Abstract
Analyses of mitochondrial control region sequences were used to infer phylogeny of
Anser species, phylogeography of the lesser white-fronted goose, and
genetic background of a captive stock.
The genetic distances among the Anser species ranged from
0.9 to 5.5% in the complete control region sequences and supported the view of close
relatedness of these species. Among the four most closely related species, the bean,
pink-footed, white-fronted and lesser white-fronted goose, the branching order is uncertain.
The short internal branches and low support for the branching order suggest that the species
have diverged recently within short time-intervals. The mtDNA tree obtained is incongruent
with the traditional view of the species relationships, but the reasons for this remain to
be clarified.
Two diverged mitochondrial lineages were found in the lesser white-fronted
goose and a refugial origin was proposed. Basal haplotypes are geographically widespread and
indicate a recent common ancestry for populations. The derived haplotypes are confined to
singular breeding populations and suggest restrictions to the present female gene flow. A
shift in the frequency of the mtDNA lineages approximately coincides with a migratory divide
in the Taimyr Peninsula. Low mtDNA diversity and significant difference in the haplotype
frequencies observed in Fennoscandian subpopulation suggested that it should be considered
as a management unit. The fossil record was examined to gain additional information about
the colonisation history of the species, but was found to be of limited use.
The captive lesser white-fronted goose stock used for reintroduction/restocking
was shown to be incompatible with the Fennoscandian wild population. Some captive
individuals carried the mtDNA of the white-fronted goose suggesting a hybrid origin.
Hybridisation has probably occurred during captive propagation, but to clarify further the
extent of introgression, nuclear markers should be applied.
The structure and evolution of the control region were studied by comparing
complete avian sequences. Saturation was found to occur at pairwise divergences of 10% as
shown for third codon positions of the mitochondrial genes previously. In pairwise
comparisons of the control region and cytochrome b sequences, the rate
of divergence varied among the lineages. Two conserved sequence blocks showed considerable
sequence conservation when compared to mammalian sequences.
| Identifer | oai:union.ndltd.org:oulo.fi/oai:oulu.fi:isbn951-42-5948-3 |
| Date | 28 March 2001 |
| Creators | Ruokonen, M. (Minna) |
| 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, 2001 |
| Relation | info:eu-repo/semantics/altIdentifier/pissn/0355-3191, info:eu-repo/semantics/altIdentifier/eissn/1796-220X |
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