Abstract
Genetic diversity in three taiga specialists – the Siberian
tit (Parus cinctus), the Siberian jay
(Perisoreus infaustus) and the Siberian flying
squirrel (Pteromys volans) – was assessed by
comparing DNA sequence variation across the mitochondrial control region
and allele frequencies of microsatellites from samples collected from
Fennoscandia and Siberia. Population sizes of these species have
declined in association with fragmentation and loss of suitable forest
habitat due to modern forestry practices in Fennoscandia. The red
squirrel (Sciurus vulgaris) served as a reference
for the flying squirrel.
Genetic differentiation among species studied ranged from a
panmictic population in the Siberian tit to that of the strong
differentiation of populations
(θST = 53%) in the flying squirrel
in Finland. MtDNA and microsatellite data, together with assignment
studies, showed the Siberian jay population to be significantly
genetically structured and supported the existence of a metapopulation
like structuring in Fennoscandia. Division of genetic variation among
flying squirrel populations along the ancient shoreline of the Littorina
Lymnea Sea stage of the Baltic Sea (7000 BP) and two geographically
associated branches in the minimum spanning network supported a two-way
colonisation history for the species. The Finnish inland appears to have
been colonised from the east in association with the arrival of Norway
spruce. At the same time, Coastal Finland was colonised from the
south-east through the Karelian Isthmus. Gene flow of the species
appeared female biased and restricted. Species exhibiting more
restrictive dispersal characteristics and habitat requirements possessed
stronger population genetic structure than those with opposite
characteristics.
Growth or contractions in population size leave characteristic
signatures in mtDNA that can be studied by comparing different sequence
diversity estimates among populations. I applied this method to the
species studied. Significant differences in nucleotide diversities
indicated restrictions in gene flow among populations in all species
studied. Half of the Siberian jay populations gave a signal of
population size bottleneck.
All the species studied showed differences in their population
genetic structures across their entire distribution ranges consistent
with the multirefugia model, most likely to be attributable to
differences in their ecological characteristics and Pleistocene
histories.
| Identifer | oai:union.ndltd.org:oulo.fi/oai:oulu.fi:isbn951-42-7410-5 |
| Date | 20 August 2004 |
| Creators | Uimaniemi, L. (Leena) |
| Publisher | University of Oulu |
| Source Sets | University of Oulu |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess, © University of Oulu, 2004 |
| Relation | info:eu-repo/semantics/altIdentifier/pissn/0355-3191, info:eu-repo/semantics/altIdentifier/eissn/1796-220X |
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