How does the past constrain the present: a model for Oceanic island snail communities

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H02506
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: Tohoku University
• Principal Investigator: Chiba Satoshi 東北大学, 東北アジア研究センター, 教授 (10236812)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ニッチ保守性 / 系統的制約 / 進化傾向 / 群集構造 / 島嶼生物学

Outline of Final Research Achievements

The evolutionary history of the lineages of terrestrial molluscan communities distributed on islands and freshwater molluscan communities distributed in ancient lakes, mainly in East Asia including Japan, was comprehensively elucidated by molecular phylogeny. In addition to estimating the habitat use of the species in the modern community, fossil records were used to estimate past habitat use and compare it with phylogenetic relationships to infer trends in habitat shifts. The results showed that both terrestrial and freshwater molluscs from "Darwinian island" environments had characteristics that allow for flexible and rapid niche shifts, but significant levels of phylogenetic conservatism were detected as a whole. We conclude that these evolutionary constraints and niche conservatism have a significant influence on the distribution of ecological properties in the community.

Free Research Field

生態学

Academic Significance and Societal Importance of the Research Achievements

地球温暖化が生態系にどのような影響を及ぼすかを予想することは緊急の課題であり、社会的な要請が大きい。本成果は、ニッチ保守性の存在により、条件によっては生物種の性質は容易には変化した環境に適応できず絶滅することを示している。これは他の環境条件からの制約のため、温暖化は従来考えられているよりも大きな絶滅を生じる可能性が高いことを意味する。この影響の過小評価を推定した点は本研究の大きな意義である。