Global dispersal and diversification in beetles with flight polymorphisms

2019 Fiscal Year Final Research Report

• Project/Area Number: 15H02637
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Evolutionary biology
• Research Institution: Kyoto University
• Principal Investigator: Sota Teiji 京都大学, 理学研究科, 教授 (00192625)
• Co-Investigator(Kenkyū-buntansha): 池田 紘士 弘前大学, 農学生命科学部, 准教授 (00508880) ; 高見 泰興 神戸大学, 人間発達環境学研究科, 准教授 (60432358)
• Project Period (FY): 2015-04-01 – 2020-03-31
• Keywords: 種多様性 / 全球的分散 / 甲虫類 / 飛翔多型 / 分子系統 / 分岐年代 / 適応 / 種分化

Outline of Final Research Achievements

To clarify the role of the loss of flight ability in the species diversification process of ground-living beetles in the world, molecular phylogeographic analyses were performed for three groups with flight polymorphisms, Cicindelidae, Carabinae, and Silphinae. These groups were estimated to have diverged in the Jurassic to Cretaceous, and in all of them, basal lineages with deep branching were distributed in the lands of Gondwana origin such as Africa, South America, and Australia, and their species diversity were generally low. Loss of flight ability is observed in most groups of Carabinae, in the basal groups and some of the derived groups in Cicindelidae, and only in the derived groups of Silphinae. The flightlessness was related to low species diversity in the basal lineages of Cicindelidea, whereas it was related to increased species diversity in Carabinae and Silphinae.

Free Research Field

進化生態学

Academic Significance and Societal Importance of the Research Achievements

全生物種の２割を占める甲虫類がどのように多様化してきたかは進化生物学の主要テーマとなってきた．これまでの主要な仮説は植物食への適応であるが，植物食は多くの昆虫で進化しており，必ずしも甲虫類の多様化を特徴づけるものではない．本研究では，甲虫類に頻繁に見られる飛翔能力の退化が種多様性をもたらしたという仮説をたて，地表性甲虫を対象にして検証を行った．飛翔能力の退化は分散能力の低下をもたらすため，一方向的に種の多様化と結びつくことは予想されない．中生代以降の大陸変遷と甲虫類の系統進化において，飛翔能力の退化が種多様性の増加・減少にもたらした影響を明らかにしたことが本研究の主要な成果である．