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Segawa T, Yonezawa T, Mori H, Akiyoshi A, Allentoft ME, Kohno A, Tokanai F, Willerslev E, Kohno N, Nishihara H. Ancient DNA reveals multiple origins and migration waves of extinct Japanese brown bear lineages. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210518. [PMID: 34386259 PMCID: PMC8334828 DOI: 10.1098/rsos.210518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
Little is known about how mammalian biogeography on islands was affected by sea-level fluctuations. In the Japanese Archipelago, brown bears (Ursus arctos) currently inhabit only Hokkaido, the northern island, but Pleistocene fossils indicate a past distribution throughout Honshu, Japan's largest island. However, the difficulty of recovering ancient DNA from fossils in temperate East Asia has limited our understanding of their evolutionary history. Here, we analysed mitochondrial DNA from a 32 500-year-old brown bear fossil from Honshu. Our results show that this individual belonged to a previously unknown lineage that split approximately 160 Ka from its sister lineage, the southern Hokkaido clade. This divergence time and fossil record suggest that brown bears migrated from the Eurasian continent to Honshu at least twice; the first population was an early-diverging lineage (greater than 340 Ka), and the second migrated via Hokkaido after approximately 160 Ka, during the ice age. Thus, glacial-age sea-level falls might have facilitated migrations of large mammals more frequently than previously thought, which may have had a substantial impact on ecosystem dynamics in these isolated islands.
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Affiliation(s)
- Takahiro Segawa
- Center for Life Science Research, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan
| | - Takahiro Yonezawa
- Tokyo University of Agriculture, 1737 Funako, Atsugi City, Kanagawa, Japan
| | - Hiroshi Mori
- National Institute of Genetics, Yata 1111, Mishima City, Shizuoka, Japan
| | - Ayumi Akiyoshi
- National Institute of Polar Research, Midori-cho 10-3, Tachikawa City, Tokyo, Japan
| | - Morten E. Allentoft
- Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
- Lundbeck Foundation GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - Ayako Kohno
- Department of Geology and Paleontology, National Museum of Nature and Science, Tokyo, Amakubo, Tsukuba, Ibaraki, Japan
| | - Fuyuki Tokanai
- Faculty of Science, Yamagata University, Jonan 4-3-16, Yonezawa City, Yamagata 990-3101, Japan
| | - Eske Willerslev
- Lundbeck Foundation GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Zoology, University of Cambridge, Cambridge, UK
- Wellcome Trust Sanger Institute, Hinxton, UK
| | - Naoki Kohno
- Department of Geology and Paleontology, National Museum of Nature and Science, Tokyo, Amakubo, Tsukuba, Ibaraki, Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennoudai, Tsukuba, Ibaraki, Japan
| | - Hidenori Nishihara
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-S2-17 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
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