The birthplace of eukaryote in the Paleoproterozoic

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K14828
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 17050:Biogeosciences-related
• Research Institution: Okayama University of Science (2022); Tokyo Institute of Technology (2019-2021)
• Principal Investigator: Sato Tomohiko 岡山理科大学, 基盤教育センター, 准教授 (80714831)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 前期原生代 / 真核生物 / 炭素同位体 / 酸化還元 / ガボン

Outline of Final Research Achievements

In the Earth's history, the Paleoproterozoic Franceville Basins in Gabon is regarded as the birthplace of eukaryote. In order to clarify the temporal and spatial distribution of the biological evolution and the environmental changes in that period, this study conducted the geological fieldwork and inter-regional stratigraphic correlation of litho-facies, fossils, carbon and nitrogen isotopes, etc. In the Lastourville sub-basin, which was located in shallower ocean than the Franceville sub-basin, gradual changes in both carbon and nitrogen isotope ratios were identified. It suggests a gradual change into an anaerobic condition before the appearance of the eukaryotic fossils.

Free Research Field

地球史

Academic Significance and Societal Importance of the Research Achievements

真核生物の誕生は, 地球生命史における最も大きな進化のジャンプである. その進化がいつどのような環境で起きたのかを地質学・層序学的に解読することは, 生物進化の必要十分条件を解明する鍵として, 地球科学だけでなく生物学においても重要な意義を持つ. 本研究課題で得られた成果を下敷きに, ガボンにおける国際的な陸上掘削プロジェクトも動き始めており, 前期原生代の研究が今後さらに活発化していくと予想される.