Study on the mechanism of biodiversity creation and maintenance in the most isolated oceanic islands, Hawaii

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H04607
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Biodiversity/Systematics
• Research Institution: Kyoto University
• Principal Investigator: Isagi Yuji 京都大学, 農学研究科, 教授 (50325130)
• Co-Investigator(Kenkyū-buntansha): 小野田 雄介 京都大学, 農学研究科, 准教授 (70578864) ; 伊津野 彩子 国立研究開発法人森林研究・整備機構, 森林総合研究所, 研究員 (80816249)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 生物多様性 / ゲノム解析 / 島嶼生態系 / 形態形質分化 / デモグラフィー

Outline of Final Research Achievements

Intensive measurements for morphological traits and physiological characteristics, and genome analysis were carried out for Meterosideros polymorpha, which is undergoing adaptive evolution to various environments in Hawaii islands. As for the leaf traits with remarkable intraspecific polymorphism, M. polymorpha was adapted to a wide range of environments by combining multiple leaf traits adapted to different environments. M. polymorpha was largely genetically differentiated at the island level regardless of its morphological traits, suggesting that the small part of genomes form the polymorphisms. As a result of estimating population dynamics over the past several million years based on coalescent theory, we found that the populations growing in different environments on the Hawaiian Islands have undergone unique population dynamics.

Free Research Field

分子生態学、森林生態学

Academic Significance and Societal Importance of the Research Achievements

世界的な生物多様性ホットスポットであるハワイ諸島における生物多様性の創出過程を対象にして、環境適応に関与する生物形質や種内多形の形成過程を、野外調査と大規模な集団ゲノム解析で明らかにすることは、学術的に意義深い。きわめて大きな種内形態変異の理解は、被子植物全体にみられる多様な形態形質の進化の理解にもつながり、また、人為撹乱・気候変動に対する樹木集団の応用予測や、保全価値評価、合理的保全ユニットの設定等も可能にするものである。