Geographic range contraction and exploitation of geothermal area, two different responses to the Pleistocene climate change by a temperate lizard

• Project/Area Number: 16K18602
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Biodiversity/Systematics
• Research Institution: Kyoto University
• Principal Investigator: Okamoto Taku 京都大学, 理学研究科, 助教 (80554815)
• Research Collaborator: Tokuda Tatsuhiro ; Kuriyama Takeo
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000); Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
• Keywords: 爬虫類 / 系統地理学 / 季節性 / 寒冷地 / 地理的変異 / 系統地理 / 第四紀気候変動 / 生活史 / 温度生態 / 遺伝的変異 / 歴史生物地理

Outline of Final Research Achievements

Genetic vairation of Plestiodon finitimus (Scincidae, Reptilia) was studied based on DNA markers and morphology, and the following historical biogeography was suggested: the lineages of central and northeastern Japan were diverged by uplift of the central highland of Honshu in Pliocene; the northeastern Japan lineage was diverged into the assemblages of Tohoku and Kanto Districts, and the latter assemblage has expanded its geographic range in the postglacial paried and formed complicated genetic structure in Tohoku District. A survey on reproductive cycle based on estimation of age composition and gonad cycle in each season clarified geographic variation in reproductive phenology in this species, depending on climate irrespective of genetic lineages. On the other hand, a preliminary analysis by ecological niche modeling implied geographic differentiation in niche preference between diverged genetic groups in norther Japan.

Academic Significance and Societal Importance of the Research Achievements

東日本は暖温帯から冷温帯に渡る幅広い気候域を含み，第四紀気候変動により各地の気候と植生が著しく変化してきた．この地域に現在広域している陸上脊椎動物には，氷期に分布が南部へ縮小し，後氷期になってから北方の集団が成立したというモデルにあてはまる変異パタンを示すものが多く知られている．一方，ヒガシニホントカゲの北日本の集団は，左記モデルにあてはまる集団とそうでない集団が混在していると考えられ，氷期の寒冷化に対し，南方への分布縮小と寒冷地への耐性獲得という異なる応答を同時に示した可能性がある．よって，本種は外温動物における温度生態の進化を考察するための有力な題材となる可能性があるといえる．

Research Products

• [Presentation] ヒガシニホントカゲ（トカゲ科，爬虫綱）の繁殖生態の地理的変異（予報） (2018)
  • Author(s): 岡本卓・鈴木大・徳田龍弘・栗山武夫
  • Organizer: 日本爬虫両棲類学会
• [Presentation] ヒガシニホントカゲの外部形態の地理的変異 (2017)
  • Author(s): 岡本卓・山川真徳
  • Organizer: 日本爬虫両棲類学会 第56回大会
• [Presentation] 遺伝的・形態的に分化したヒガシニホントカゲ2群間における生息適地の比較 (2017)
  • Author(s): 塚本誠太・岡本卓・本川雅治・黒尾正樹
  • Organizer: 日本爬虫両棲類学会 第56回大会
• [Presentation] Comparative phylogeography of three species of Plestiodon (Scincidae, Squamata) occurring in the Japanese Islands (2017)
  • Author(s): Taku Okamoto and Tsutomu Hikida
  • Organizer: The 7th International Symposium on Asian Vertebrate Species Diversity
  • Int'l Joint Research
• [Presentation] Genetic variation and historical biogeography of Plestiodon finitimus (Scincidae, Squamata) in northern part of the Japanese main islands (2016)
  • Author(s): Okamoto, T., Kuriyama, T., and Hikida, T
  • Organizer: The 8th World Congress of Herpetology
  • Place of Presentation: 中国 杭州
  • Year and Date: 2016-08-15
  • Int'l Joint Research
• [Presentation] Genetic and Morphological Variations of Plestiodon finitimus in Northern Japan (2016)
  • Author(s): Tsukamoto, S., Kuro-o, M., and Okamoto, T.
  • Organizer: The 6th International Symposium on Asian Vertebrate Species Diversity
  • Place of Presentation: 中国 杭州
  • Int'l Joint Research
• [Presentation] 北日本におけるヒガシニホントカゲの遺伝的・形態的変異 について (2016)
  • Author(s): 塚本誠太，黒尾正樹，岡本卓，本川雅治
  • Organizer: 第55回 日本爬虫両棲類学会 大会
  • Place of Presentation: 琉球大学（沖縄県西原町）
• [Presentation] 日本産陸生爬虫類の歴史生物地理 ～地理的分布と分岐年代の比較分析～ (2016)
  • Author(s): 岡本卓
  • Organizer: 生物群横断系統地理ワークショップ
  • Place of Presentation: 京都大学
  • Invited