Molecular phylogeography of the brown bear (Ursus arctos) in eastern Eurasia
The mammal fauna of the Japanese islands, especially Hokkaido had experienced the repeated colonization of the animals from the Eurasian Continent during the Pleistocene glacial periods. T he brown bear ( Ursus arctos ) is widely distributed on the Holarctic region, and occurs only on Hokkaido and a...
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| Other Authors: | , , , , |
| Format: | Other/Unknown Material |
| Language: | English |
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Hokkaido University
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| Online Access: | http://hdl.handle.net/2115/68570 https://doi.org/10.14943/doctoral.k12700 |
| Summary: | The mammal fauna of the Japanese islands, especially Hokkaido had experienced the repeated colonization of the animals from the Eurasian Continent during the Pleistocene glacial periods. T he brown bear ( Ursus arctos ) is widely distributed on the Holarctic region, and occurs only on Hokkaido and adjacent southern Kuril Islands (Kunashiri and Etorofu) in Japan . To clarify the migration history of the brown bears in Hokkaido and adjacent insular populations, resolving detail ed phylogenetic relationships and estimating the precise timings of the population immigrations to Hokkaido are needed . In addition, it is necessary to reveal the detailed genetic structure of the brown bears across the Eurasian Continent, which could be the evolutionary source of the Hokkaido brown bears. Furthermore, t he brown bear show s male - biased dispersal and female philopatry. Thus, most of the previous studies using maternally inherited mitochondrial DNA ( mtDNA ) markers might not represent the comp rehensive phylogeographic history of the brown bears. Considering the sex - biased migration for the evolutionary history of the brown bear is essential , and it is needed to uncover the paternal phylogeographic structuring of the brown bear . In C hapter I, c omplete mtDNA sequences of 35 brown bears from Hokkaido, the southern Kuril Islands (Kunashiri and Etorofu ), Sakhalin Island, and the Eurasian Continent ( Ural Mountains, European Russia, Bulgaria, and Tibet), and those of four polar bears were analyzed . Ba sed on these sequences, I reconstructed the maternal phylogeny of the brown bear and estimated divergence times of brown bear lineages . The brown bear on Hokkaido was divided into distinct maternal lineages (central, eastern, and southern Hokkaido), and th ree independent migrations to the island could have occurred . Although Sakhalin Island is considered to be a transient area for ancestors of the Hokkaido brown bears, the Sakhalin brown bear grouped with eastern European and western Alaskan brown bears. Thus, ... |
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