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Sökning: WFRF:(Pamilo Pekka)

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1.
  • Berglind, Sven-Åke, 1961- (författare)
  • Population Dynamics and Conservation of the Sand Lizard (Lacerta agilis) on the Edge of its Range
  • 2005
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The sand lizard (Lacerta agilis) reaches the northern periphery of its distribution in south-central Sweden, where small, isolated relict populations occur in pine heath forests on sandy sediments. Modern forestry and fire suppression have reduced the amount of suitable open habitat for the species in this area and seem to be important for its decline. Main objectives of this thesis were to evaluate the efficiency of different management strategies, and if the sand lizard can function as an umbrella species for biodiversity conservation. Over a 16-year period, the estimated annual numbers of adult females in each of two study populations fluctuated between 23 and 3. Simulations of stochastic future population growth showed that the risk of extinction was highly dependent on population growth rate, which in turn was strongly affected by juvenile survival as indicated by elasticity analysis. Simulations of population growth for 50 years showed that the quasi-extinction risk (threshold ≤ 10 females) was > 56% for patches ≤ 1 ha; which is the observed average size of suitable habitat for inhabited patches during a 10-year period. In managed metapopulation networks with highly co-fluctuating local populations, among-population dispersal was not important to reduce extinction risks over a 50-year horizon. In the field the preferred microhabitat of sand lizards was successfully restored using tree felling and patch-soil scarification. The lizards gradually colonized the restored patches, and 16 years after restoration, sand lizards where mainly found there. Pine-heath area, and patch area within individual pine heaths, were of major importance for long-term population persistence at regional and landscape scales, respectively. Analyses of nested species subsets and an umbrella index suggest that the sand lizard can be a useful cross-taxonomic umbrella species on both scales for other red-listed species.
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2.
  • Goropashnaya, Anna, 1964- (författare)
  • Phylogeographic Structure and Genetic Variation in Formica Ants
  • 2003
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The aim of this thesis is to study phylogeny, species-wide phylogeography and genetic diversity in Formica ants across Eurasia in connection with the history of biotic responses to Quaternary environmental changes.The mitochondrial DNA phylogeny of Palaearctic Formica species supported the subgeneric grouping based on morphological similarity. The exception was that F. uralensis formed a separate phylogenetic group. The mitochondrial DNA phylogeny of the F. rufa group showed the division into three major phylogenetic groups: one with the species F. polyctena and F. rufa, one with F. aquilonia, F. lugubris and F. paralugubris, and the third one with F. pratensis.West-east phylogeographic divisions were found in F. pratensis suggesting post-glacial colonization of western Europe and a wide area from Sweden to the Baikal Lake from separate forest refugia. In contrast, no phylogeographic divisions were detected in either F. lugubris or F. exsecta. Contraction of the distribution range to a single refugial area during the late Pleistocene and the following population expansion could offer a general explanation for the lack of phylogeographic structure across most of Eurasia in these species.Sympatrically distributed and ecologically similar species F. uralensis and F. candida showed clear difference in the phylogeographic structure that reflected difference in their vicariant history. Whereas no phylogeographic divisions were detected in F. uralensis across Europe, F. candida showed a well-supported phylogeographic division between the western, the central and the southern group.In socially polymorphic F. cinerea, the overall level of intrapopulation microsatellite diversity was relatively high and differentiation among populations was low, indicating recent historical connections. The lack of correspondence between genetic affinities and geographic locations of studied populations did not provide any evidence for differentiating between alternative hypotheses concerning the directions and sources of postglacial colonization of Fennoscandia.
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  • Goropashnaya, Anna V., et al. (författare)
  • Phylogenetic relationships of Palaearctic Formica species (Hymenoptera, Formicidae) based on mitochondrial cytochrome b sequences
  • 2012
  • Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:7, s. e41697-
  • Tidskriftsartikel (refereegranskat)abstract
    • Ants of genus Formica demonstrate variation in social organization and represent model species for ecological, behavioral, evolutionary studies and testing theoretical implications of the kin selection theory. Subgeneric division of the Formica ants based on morphology has been questioned and remained unclear after an allozyme study on genetic differentiation between 13 species representing all subgenera was conducted. In the present study, the phylogenetic relationships within the genus were examined using mitochondrial DNA sequences of the cytochrome b and a part of the NADH dehydrogenase subunit 6. All 23 Formica species sampled in the Palaearctic clustered according to the subgeneric affiliation except F. uralensis that formed a separate phylogenetic group. Unlike Coptoformica and Formica s. str., the subgenus Serviformica did not form a tight cluster but more likely consisted of a few small clades. The genetic distances between the subgenera were around 10%, implying approximate divergence time of 5 Myr if we used the conventional insect divergence rate of 2% per Myr. Within-subgenus divergence estimates were 6.69% in Serviformica, 3.61% in Coptoformica, 1.18% in Formica s. str., which supported our previous results on relatively rapid speciation in the latter subgenus. The phylogeny inferred from DNA sequences provides a necessary framework against which the evolution of social traits can be compared. We discuss implications of inferred phylogeny for the evolution of social traits.
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  • Goropashnaya, Anna V., et al. (författare)
  • Phylogeography and population structure in the ant Formica exsecta (Hymenoptera, Formicidae) across Eurasia as reflected by mitochondrial DNA variation and microsatellites
  • 2007
  • Ingår i: Annales Zoologici Fennici. - 0003-455X .- 1797-2450. ; 44:6, s. 462-474
  • Tidskriftsartikel (refereegranskat)abstract
    • Phylogeography and population structure of the ant Formica exsecta was studied across Eurasia by using mtDNA sequences and microsatellite genotypes. The phylogeny based on 1.5 kb mtDNA fragment including the cytochrome b and part of the ND6 gene showed significant division (1.63% of nucleotide divergence) between a haplotype from Tibet and all other haplotypes. Similar to findings in diverse array of species associated with forest in Eurasia, the mtDNA phylogeny revealed no evidence for vicariant events due to separation in different forest refugia over glacial periods. The haplotype network includes several small clades (with 2-4 haplotypes in each) with geographically limited distribution, but one geographical region may have received haplotypes from two or more of such clades. This pattern could indicate mixing of different gene pools during postglacial colonization of Europe from different forest refugia or from an ancestral source with some spatial genetic differentiation. The genealogy and the haplotype frequencies suggest postglacial colonization of Siberia from a single refugial source of limited size. Maternal and biparental DNA markers indicated a moderate but significant level of population differentiation (mtDNA Phi(ST) = 0.42, microsatellite F-ST = 0.13) across Eurasia. However, no correlation between genetic differentiation estimated for mtDNA and microsatellites was found among the populations. Considerable reduction in microsatellite genetic diversity was found in the small population of F. exsecta in England, giving some basis to classify this population as near threatened.
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7.
  • Goropashnaya, Anna V, et al. (författare)
  • Recent speciation in the Formica rufa group ants (Hymenoptera, Formicidae) : inference from mitochondrial DNA phylogeny
  • 2004
  • Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 32:1, s. 198-206
  • Tidskriftsartikel (refereegranskat)abstract
    • This study examines phylogenetic relationships among six species of the Formica rufa group ants (F. polyctena, F. rufa, F. lugubris, F. paralugubris, F. aquilonia, and F. pratensis). The phylogeny based on a 2051bp fragment of mtDNA including cyt b, tRNASer, and ND1 genes supports the division of the group into three major clusters: one with the species F. polyctena and F. rufa, one with F. aquilonia, F. lugubris, and F. paralugubris, and the third one with F. pratensis. The interspecific divergence estimates (mean 0.98 +/- 0.15% for the main phylogenetic groups) imply that radiation took place during the Pleistocene. Comparison of the divergence estimates among the F. rufa group species with divergence estimates among other closely related species of insects suggests that speciation in the group was relatively fast, and the mitochondrial lineages of F. polyctena and F. rufa have not fully separated. The haplotype tree shows also signs of transfer of mtDNA between species through hybridisation. The distribution of polygyny (multiple queens per nest) along the branches of the tree indicates that the social type characterised by highly polygynous societies and large colonial networks, has originated at least three times. The species F. aquilonia and F. paralugubris that build such large supercolonies, cluster tightly together with very little nucleotide variation, suggesting that this type of social organisation could be a factor promoting speciation in the ants.
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  • Resultat 1-10 av 13

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