. Furthermore, these novel Y-STRs greatly improved the resolution of paternal lineages, above the level obtained with commonly used Y-STRs, in the European-American population., (Copyright 2002 Elsevier Science Ireland Ltd.)

Phenotypic similarities between Australian Aboriginal People and some tribes of India were noted by T.H. Huxley during the voyage of the Rattlesnake (1846-1850). Anthropometric studies by Birdsell led to his suggestion that a migratory wave into Australia included populations with affinities to tribal Indians. Genetic evidence for an Indian contribution to the Australian gene pool is contradictory; most studies of autosomal markers have not supported this hypothesis (; and references therein). On the other hand, affinities between Australian Aboriginal People and southern Indians were suggested based on maternally inherited mitochondrial DNA. Here, we show additional DNA evidence in support of Huxley's hypothesis of an Indian-Australian connection using single-nucleotide polymorphisms (SNPs) and short tandem repeats (STRs) on the nonrecombining portion of the Y chromosome (NRY). Phylogenetic analyses of STR variation associated with a major Australian SNP lineage indicated tight clustering with southern Indian/Sri Lankan Y chromosomes. Estimates of the divergence time for these Indian and Australian chromosomes overlap with important changes in the archaeological and linguistic records in Australia. These results provide strong evidence for an influx of Y chromosomes from the Indian subcontinent to Australia that may have occurred during the Holocene.

Asia has served as a focal point for human migration during much of the Late Pleistocene and Holocene. Clarification of East Asia's role as a source and/or transit point for human dispersals requires that this region's own settlement history be understood. To this end, we examined variation at 52 polymorphic sites on the nonrecombining portion of the Y chromosome (NRY) in 1,383 unrelated males, representing 25 populations from southern East Asia (SEAS), northern East Asia (NEAS), and central Asia (CAS). The polymorphisms defined 45 global haplogroups, 28 of which were present in these three regions. Although heterozygosity levels were similar in all three regions, the average pairwise difference among haplogroups was noticeably smaller in SEAS. Multidimensional scaling analysis indicated a general separation of SEAS versus NEAS and CAS populations, and analysis of molecular variance produced very different values of Phi(ST) in NEAS and SEAS populations. In spatial autocorrelation analyses, the overall correlogram exhibited a clinal pattern; however, the NEAS populations showed evidence of both isolation by distance and ancient clines, whereas there was no evidence of structure in SEAS populations. Nested cladistic analysis demonstrated that population history events and ongoing demographic processes both contributed to the contrasting patterns of NRY variation in NEAS and SEAS. We conclude that the peopling of East Asia was more complex than earlier models had proposed-that is, a multilayered, multidirectional, and multidisciplinary framework is necessary. For instance, in addition to the previously recognized genetic and dental dispersal signals from SEAS to NEAS populations, CAS has made a significant contribution to the contemporary gene pool of NEAS, and the Sino-Tibetan expansion has left traces of a genetic trail from northern to southern China.

We examined 43 biallelic polymorphisms on the nonrecombining portion of the Y chromosome (NRY) in 50 human populations encompassing a total of 2,858 males to study the geographic structure of Y-chromosome variation. Patterns of NRY diversity varied according to geographic region and method/level of comparison. For example, populations from Central Asia had the highest levels of heterozygosity, while African populations exhibited a higher level of mean pairwise differences among haplotypes. At the global level, 36% of the total variance of NRY haplotypes was attributable to differences among populations (i.e., Phi(ST) = 0.36). When a series of AMOVA analyses was performed on different groupings of the 50 populations, high levels of among-groups variance (Phi(CT)) were found between Africans, Native Americans, and a single group containing all 36 remaining populations. The same three population groupings formed distinct clusters in multidimensional scaling plots. A nested cladistic analysis (NCA) demonstrated that both population structure processes (recurrent gene flow restricted by isolation by distance and long-distance dispersals) and population history events (contiguous range expansions and long-distance colonizations) were instrumental in explaining this tripartite division of global NRY diversity. As in our previous analyses of smaller NRY data sets, the NCA detected a global contiguous range expansion out of Africa at the level of the total cladogram. Our new results support a general scenario in which, after an early out-of-Africa range expansion, global-scale patterns of NRY variation were mainly influenced by migrations out of Asia. Two other notable findings of the NCA were (1) Europe as a "receiver" of intercontinental signals primarily from Asia, and (2) the large number of intracontinental signals within Africa. Our AMOVA analyses also supported the hypothesis that patrilocality effects are evident at local and regional scales, rather than at intercontinental and global levels. Finally, our results underscore the importance of subdivision of the human paternal gene pool and imply that caution should be exercised when using models and experimental strategies based on the assumption of panmixia.

Haplotypes constructed from Y-chromosome markers were used to trace the origins of Native Americans. Our sample consisted of 2,198 males from 60 global populations, including 19 Native American and 15 indigenous North Asian groups. A set of 12 biallelic polymorphisms gave rise to 14 unique Y-chromosome haplotypes that were unevenly distributed among the populations. Combining multiallelic variation at two Y-linked microsatellites (DYS19 and DXYS156Y) with the unique haplotypes results in a total of 95 combination haplotypes. Contra previous findings based on Y- chromosome data, our new results suggest the possibility of more than one Native American paternal founder haplotype. We postulate that, of the nine unique haplotypes found in Native Americans, haplotypes 1C and 1F are the best candidates for major New World founder haplotypes, whereas haplotypes 1B, 1I, and 1U may either be founder haplotypes and/or have arrived in the New World via recent admixture. Two of the other four haplotypes (YAP+ haplotypes 4 and 5) are probably present because of post-Columbian admixture, whereas haplotype 1G may have originated in the New World, and the Old World source of the final New World haplotype (1D) remains unresolved. The contrasting distribution patterns of the two major candidate founder haplotypes in Asia and the New World, as well as the results of a nested cladistic analysis, suggest the possibility of more than one paternal migration from the general region of Lake Baikal to the Americas.

We compared the global pattern of variation at two homologous microsatellites mapping to the long arm of the X chromosome (DXYS156X) and to the short arm of the Y chromosome (DXYS156Y) in humans. A single pair of oligonucleotide primers amplifies these two nonallelic loci, each of which contains polymorphism in the number of pentanucleotide units. We observed 11 alleles in a sample of 2290 X chromosomes and 2006 Y chromosomes from 50 populations representing 6 major geographic regions. The overlapping size range of the X- and Y-chromosome alleles indicated a more complex distribution of alleles at these two loci than previously reported. Contrasting patterns of X-chromosome-linked and Y-chromosome-linked variation were reflected in statistically significant differences in genetic diversity values among geographic regions and between X and Y chromosomes. Higher levels of diversity characterized the DXYS156X locus in Africa (0.799 +/- 0.004) and the DXYS156Y locus in East Asia (0.700 +/- 0.006) compared with populations from other regions. These different patterns of variation can be explained by a combination of processes at both the molecular and population levels, including variable mutation rates, different effective population sizes, and genetic drift.

This study was a continuation of complex research on the gene pool of indigenous Siberian populations conducted at the Institute of Cytology and Genetics, Siberian Division, Russian Academy of Sciences. In the population of South Altaians from the Mendur-Sokkon village, Ust'-Kanskii raion, Altai Republic, polymorphism for the following genetic markers was studied: blood groups ABO, MNSs, Rhesus, Kell, Duffy, and P; erythrocyte acid phosphatase (AcP); phosphoglucomutase 1 (PGM1); haptoglobin (Hp); and transferrin (Tf). The genetic position of South Altaians relative to the populations of the European part of Russia, Siberia, and the Urals was estimated. It was demonstrated that the gene pool of the South Altaian population of Mendur-Sokkon possessed both Caucasoid and Mongoloid genetic characteristics, with the latter prevailing. Genetically, this population is most closely related to Mongols and Nentsis. The genetic distance between South and North Altaians was large; this agreed with earlier genetic data and confirmed anthropological and ethnographic evidence indicating that these two groups had different backgrounds and were at different stages of ethnogenesis.

Five polymorphisms involving two paternally inherited loci were surveyed in 38 world populations (n = 1,631) to investigate the origins of Native Americans. One of the six Y chromosome combination haplotypes (1T) was found at relatively high frequencies (17.8-75.0%) in nine Native American populations (n = 206) representing the three major linguistic divisions in the New World. Overall, these data do not support the Greenberg et al. (1986) tripartite model for the early peopling of the Americas. The 1T haplotype was also discovered at a low frequency in Siberian Eskimos (3/22), Chukchi (1/6), and Evens (1/65) but was absent from 17 other Asian populations (n = 987). The perplexing presence of the 1T haplotype in northeastern Siberia may be due to back-migration from the New World to Asia.

This study continues a series of investigations of the gene pool of native Siberian ethnic groups. In a population of Tundra Nentsi (Northern Samoyeds) and a group of Komi-Zyryans (Finno-Ugrian) (Samburg settlement, Tyumenskaya oblast, Yamalo-Nenetskii Autonomous okrug), gene markers of the following genetic systems were studied: blood groups (ABO, MNSs, Rhesus, Kell, Duffy, and P), erythrocyte acid phosphatase (AcP), phosphoglucomutase 1 (PGM 1), haptoglobin (Hp), and transferrin (Tf). The population of Samburg Tundra Nentsi was shown to have a close genetic relationship with the "core" of the Forest Nentsi population. In Northern Samoyeds, three carriers of the rare allele K (blood group Kell) were found for the first time. It is suggested that this allele was transferred into the population of Tundra Nentsi from Komi. Samburg Tundra Nentsi are found to have the maximum frequency of the allele PGM 1 (Posphoglucomutase 1) among aboriginal populations of northern Asia. Analysis of original data and the literature revealed a significant genetic distance between the Komi and Northern Samoyed populations. It was shown that Samburg Komi occupy an intermediate position between the clusters of Nenets populations and Finno-Ugrians (Komi) living in Komi Republic.

The distribution of a deletion and of an Ava II site in region V of mitochondrial DNA (mtDNA) was studied in five populations of native inhabitants of the Asian part of Russia, including Chukchi, Asian Eskimos, Evenks, Buryats, and Northern Sel'kups. A deletion with a frequency of 6.3% was found only in Buryats, In Chukchi and Eskimos the AvaII site was not found. A maximal frequency of 11.3% was observed in the Evenks. A comparison with published data was conducted; it revealed a gradient of decreasing frequency of the deletion from Southeast Asia to the North, with its complete absence in the circumpolar regions. In the territory of northeast Asia, all three mitotypes are found, formed by a combination of two polymorphic markers of mtDNA region V, which were found earlier in humans in the New World. The data obtained necessitates a more detailed analysis of the population polymorphism of mtDNA in this region of Asia.

The relationship between heterozygosity for 11 polymorphic loci and fertility of women having passed the menopause was studied in North-Siberian tribe North Selkup. Women with low level of heterozygosity were characterized by the highest values of variance of the number of livebirths and the index of early reproductive loss.

Three separate and reproductively isolated populations living at present in boreal forest and tundra area in Eastern Siberia were studied. Blood groups (AB0, MNSs, Rhesus, Duffy, P. Diego), immunoglobulin allotypes--G1m (z, a, x, f), G3m (b, b0, b1, b3, s, t), Hp, Tf, PGM1, AcP, 6-PGD were tested in blood samples obtained from total 570 individuals. Analysis of covariance and variance matrices containing gene frequencies of the Nganasans, Reindeer Chukchi, the Yugaghir and the Evens has revealed major aspects of regional genetic structure which is in good accordance with regional history and geography.

The relationship between heterozygosity for 13 polymorphic loci and fertility of women having passed the menopause was studied in two North-Siberian tribes: Forest Nentzy (N = 108) and Nganasans (N = 68). The number of pregnancies positively correlated with the individual heterozygosity (r = 0.2910 +/- 0.1063; P less than 0.01) in Forest Nentzy, while in Nganasans this correlation was absent. Women with the average level of individual heterozygosity were characterized by minimal values of variation in pregnancies' number and maximal Q index of realized fertility. It is concluded that the average level of individual heterozygosity is optimal for both tribes.

The article comprises the results of the investigation of the frequencies of alleles of 9 gene loci controlling the blood groups, isoenzymes in populations and subpopulations of Cumandinians and Chelkanians. The presence of alleles A2 r(cde) and K at low concentrations was discovered in both groups. The method of genetic distances was used for the investigation of the inter- and intragroup divergence. With respect to certain loci a considerable variation of allelic frequencies from village to village was established.

Nganasans is a small samodyen-speaking ethnic group originated from several clans of reindeer hunters. Pedigree studies revealed no consanguineous matings of uncle-niece, aunt-nephew, first cousins type among 120 families studied. Rather rarely mating between second cousins could be observed. The reviewed traditional kindship system based on bilateral exogamy is an explanation. Data on 12 blood systems and 6 red cell enzymes distribution in two main localities almost totally studied have been presented. No A2, r, K, MS alleles were observed. Hgh frequencies of Ns, R2, Fya, Jka, Gm1 have been found. Diegoa was seen in only one family. Polymorphism on PGM1, 6-PGD, AK and AP, monomorphism on LDH and MDH has been observed.

Family analysis of ABO, MNSs, Rhesus, Duffy and Kell (Kp) in 50 families of nganasans is carried out. Segregation deviations are found in those families where the variation among the children is the widest. The proportion of children from unmarried persons is found to be very small, which supports the existence of traditional monogamic breeding structure in nganasans.

G1m (z, a, x, f) and G3m (g, b0, b1, b3, b5, s, t) allotypes were tested in 1079 Chukchi inhabitants of interior Chukotka and adjacent Kamchatka. Genetic variation at this particular locus is provided by the presence of three haplotypes, namely, za;g, zax;g and za;bO35st, revealed with mean frequencies of 0.748, 0.089 and 0.154, respectively. Traces of Caucasian Gm (f;bO135) haplotype were observed in 9 of 10 populations studied. Judging from its frequency in the whole group (0.009), European admixture in Reindeer Chukchi did not exceed 1.3%. Analysis of covariance and variance matrices containing gene frequencies for 11 polymorphic loci revealed the aspects of genetic structure. Simultaneously, the action of systematic versus nonsystematic pressure was also evaluated and interpreted in the light of historical and ecological events.

Blood groups, immunoglobulin allotypes, serum proteins and red cell enzymes were tested in four populations of Asiatic Eskimos. 12 of 16 gene loci studied were found to be polymorphic. Analysis of covariance and variance matrices for gene frequencies of 8 Bering Sea populations revealed major aspects of regional genetic structure. Regression of average heterozygosity on genetic distance from centroid permitted us to interpret it in the light of counterbalancing action of systematic and non-systematic pressure. Analysis of R matrix containing gene frequencies for both Eskimo and Chukchi populations revealed two different clusters - more heterogeneous Eskimo cluster and less heterogeneous Chukchi cluster. Good fit was observed between regional genetic structure, history and geography.

Chi-square contingency table analysis of phenotypic (genotypic) and gene frequencies of erythrocyte and blood serum groups and enzymes in a group of reindeer hunter and fishermen revealed heterogeneity within the population studied. Four out of twelve loci which have been compared were found to be involved in the process of differentiation into two local subgroups (subpopulations). No statistical differences have been observed between samples arbitrarily representing three generations. The data obtained support the hypothesis that the whole population still preserves the state of the stability. Traditional migration from adjacent populations close to nganasans by language and culture has made an important contribution into heterogeneity found in nganasans.

Aspects of population structure within two of the least disintegrated "anthropological isolates" in north-western (forest Nentsi) and north-central (Nganasani) Siberia were analysed on the basis of 14 polymorphic loci. The mean FIS values were found to be 0.008 in the forest Nentsi and -0.038 in the Nganasani. The negative FIS in the latter may be due to avoidance of close inbreeding. This is not the case with the Forest Nentsi who prefer matings of the uncle-niece and first cousin's type. The mean RST(FST) values of 0.026 for the forest Nentsi and 0.009 for less heterogeneous Nganasani fall within the range of values found in subdivided human groups with a similar pattern of material culture and economy. Analysis of covariance and variance matrices containing gene frequencies for seven forest Nentsi and three Nganasani subdivisions indicate that the population structure of both groups is the product of the counterbalancing action of genetic drift and migration. Pairwise genetic and geographic distance matrices between subpopulations within both groups are highly correlated, allowing us to ascribe more than 90 percent of variation among subdivisions of the Nganasani and almost 70 percent in the forest Nentsi to the effects of geographic barriers, namely distance. Mean locus heterozygosity was found to be higher in the forest Nentsi (0.332) than in the Nganasani (0.286) reflecting pronounced difference in their histories.