| Autor: |
O'Corry-Crowe, G. M., Suydam, R. S., Rosenberg, A., Frost, K. J., Dizon, A. E. |
| Předmět: |
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| Zdroj: |
Molecular Ecology; Oct1997, Vol. 6 Issue 10, p955-970, 16p |
| Abstrakt: |
The recent evolutuonary history, population structure and movement patterns of beluga whales in the western Neartic were inferred from an analysis of mitochondrial DNA control region sequence variation of 324 whales from 32 locations representing five summer concentrations areas in Alalaska and north-west Canada. Phylogenetic relationships among haplotypes were infererd from parsimonious networks, and genetic subdivision was examined using haplotypic frequency-based indices and an analysis of variance method modified for use with interhaplotypic distance data. MtDNA realationships were characterized by a series of star-like phylogenies which, when viewed in conjunction with infromation on haplotype frequency and distribution, suggested a rapid radiation of beluga whales into the western Neartic following the Pleistocene, and an early divergence of the Beaufort Sea from the Chucki and Bering Seas subpopulations. Overall nucletide diversity was low (0.51%) yet all major summering concentrations were significanyly differentiated (ΦST=0.33) from one another. Stratification of samples by gender and age from the three northermost subpopulations suggested that female cohorts from neighboring subpopulations were most differentiated than males. Further stratification of adult animals by age revealed that oldetr adults were substantially less subdivided among locations thah younger adults, particularly for males suggesting that dispersal, although limited, is biased toward aolder adult males. Overall, the patterns of mtDNA variation in beluga whales indicated that the summering concentrations are demographically, if not phyletically distinct. Population structure appears to be maintained primarily by natal homing behaviour, while asymmetries in dispersal may be associated with the type of mating system. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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