The birthplace of putative multicellular organisms in the Paleoproterozoic

• Project/Area Number: 16K17826
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Stratigraphy/Paleontology
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Sato Tomohiko 東京工業大学, 地球生命研究所, 研究員 (80714831)
• Research Collaborator: Edou-Minko Ambroise ガボン・マスク工科大学, Prof. ; Moussavou Mathieu ガボン・マスク工科大学, Prof.
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2016: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 前期原生代 / ガボン / 真核生物 / 層序 / 炭素同位体比 / 窒素同位体比 / 地球史 / 化石 / 堆積岩 / 炭素同位体 / 窒素同位体 / 原生代 / 多細胞生物 / 酸素 / 酸化還元

Outline of Final Research Achievements

This study conducted the geological fieldworks in Gabon, and investigated the detailed litho-, bio-, and chemo-stratigraphy of the Paleoproterozoic sedimentary basins that yields the putative oldest eukaryotic fossils. The depositional environment of the fossil horizons in the Franceville Basin was clarified to be relatively anaerobic. The local high-radiation setting by the uranium-concentrated bed possibly accelerated the evolution of eukaryotes. In the Lastoursville Basin, the continuous δ13Ccarb stratigraphy was newly established, and a negativeδ13Ccarb shift was identified across the fossil appearance. This negative shift may correspond to the terminal Lomagundi Excursion and suggests that the appearance of eukaryotes dramatically changed the global oceanic carbon cycle.

Academic Significance and Societal Importance of the Research Achievements

原核生物 (バクテリア, アーキア) から真核生物への進化は, 地球史における最も大きな進化の一つである. その進化が, いつどのような環境下で起きたのか明らかにするためには, 最古の真核生物化石が産する地層から当時の環境を解読することが不可欠である. 本研究で明らかにした, 局所的な高放射線場や, 地球規模の炭素循環変動と真核生物出現の関係は, 地球科学のみならず生物学において, 生物進化の必要十分条件を解明するための鍵となると期待される.

Research Products

• [Int'l Joint Research] マスク工科大学(ガボン)
• [Int'l Joint Research] マスク工科大学(ガボン)
• [Journal Article] Zircon geochronology of the Paleoproterozoic Magondi Supergroup in Zimbabwe: Age constraints to the Lomagundi-Jatuli event. (2019)
  • Author(s): Sawada, H., Mugandani, E., Sato, T., Sawaki, Y., Sakata, S., Isozaki, Y., Maruyama, S.
  • Journal Title: Terra Nova Volume: 31 Issue: 5 Pages: 438-444
  • DOI: 10.1111/ter.12407
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] 天然原子炉の地質と真核生物誕生 (2018)
  • Author(s): 澤木佑介、佐藤友彦、藤崎渉、上田修裕、浅沼尚、丸山茂徳
  • Journal Title: 地学雑誌 Volume: 印刷中
  • Peer Reviewed
• [Journal Article] Growth, Duplication and Lateral Mutual Compressive Deformation of Akouemma hemisphaeria on the Seafloor of Okondja Basin at 2.2 Ga (Gabon) (2017)
  • Author(s): Edou-Minko Ambroise、Moussavou Mathieu、Sato Tomohiko、Sawaki Yusuke、Ondo Simplice Ndong、Maire Richard、Fleury Guillaume、Mounguengui Michel Mbina、Kaestner Anders、Ortega Richard、Roudeau Stephane、Carmona Asuncion、Mvoubou Makaya、Moussavou Benjamin Musavu、Sasaki Osamu、Maruyama Shigenori
  • Journal Title: International Journal of Geosciences Volume: 08 Issue: 09 Pages: 1172-1191
  • DOI: 10.4236/ijg.2017.89067
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] New isotopic age data constrain the depositional age and accretionary history of the Neoproterozoic-Ordovician Mona Complex (Anglesey-Lleyn, Wales) (2017)
  • Author(s): H. Asanuma, W. Fujisaki, T. Sato, S. Sakata, Y. Sawaki, K. Aoki, Y. Okada, S. Maruyama, T. Hirata, T. Itaya, B.F. Windely
  • Journal Title: Tectonophysics Volume: 706-707 Pages: 164-195
  • DOI: 10.1016/j.tecto.2017.03.017
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Centimeter-wide worm-like fossils from the lowest Cambrian of South China (2017)
  • Author(s): Zhang Xingliang、Liu Wei、Isozaki Yukio、Sato Tomohiko
  • Journal Title: Scientific Reports Volume: 7 Issue: 1 Pages: 1-11
  • DOI: 10.1038/s41598-017-15089-y
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Chronological constraints on the Paleoproterozoic Francevillian Group in Gabon. (2017)
  • Author(s): Sawaki, Y., Moussavou, M., Sato, T., Suzuki, K., Ligna, C., Asanuma, H., Sakata, S., Obayashi, H., Hirata, T., Edou-Minko, A.,
  • Journal Title: Geoscience Frontiers Volume: 8 Issue: 2 Pages: 397-407
  • DOI: 10.1016/j.gsf.2016.10.001
  • NAID: 120006358790
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] An Akouemma hemisphaeria Organic Macrofossils Colony Hosting Biodiversity Assemblage on the Seafloor of Okondja Basin (Gabon) dated at 2.2 Ga (2017)
  • Author(s): Edou-Minko A., Moussavou M., Sato T., Tchikoundzi C., Sawaki Y., Ndong Ondo S., Ortega R., Maire R., Kaestner A., Mbina Mounguengui M., Roudeau S., Fleury G., Carmona A., de Parseval PH., Makaya Mvoubou., Musavu Moussavou B., Ogandaga Agondjo M., Sasaki O., Maruyama S.
  • Journal Title: Journal of Geology & Geophysics Volume: 6:281 Issue: 02 Pages: 1-21
  • DOI: 10.4172/2381-8719.1000281
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] ガボン前期原生代フランスヴィル層群の炭酸塩炭素同位体層序 (2019)
  • Author(s): 佐藤友彦, 澤木佑介, 浅沼尚, 上田修裕, 丸山茂徳
  • Organizer: 日本地球惑星科学連合大会
  • Invited
• [Presentation] Uranium ore through time: Did the natural nuclear reactor exist on the Hadean Earth? (2018)
  • Author(s): Sato, T.
  • Organizer: ELSI 7th International Symposium: Comparative Emergence
  • Int'l Joint Research
• [Presentation] ガボン・フランスヴィル堆積盆における大型化石出現前後の前期原生代有機炭素・窒素同位体層序 (2018)
  • Author(s): 佐藤友彦, 澤木佑介, 丸山茂徳
  • Organizer: 日本地球惑星科学連合大会
• [Presentation] Geotectonic history of ultra-reducing habitat of Hakuba OD1: 4 billion-year-old living fossils (2018)
  • Author(s): Sato, T.
  • Organizer: ELSI 6th International Symposium: Building bridges from Earth to Life
  • Int'l Joint Research
• [Presentation] Paleoproterozoic organic carbon and nitrogen isotopic stratigraphy across the appearance of macrofossils in the Francevillian Basins, Gabon (2017)
  • Author(s): Tomohiko Sato
  • Organizer: ELSI International Symposium
  • Place of Presentation: 東京, 東京工業大学
  • Year and Date: 2017-01-10
  • Int'l Joint Research
• [Presentation] Paleoproterozoic organic carbon and nitrogen isotopic stratigraphy across the appearance of macrofossils in the Francevillian Basins, Gabon (2017)
  • Author(s): Sato, T., Sawaki, Y., Saitoh, M., Matsui, Y., Maruyama, S., Bakakas, K., Ligna, C., Moussavou, M., Edou-Minko, A.
  • Organizer: The Geological Society of America Annual Meeting
  • Int'l Joint Research
• [Presentation] ガボンにおける前期原生代炭素同位体層序 (2017)
  • Author(s): 佐藤友彦, 澤木佑介,斎藤誠史, 松井洋平, 丸山茂徳
  • Organizer: 日本地質学会
• [Presentation] The Early Cambrian phosphorite deposition and the cradle of early skeletal animals (2017)
  • Author(s): Sato, T., Isozaki, Y., Zhang, X.
  • Organizer: IGCP 630 Annual Meeting (Permian-Triassic Climatic & Environmental Extremes and Biotic Response)
  • Int'l Joint Research
• [Presentation] ガボン・前期原生代フランスヴィル層群における生物多様性 (2017)
  • Author(s): 佐藤友彦, 澤木佑介, 丸山茂徳
  • Organizer: 日本地球惑星科学連合大会
• [Presentation] 付加体遠洋深海チャート中の鉄化学種に記録された古海洋酸化還元環境 (2016)
  • Author(s): 佐藤友彦
  • Organizer: 日本地質学会
  • Place of Presentation: 東京, 日本大学文理学部キャンパス
  • Year and Date: 2016-09-12
  • Invited
• [Presentation] ガボン・フランスヴィル盆地における前期原生代有機炭素・窒素同位体層序：大型化石出現後の嫌気的環境 (2016)
  • Author(s): 佐藤友彦, 澤木佑介, 丸山茂徳, 斎藤誠史, 松井洋平
  • Organizer: 日本地質学会
  • Place of Presentation: 東京, 日本大学文理学部キャンパス
  • Year and Date: 2016-09-12
• [Presentation] カンブリア爆発：進化のホットスポット南中国 (2016)
  • Author(s): 佐藤友彦, 澤木佑介
  • Organizer: 日本進化学会
  • Place of Presentation: 東京, 東京工業大学
  • Year and Date: 2016-08-25
• [Presentation] ガボン南東部における前期原生代（2.1 Ga）堆積盆地の造構場：初期大型生物の進化のホットスポット (2016)
  • Author(s): 佐藤友彦, 澤木佑介, 丸山茂徳
  • Organizer: 日本地球惑星科学連合大会
  • Place of Presentation: 千葉, 幕張メッセ
  • Year and Date: 2016-05-25
• [Book] リンの事典 (2017)
  • Author(s): 大竹久夫 編 （佐藤友彦 部分執筆）
  • Total Pages: 360
  • Publisher: 朝倉書店
  • ISBN: 9784254141047
• [Remarks] Supplementary Informations
  • URL: https://sites.google.com/site/tomopikosato/supplement