DNA Lineages (dna + lineage)

Distribution by Scientific Domains

Kinds of DNA Lineages

  • mitochondrial dna lineage


  • Selected Abstracts


    Diversity of Mitochondrial DNA Lineages in South Siberia

    ANNALS OF HUMAN GENETICS, Issue 5 2003
    M. V. Derenko
    Summary To investigate the origin and evolution of aboriginal populations of South Siberia, a comprehensive mitochondrial DNA (mtDNA) analysis (HVR1 sequencing combined with RFLP typing) of 480 individuals, representing seven Altaic-speaking populations (Altaians, Khakassians, Buryats, Sojots, Tuvinians, Todjins and Tofalars), was performed. Additionally, HVR2 sequence information was obtained for 110 Altaians, providing, in particular, some novel details of the East Asian mtDNA phylogeny. The total sample revealed 81% East Asian (M*, M7, M8, M9, M10, C, D, G, Z, A, B, F, N9a, Y) and 17% West Eurasian (H, U, J, T, I, N1a, X) matrilineal genetic contribution, but with regional differences within South Siberia. The highest influx of West Eurasian mtDNAs was observed in populations from the East Sayan and Altai regions (from 12.5% to 34.5%), whereas in populations from the Baikal region this contribution was markedly lower (less than 10%). The considerable substructure within South Siberian haplogroups B, F, and G, together with the high degree of haplogroup C and D diversity revealed there, allows us to conclude that South Siberians carry the genetic imprint of early-colonization phase of Eurasia. Statistical analyses revealed that South Siberian populations contain high levels of mtDNA diversity and high heterogeneity of mtDNA sequences among populations (Fst = 5.05%) that might be due to geography but not due to language and anthropological features. [source]


    Ancient DNA evidence for the loss of a highly divergent brown bear clade during historical times

    MOLECULAR ECOLOGY, Issue 8 2008
    SEBASTIEN CALVIGNAC
    Abstract The genetic diversity of present-day brown bears (Ursus arctos) has been extensively studied over the years and appears to be geographically structured into five main clades. The question of the past diversity of the species has been recently addressed by ancient DNA studies that concluded to a relative genetic stability over the last 35 000 years. However, the post-last glacial maximum genetic diversity of the species still remains poorly documented, notably in the Old World. Here, we analyse Atlas brown bears, which became extinct during the Holocene period. A divergent brown bear mitochondrial DNA lineage not present in any of the previously studied modern or ancient bear samples was uncovered, suggesting that the diversity of U. arctos was larger in the past than it is now. Specifically, a significant portion (with respect to sequence divergence) of the intraspecific diversity of the brown bear was lost with the extinction of the Atlas brown bear after the Pleistocene/Holocene transition. [source]


    Geological history and within-island diversity: a debris avalanche and the Tenerife lizard Gallotia galloti

    MOLECULAR ECOLOGY, Issue 12 2006
    RICHARD P. BROWN
    Abstract Several processes have been described that could explain geographical variation and speciation within small islands, including fragmentation of populations through volcanic eruptions. Massive landslides, or debris avalanches, could cause similar effects. Here we analyse the potential impact of the 0.8 million-year-ago (Ma) Güimar valley debris avalanche on the phylogeography of the lizard Gallotia galloti on the Canary Island of Tenerife. Distributions of mitochondrial DNA lineages (based on cytochrome b sequences) were analysed on a 60-km southeastern coast transect centred on this area. Three main clades were detected, which can be divided into northern (one clade) and southern (two clades) groups that introgress across the valley. Maximum-likelihood estimates of migration rates (scaled for mutation rate) revealed highly asymmetric patterns, indicating that long-term gene flow into this region from both the northern and the southern populations greatly exceeded that in the opposite directions, consistent with recolonization of the area. The ancestral Tenerife node on the G. galloti tree is estimated at 0.80 Ma, matching closely with the geological estimate for the debris avalanche. Morphological variation (body dimensions and scalation) was also analysed and indicated a stepped cline in female scalation across the valley, although the patterns for male scalation and male and female body dimensions were not as clear. Together these findings provide support for the hypothesis that the debris avalanche has shaped the phylogeography of G. galloti and may even have been a primary cause of the within-island cladogenesis through population fragmentation and isolation. Current estimates of timing of island unification mean that the original hypothesis that within-island diversity is explained by the secondary contact of populations from the two ancient precursor islands of Teno and Anaga is less plausible for this and some other Tenerife species. Large-scale landslides have occurred on many volcanic islands, and so may have been instrumental in shaping within-island diversities. [source]


    Historical and ecological correlates of body shape in the brook stickleback, Culaea inconstans

    BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2009
    JESSICA LYN WARD
    Using geometric morphometric methods, we evaluated the correlation between phenotypic variation and available historical and habitat information for two genetically differentiated, allopatric lineages of a widespread North American species, the brook stickleback (Culaea inconstans). The results obtained revealed strong patterns of structured phenotypic differentiation across the species range with extreme phenotypes occurring at the northwest and southeast range boundaries. Shape variation was broadly congruent with the distribution of two mitochondrial DNA lineages; a deep-bodied eastern form (Atlantic refugium) and a slim-bodied western form (Mississippian refugium); however, the two forms were not lineage-specific and phenotypic cladistic diversification is likely to be an artefact of underlying clinal variation associated with longitudinal and latitudinal gradients. In addition, we found little evidence of diagnosable lake and river forms across North America. Taken together, large-scale patterns of phenotypic diversity observed in C. inconstans suggest that relatively recent factors, such as continually varying natural selection across the range and/or potential local gene flow, may substantially mitigate the effects of historical separation or a generalized adaptive response to alternative habitats. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 769,783. [source]