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Bloom dynamics and population genetics of marine phytoplankton : community, species and population aspects /Härnström, Karolina. January 2009 (has links) (PDF)
Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2009. / Härtill 6 uppsatser.
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Stochastic processes in population geneticsKimura, Motoo, January 1956 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 61-64).
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Phylogeography of Y chromosome haplogroups A & B in AfricaNaidoo, Thijessen 22 April 2015 (has links)
A dissertation submitted to the Faculty of Health Sciences, University of the
Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree
of Master of Science in Medicine
Johannesburg, 2014 / Evolution and historical events over the past 300 000 years have contributed in shaping the
gene pool of sub-Saharan African populations. By examining patterns of Y chromosome
variation, through the screening of single nucleotide polymorphisms (SNPs) and short
tandem repeats (STRs), the present study aimed to characterise the phylogeography of
ancient African Y chromosome haplogroups found in populations across sub-Saharan
Africa, as well as understand the genetic affinities of these populations.
In order to screen the large number of the markers required, seven multiplex single base
extension assays were developed. These were used to refine the resolution of Y
chromosomes commonly found in Africa, but also included a few markers to delineate the
common non-African Y chromosome haplogroups, following a hierarchical screening
process. In total, 1667 males were screened, and these data were compiled together with
comparative published data.
The resultant SNP and STR dataset was used in illustrating, more specifically, the
phylogeographies of haplogroups A and B. The wide geographic distribution of
haplogroup A, together with its position at the root of the phylogeny and high diversity,
support an early diversification of the haplogroup into its subclades, which subsequently
spread across Africa. The distribution of major haplogroup B subclades, however, are
possibly due to post-glacial migrations in the case of haplogroup B-M112, and recent
population expansions, leading to the common presence of haplogroup B-M152 across
sub-Saharan Africa. The spread of haplogroup E, however, created the biggest impact on
African populations; with its expansion likely resulting in the diminished presence of many
of the subclades of haplogroups A and B.
The Y chromosome compositions of present sub-Saharan African populations are, thus, the
result of several diversification events, followed by migration, and mixing of population
groups, over the course of modern human existence.
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Y-chromosome variation in the South African 'coloured' populationMotladiile, Thejane Wilson January 2004 (has links)
A dissertation submitted to the faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Medicine in the Division of Human Genetics. / Genetic polymorphisms within the non-recombining portion of Y-chromosome (NRY) preserve a record of human paternal genetic heritage that has persisted to the present, allowing human evolutionary inference, population affinity and demographic history, to be elucidated. To elucidate the geographic origins of the paternal ancestry of the present- day South African (SA) ‘Coloured’ population, a total sample of 167 individuals consisting of Cape Malay (N=54) and ‘Coloured’ groups from Cape Town (N=48) and Johannesburg (N=65) were analysed at 21 binary and eight short tandem repeat (STR) polymorphic loci within NRY. A SA White sample (present study, N=97) as well as other presumed parental populations were included for comparative analysis. Haplotypes constructed using both biallelic haplogroup and STR haplotype data assisted in resolving the geographic regions of origin of Y-chromosome in these groups. Altogether the proportions of African, European and Asian contributions were estimated to be 0%, 18.5% and 46.3% in the Cape Malay, 31.3%, 25% and 20.1% in the Cape ‘Coloureds’, and 24.6%, 40% and 16.9%, in the ‘Coloured’ group from Johannesburg. Those haplotypes that could not be unambiguously resolved to European or Asian origins were referred to as Eurasian lineages, and constituted 35.2%, 22.9% and 18.5% of Y- chromosomes in the Cape Malays, Cape ‘Coloureds’ and Johannesburg ‘Coloureds’, respectively. While the ‘Coloured’ groups currently residing in Cape Town and Johannesburg were not significantly different from each other, both groups were significantly different from the Cape Malay population. This was further supported from the association of these groups in population trees. For the most part, these data corroborate historical data concerning the history of ‘Coloured’ populations, but is the first study to show how males have contributed in shaping the gene pool of the ‘Coloured’ population from South Africa. / WHSLYP2016
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An investigation into the ancestry of the Malagasy population using variation in the alpha- and beta-globin gene clusterHewitt, Rachel 07 April 2014 (has links)
Thesis (M.Sc. (Med.))--University of the Witwatersrand, Faculty of Health Sciences, 1998. / The issue of Malagasy ancestry has been controversial, and has still not been
completely resolved. The historical, linguistic, archaeological and some genetic
evidence points to the fact that modern Malagasy are the descendants of immigrants
who arrived on the island over the past 2000 years, from South and Southeast Asia,
Africa and the Near East. In more recent centuries, mainly in the twentieth century,
there have been significant numbers of Indian, Chinese and French immigrants. In
addition, archaeological and historical studies of specific regional populations of
Malagasy suggest a complex pattern of internal migration within the island, extending
back in time to the first European contacts with the island in the sixteenth century. The
22 Malagasy ethnic groups may be classified as "highland" or "lowland" depending on
their geographic distribution on the island. Within the ethnic groups, the founding
populations have made different genetic contributions: the highland groups are said to
have a greater Indonesian contribution to their ancestry, while the lowlanders have a
greater African contribution to their ancestry.
Genetic studies on the Malagasy have been limited by small sample sizes, deficiencies
in sampling procedures and in the limited number of polymorphisms studied. In light of
the paucity of written records, the Department of Human Genetics, SAIMR, has
undertaken a large study in Madagascar to reconstruct the biological history of its
people, using genetic variation. This thesis forms a part of this study.
Variation in the a- and p-globin cluster has been extensively studied in many parts of
the world, and has been shown to be population specific, with specific variants having
distinct geographical distributions. Thus haemoglobin and its related disorders have
been the subject of extensive studies for determining the origin(s) of particular
populations. In this study, some of the a- and p-globin variation present in the Malagasy
was characterised. Seven RFLPs/HVRs in the a-globin gene cluster and seven RFLPs
in the p-globin gene cluster were analysed. The common a- and p-globin gene cluster
haplotypes differ between African and Asian populations. Frequencies also vary
between populations in a specific geographical regions. The aim of this study was to
characterise the haplotypes present in the Malagasy, to provide information on the
relative genetic contributions of different populations to the peoples of Madagascar.
DNA samples from randomly selected, haematologically normal individuals were
analysed. Individuals were chosen from six Malagasy ethnic groups: two “highland”
populations (Merina and Betsileo), two “lowland" populations (Antasaka and Tsimiheti)
and two populations from the south-west of the island (Mahafaly and Vezo). The groups
chosen cover a broad range of Madagascar and thus provide some representation of
the Malagasy population as a whole. The number of individuals studied in each ethnic
group are as follows: Merina: 88; Betsileo: 78; Antasaka: 67; Tsimiheti: 67; Mahafaly:
26; Vezo: 25.
The frequencies of the a- and (B-globin RFLP sites and a-globin HVRs in the Malagasy
vere calculated. 5' and 3’ p-globin haplotypes were constructed on the basis of
homozygosity. A maximum-likelihood algorithm was used to obtain frequencies of 5’
P-globin haplotypes that could not be assigned on the basis of homozygosity. These
data were then subject to statistical analysis. The frequencies of the 5’ p-globin
haplotypes (consisting of the five sites Hindi 5' to e, Hindi 11 within Gy and Ay, Hindi
within \|/P and 3' to it) were the most informative data set for comparing the Malagasy
ethnic groups to each other and to other world populations. Unfortunately, the
maximum-likelihood estimates of 5‘ p-globin haplotypes could not be used for
comparative analyses due to the lack of similar data in other populations. However
the strong correlation between the maximum-likelihood frequencies and the
observed frequencies illustrated the ability of the algorithm to determine hapiotype
frequencies from otherwise uninformative individuals.
5’ p-globin haplotypes were assigned unambiguously for 248 Malagasy
chromosomes. Ten haplotypes were found; of these, nine have been reported
previously in other world populations and one has not been reported and hns thus
been called “rare” in this study. The frequencies of unambiguous 5’ p-globin
haplotypes in the Malagasy and the proposed parental populations were initially
analysed with x2 tests. For a more accurate comparison between these
populations, genetic distances were calculated and used for the construction of
phylogenetic trees, principle component analysis was carried out, and a study of
heterozygosity versus distance from the centroid was performed. Admixture
estimates of two African populations and one Indonesian population to Malagasy
ancestry were calculated.
Certain general trends were noted in all the analyses. The results are in agreement
with the historical data which provides evidence for both African and Asian
contributions to Malagasy ancestry. The highlanders were more closely affiliated to
the Indonesian/Polynesian populations, while the south-west groups showed the
strongest associations with the African populations. The lowlanders were
consistently intermediate in position between the highlanders and the south-west
groups, with the Antasaka being slightly more closely related to the African
populations than the Tsimiheti. The Malagasy were shown to have high
heterozygosities, similar to those of African populations, and this high degree of
diversity is probably a reflection of the many sources of ancestry of the Malagasy.
The south-west groups were the furthest outliers in the model of heterozygosity
versus distance from the centroid, suggesting that these groups are the most
genetically admixed of all the Malagasy groups that were studied. Estimates of
ancestral population admixture confirmed these trends, with the highlanders having
the highest proportional contribution by Indonesians (53%), but the lowest total
African contribution (47%), while the south-west groups have the highest Bantu
contribution (65%). The Indonesian and African contributions to the lowlanders are
intermediate between those to highlanders and south-west groups. Overall the
Malagasy subjects included in this study showed a 61% African admixture
contribution and a 39% Indonesian admixture contribution.
It is hoped that the results obtained in this study will contribute to the larger project
concerning the origins of the Malagasy, and that they may be used to shed further
light on the much debated issue of Malagasy ancestry.
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Genetic disequilibria and the interpretation of population genetic structure in Daphnia /Berg, Lars M., January 2001 (has links)
Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 5 uppsatser.
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Molecular ecology of Dawson's burrowing bee Amegilla dawsoni (Hymenoptera: Anthophorini) /Beveridge, Maxine. January 2006 (has links)
Thesis (M.Sc.)--University of Western Australia, 2006.
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Mariages et marqueurs génétiques en Capcir (Pyrénées-Orientales)Bataille, Christian. January 1975 (has links)
Thesis. / eContent provider-neutral record in process. Description based on print version record.
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When can genetic information be used to measure inter-population movement? /Brennan, Julie M. January 1900 (has links)
Thesis (Ph.D.) - Carleton University, 2007. / Includes bibliographical references (p. 102-109). Also available in electronic format on the Internet.
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APOE haplotypes in health, lessons from an Oklahoman African American populationObregon Tito, Alexandra de. January 2010 (has links) (PDF)
Thesis--University of Oklahoma. / Bibliography: leaves 61-68.
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