Research Interests:
Research Interests:
Allele frequencies from seven polymorphic red cell antigen loci (ABO, Rh, MN, S, P, Duffy, and Diego) were examined in 144 Native American populations. Mean genetic distances (Nei's D) and the fixation index FST are... more
Allele frequencies from seven polymorphic red cell antigen loci (ABO, Rh, MN, S, P, Duffy, and Diego) were examined in 144 Native American populations. Mean genetic distances (Nei's D) and the fixation index FST are approximately equal for the North and South American samples but are reduced in the Central American geographic area. The relationship between genetic distance and geographic distance differs markedly across geographic areas. The correlation between geographic distance and genetic distance for the North and Central American data is twice as large as that observed for the South American samples. This geographic difference is confirmed in spatial autocorrelation analyses; no geographic structure is apparent in the South American data but geographic structure is prominent in North and Central American samples. These results confirm earlier observations regarding differences between North and South American gene frequency patterns.
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Mitochondrial DNA lineage frequencies in prehistoric Aleut, eastern Utah Fremont, Southwestern Anasazi, Pyramid Lake, and Stillwater Marsh skeletal samples from northwest Nevada and the Oneota of western Illinois are compared with those... more
Mitochondrial DNA lineage frequencies in prehistoric Aleut, eastern Utah Fremont, Southwestern Anasazi, Pyramid Lake, and Stillwater Marsh skeletal samples from northwest Nevada and the Oneota of western Illinois are compared with those in 41 contemporary aboriginal populations of North America. The ancient samples range in age from 300 years to over 6,000 years. The results indicate that the prehistoric inhabitants of North America exhibit the same level of mtDNA variability as contemporary populations of the continent. Variation in modern mtDNA haplogroup frequencies is highly geographically structured, and the prehistoric samples exhibit the same geographic pattern of variation. This indicates that differentiation of regional patterns of mtDNA lineage variation occurred early in North American prehistory (much more than 2,000 years B.P.), has remained relatively stable since its origin, and was little influenced by the disruptions hypothesized for other genetic systems as a result of population declines and relocations at contact.
Research Interests:
Research Interests:
Research Interests:
Allele frequencies from seven polymorphic red cell antigen loci (ABO, Rh, MN, S, P, Duffy, and Diego) were examined in 144 Native American populations. Mean genetic distances (Nei's D) and the fixation index FST are approximately... more
Allele frequencies from seven polymorphic red cell antigen loci (ABO, Rh, MN, S, P, Duffy, and Diego) were examined in 144 Native American populations. Mean genetic distances (Nei's D) and the fixation index FST are approximately equal for the North and South American samples but are reduced in the Central American geographic area. The relationship between genetic distance and geographic distance differs markedly across geographic areas. The correlation between geographic distance and genetic distance for the North and Central American data is twice as large as that observed for the South American samples. This geographic difference is confirmed in spatial autocorrelation analyses; no geographic structure is apparent in the South American data but geographic structure is prominent in North and Central American samples. These results confirm earlier observations regarding differences between North and South American gene frequency patterns.
Research Interests:
Research Interests:
Academic research focusing on the population and culture history of the Aleut (Unangan) people began in the late 19th century and continues to the present. The papers in this special issue of Human Biology summarize the latest results... more
Academic research focusing on the population and culture history of the Aleut (Unangan) people began in the late 19th century and continues to the present. The papers in this special issue of Human Biology summarize the latest results from archaeological, linguistic, genetic, and morphometric research approaches that bear on our current understanding of Unangan history and prehistory. Although these new analyses have provided a level of description and resolution previously unattainable, explanatory models and mechanisms for the patterned variation observed over time in the biological and cultural record of the Aleutian region remains elusive. Bringing the diverse data sets into concordance to represent an integrated synthesis of Aleut population and culture history and of Unangan origins and their relationships with other groups in the region remains a goal for future investigators.
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The Aleutian Islands were colonized, perhaps several times, from the Alaskan mainland. Earlier work documented transitions in the relative frequencies of mtDNA haplogroups over time, but little is known about potential source populations... more
The Aleutian Islands were colonized, perhaps several times, from the Alaskan mainland. Earlier work documented transitions in the relative frequencies of mtDNA haplogroups over time, but little is known about potential source populations for prehistoric Aleut migrants. As part of a pilot investigation, we sequenced the mtDNA first hypervariable region (HVRI) in samples from two archaeological sites on the Alaska Peninsula (the Hot Springs site near Port Moller, Alaska; and samples from a cluster of sites in the Brooks River area near Katmai National Park and Preserve) and one site from Prince William Sound (Mink Island). The sequences revealed not only the mtDNA haplogroups typically found in both ancient and modern Aleut populations (A2 and D2) but also haplogroups B2 and D1 in the Brooks River samples and haplogroup D3 in one Mink Islander. These preliminary results suggest greater mtDNA diversity in prehistoric populations than previously observed and facilitate reconstruction of...
Research Interests: Ancient History, Genetics, Geography, Demography, Anthropology, and 14 moreBiological Anthropology, Phylogeography, Arctic Archaeology, Human Biology, Phylogeny, Mitochondrial DNA, Humans, Haplotypes, National Park, Genetic variation, Anthropological genetics, Pilot Projects, Prince William Sound, and Alaska
Mitochondrial DNA lineage frequencies in prehistoric Aleut, eastern Utah Fremont, Southwestern Anasazi, Pyramid Lake, and Stillwater Marsh skeletal samples from northwest Nevada and the Oneota of western Illinois are compared with those... more
Mitochondrial DNA lineage frequencies in prehistoric Aleut, eastern Utah Fremont, Southwestern Anasazi, Pyramid Lake, and Stillwater Marsh skeletal samples from northwest Nevada and the Oneota of western Illinois are compared with those in 41 contemporary aboriginal populations of North America. The ancient samples range in age from 300 years to over 6,000 years. The results indicate that the prehistoric inhabitants of North America exhibit the same level of mtDNA variability as contemporary populations of the continent. Variation in modern mtDNA haplogroup frequencies is highly geographically structured, and the prehistoric samples exhibit the same geographic pattern of variation. This indicates that differentiation of regional patterns of mtDNA lineage variation occurred early in North American prehistory (much more than 2,000 years B.P.), has remained relatively stable since its origin, and was little influenced by the disruptions hypothesized for other genetic systems as a resul...
Research Interests:
All published studies on the familial incidence of schizophrenia appropriate for testing the applicability of the general single-locus two-allele model are examined under the assumption of a unitary etiology for all schizophrenia. We show... more
All published studies on the familial incidence of schizophrenia appropriate for testing the applicability of the general single-locus two-allele model are examined under the assumption of a unitary etiology for all schizophrenia. We show that the single major locus model is inadequate to predict the incidence in four classes of relatives of schizophrenic probands (parents, siblings, monozygotic, and dizygotic cotwins). In addition, the observed proportion of affected offspring from dual matings differ significantly from the model's prediction. The lack of an overall fit between the published familial distributions and the monogenic model suggests that a single major locus is insufficient for the etiology of schizophrenia. Further efforts in examining multifactorial models, mixed models, and other transmission models may be fruitful.
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A lymphoma outbreak occurred at the Sukhumi Center in the Late 1960's, when 12 baboons were inoculated with blood from human leukemia patients. Out of a total of 3219 animals, 218 contracted lymphoma and died. This outbreak appears to... more
A lymphoma outbreak occurred at the Sukhumi Center in the Late 1960's, when 12 baboons were inoculated with blood from human leukemia patients. Out of a total of 3219 animals, 218 contracted lymphoma and died. This outbreak appears to be primarily horizontal in transmission. Genetic investigations reveal that: (1) inbreeding does not increase risk of lymphoma; (2) there is a weak association between the PGM2 locus and lymphoma; (3) based upon path analysis, there is evidence of a significant transmissible component (genetic predisposition) passed from the parental to the next generation.
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Dixie West, Dennis O’Rourke, and Michael H. Crawford offer an introduction to the special issue focused on the origins and settlement of the indigenous populations of the Aleutian Archipelago. Pay-Per-View Download To access this article... more
Dixie West, Dennis O’Rourke, and Michael H. Crawford offer an introduction to the special issue focused on the origins and settlement of the indigenous populations of the Aleutian Archipelago. Pay-Per-View Download To access this article as a PDF pay-per-view download via BioOne, please click here.
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Research Interests:
Research Interests: Genetics, Genomics, Phylogeography, Next generation sequencing, Biological Sciences, and 16 morePhylogeny, Environmental Sciences, Mitochondrial DNA, Elephants, Late Pleistocene, Haplotypes, Fossils, Animals, Evolutionary History, Genome, South America, Biological evolution, Mitochondrial Genome, North America, Mammoths, and North American
The New World Arctic, the last region of the Americas to be populated by humans, has a relatively well-researched archaeology, but an understanding of its genetic history is lacking. We present genome-wide sequence data from ancient and... more
The New World Arctic, the last region of the Americas to be populated by humans, has a relatively well-researched archaeology, but an understanding of its genetic history is lacking. We present genome-wide sequence data from ancient and present-day humans from Greenland, Arctic Canada, Alaska, Aleutian Islands, and Siberia. We show that Paleo-Eskimos (~3000 BCE to 1300 CE) represent a migration pulse into the Americas independent of both Native American and Inuit expansions. Furthermore, the genetic continuity characterizing the Paleo-Eskimo period was interrupted by the arrival of a new population, representing the ancestors of present-day Inuit, with evidence of past gene flow between these lineages. Despite periodic abandonment of major Arctic regions, a single Paleo-Eskimo metapopulation likely survived in near-isolation for more than 4000 years, only to vanish around 700 years ago.
Research Interests: Ancient History, Genetics, Archaeology, Prehistoric Archaeology, Human Evolution, and 34 moreHuman Genetics, Genomics, Science, Siberia, Arctic Archaeology, North American archaeology, Indigenous Peoples, Ancient DNA (Archaeology), Ancient DNA Research, Arctic Anthropology, Multidisciplinary, Ancient DNA (Anthropology), Canada, The peopling of the Americas, Mitochondrial DNA, Humans, Arctic, Human Migration, Survivors, Hair, Human Population Genetics, Greenland, American Anthropology and Archaeology, Ancient DNA, Eskimo-Aleut (Siberian Yupik Eskimo), Peopling of the New World, Artefact studies - Siberian and Eskimo, Human Genome, Peopling of the Americas, Tooth, Base Sequence, Ancient DNA of Human Populations, Bone and Bones, and Alaska
Research Interests: Ancient History, Genetics, Archaeology, Technology, Population Genetics, and 25 moreMigration, Science, Siberia, Population Dynamics, Multidisciplinary, Pleistocene, Quaternary, Colonization, Dispersion, Mitochondrial DNA, Population, Humans, Chronology, Late Pleistocene, Colonisation, Americas, Haplotypes, Fossils, Asia, Cenozoic, Homo, Phanerozoic, Deglaciation, Shorelines, and Ice Sheets
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Research Interests: Engineering, Genetics, Physics, Chemistry, RNA, and 17 moreBiology, Medicine, Multidisciplinary, Mitochondrial DNA, Humans, Mutation, Molecular clock, Calibration, Animals, PLoS one, Mitochondrial Genome, Population expansion, Pan troglodytes, Time Factors, Hominidae, Phylogenetic Tree, and Amino Acid Substitution Rates
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Research Interests:
ABSTRACT Zooarchaeological analyses have suggested a possible case of late Holocene resource depression in California tule elk (Cervus elaphus nannodes). We develop and conduct a preliminary independent test of this here based on trends... more
ABSTRACT Zooarchaeological analyses have suggested a possible case of late Holocene resource depression in California tule elk (Cervus elaphus nannodes). We develop and conduct a preliminary independent test of this here based on trends in genetic diversity derived from ancient DNA extracted from archaeological elk bone. Mitochondrial DNA sequence data from 24 tule elk temporally dispersed across the late Holocene deposits of the Emeryville Shellmound, California, provide provisional support for a decline in genetic diversity and a population bottleneck beginning about 1600 B.P. Final confirmation of this pattern must await complete replication of the sequences. Stable isotope analyses of the elk bone provide a record of change in the terrestrial environment across the period of deposition and no suggestion that climate change may have played a role in an elk population decline. The analysis has implications for our understanding of change in human behavior and biology during late Holocene of central California, the methodology of resource depression analyses, and the conservation biology of tule elk.
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When families are ascertained through affected twins, as for example when twin probands are selected from a registry and their non-twin relatives studied, a correction for ascertainment bias is needed. It is shown that probandwise... more
When families are ascertained through affected twins, as for example when twin probands are selected from a registry and their non-twin relatives studied, a correction for ascertainment bias is needed. It is shown that probandwise counting (where relatives of doubly ascertained twin pairs are counted twice) is the appropriate method. The bias resulting from pairwise counting is given and depends on the genetic model and on the probability of selecting an affected twin as a proband. For the multifactorial and generalized single major locus models the bias is small, and the problems associated with nonindependent ascertainment are negligible in practice.