鈴木仁 教授 / SUZUKI, Hitoshi

日本列島の生物はおもしろい

鈴木仁 教授 /  SUZUKI, Hitoshi

研究分野・テーマ・内容

研究分野 分子系統地理学
研究テーマ 小型哺乳類の系統進化

研究内容

生物は遺伝情報を刻々と変化させ、変化する環境の中を生き抜いています。この日本列島にも多くの生物種が生息し、進化のドラマが展開されています。遺伝子の比較から、列島には過去数百万年前間、順次大陸から複数系統の哺乳類が渡来し、現在に至っていることが分かってきました。日本という新しい空間で生物はどのような生き方をしているのかに興味を持っています。列島には北海道、本州、四国、九州を始めとする多くの島々で構成され、本州は地形的に複雑です。モグラ類、ネズミ類などで地理的変異の状況を明らかにすることで、系統はなぜ分化するのかという問題にとりくんでいます。

メッセージ

私たちの研究室には純粋に哺乳類の進化史に興味を持つ学生が集まり研究を行っています。日本列島に生息する小型哺乳類を中心に研究を進めており、その奥深さを堪能する毎日です。日本の哺乳類の歴史を研究するには大陸の種との比較が重要で、ロシア、韓国、中国、インドネシア、オーストラリアの研究者とも共同研究を行っています。

参考文献・論文・著書

  • ・「第10章小型哺乳類」, 159-174 (小池裕子,松井正文:『保全遺伝学』 東京大学出版会,東京) 2003
  • ・アジアのネズミ類相の成因に関する時空間要因 94-110.「動物地理の自然史」 増田隆一、阿部永編 北海道大学図書刊行会 2005
  • ・ネズミ類にみる生物の進化と外来種問題 エコソフィア 第17号 36-40. 2006

nameSUZUKI Hitoshi

Research subject

Specialized field

Phylogeny and phylogeography of Mammals

Key words

・Evolutionary history of the Japanese small mammals
・Evolution of coat colors in mammals
・Molecular inference for introgressive hybridization
・Genetic diversity and local adaptation

Research subject

The Japanese Islands comprise a “biodiversity hotspot” that harbors more than 100 indigenous species of mammals, half of which are endemic (Suzuki 2009). The origin of these mammals is of great interest and has been the subject of intense debate from paleontological, zoogeographic, phylogenetic, and taxonomic perspectives. Recent molecular phylogenetic studies of many groups of Japanese mammals, such as rodents, moles, mustelids, and leporids, have suggested exciting new hypotheses regarding the evolutionary history of mammals of the Japanese Islands (Suzuki 2009); the last 10–2 million years of evolutionary activity that has largely shaped the present-day worldwide distribution of mammals, including those of the Japanese Islands. This view of a long mammalian history for Japan stands in contrast with its very poor Tertiary fossil mammal record, and with the associated belief that terrestrial mammals only migrated to Japan rather recently, during the last half million years. By comparing endemic Japanese taxa with their most closely related continental counterparts, however, we are able to quantify the level of genetic endemism of Japanese taxa and estimate their times of divergence and our results indicated that extant mammalian lineages in Japan can be characterized by their level of endemicity, which mostly go back to 2–3 mya and 5–6 mya in the Tertiary.

The Japanese mammal fauna comprises a unique set of species with high a variety of endemicity and their own evolutionary histories. This fauna provides abundant opportunities for studying mammalian evolution, including changes in coat colors, over both long and short time frames (e.g. Kambe et al. 2011; Yasuda et al. 2011).

message

We are now focusing on the evolutionary histories of mammals occurring in the Japanese Islands, with a special emphasis on those have migrated to Japan with ancient peoples from the continent, such as the house mouse (Figure) and black rats (Aplin et al. 2011; Kambe et al. 2011; Nunome et al. 2010; Suzuki and Aplin 2012; Yonekawa et al. 2012). Anyone who has interests in genetic and ecological aspects of the evolution of mammals is welcome.

references

  • Suzuki H. and Aplin K. P. (2012) Phylogeny and biogeography of the genus Mus in Eurasia In: Macholan M, Baird S, Munclinger P, Pilek J (eds) Evolution of the House Mouse, Cambridge University Press (in press)
  • Yonekawa H., Sato J.J., Suzuki H. and Moriwaki K. (2012). Origin and genetic status of Mus musculus molossinus: a typical example for reticulate evolution in the genus Mus. In: Macholan M, Baird S, Munclinger P, Pilek J (eds) Evolution of the House Mouse, Cambridge University Press (in press)
  • Yasuda, S, Iwabuchi, M, Aiba, H, Minato, S, Mitsuishi, K,Tsuchiya, K, Suzuki H. (2011) Spatial framework of nine distinct local populations of the Japanese dormouse Glirulus japonicus based on matrilineal cytochrome b and patrilineal SRY gene sequences. Zoological Science (in press)
  • Aplin K.P., Suzuki H., et al. (2011) Multiple geographic origins of commensalism and complex dispersal history of Black Rats. PLoS One 6(11): e26357.
  • Kambe Y., Tanikawa T., Matsumoto Y, Tomozawa M., Aplin K. P. and Suzuki H. (2011) Origin of agouti-melanistic polymorphism in wild Black Rats (Rattus rattus) inferred from Mc1r gene sequencesZoological Science 28: 560–567.
  • Nunome M., Ishimori C., Aplin K., Tsuchiya K., Yonekawa H., Moriwaki K. and Suzuki H. (2010) Detection of recombinant haplotypes in wild mice (Mus musculus) provides new insights into the origin of Japanese mice. Molecular Ecology 19:2474–2489
  • Suzuki, H. A molecular phylogenetic view of mammals in the “three-story museum” of Hokkaido, Honshu, and Ryukyu Islands. The Wild Mammals of Japan. The Wild Mammals of Japan. Eds., Ohdachi SD, Ishibashi Y, Iwasa MA, Saitoh T. Shoukadoh, Kyoto. pp 261–263.