Taxon cycle driven by extinction: an example of terrestrial molluscs crossing the sea

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15872
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: University of the Ryukyus (2022); Tohoku University (2020-2021)
• Principal Investigator: Hirano takahiro 琉球大学, 理学部, 助教 (20808654)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 進化 / 系統地理 / 集団遺伝 / 分子系統 / 種分化 / 南西諸島 / 軟体動物

Outline of Final Research Achievements

I attempted to elucidate the process of species diversification using molecular phylogenetics, population genetics, molecular genomics, and paleobiological methods, focusing on terrestrial and freshwater molluscs inhabiting the East Asian region including Japan. In particular, I examined dispersal patterns, with particular emphasis on islands, revealing genetic differentiation occurring in darwinian islands. Extinctions and invasions occurred repeatedly in ancient lakes, leading to speciation of endemic species. In both island and lake systems, independently evolving similar morphologies were observed. Based on these findings, geographic isolation and adaptive evolution in the new habitats may be the major factors driving species diversification in these molluscs.

Free Research Field

進化生態学

Academic Significance and Societal Importance of the Research Achievements

「進化の実験場」と呼ばれる海洋島や古代湖などでいかにして種多様化が生じるか、高い種分化率を誇る陸・淡水産貝類でそのプロセスの一端を解明できたことは、進化生態学的意義が大きい。特に、耐塩性に乏しいと考えられてきた陸産貝類で長距離海流分散の可能性を示したことは、生物学の一般的な常識を覆す発見となりうる。