復活したタンパク質から推論されたプレカンブリア時代の生命のパラエオ温度傾向
Eric A Gaucher1, Sridhar Govindarajan, Omjoy K Ganesh
1Foundation for Applied Molecular Evolution, Gainesville, Florida 32601, USA.
Nature
|February 8, 2008
まとめ
地球上の古代生命は,漸進的な冷却の傾向を経験し,30億年以上にわたって30°C減少しました. 復活したタンパク質と地質学的データに基づいたこの発見は,生命の存在を明らかにしています.
科学分野:
- 進化生物学の進化生物学について
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- バイオジオケミストリー バイオジオケミストリー
背景:
- 微生物の生命は,少なくとも35億年前から地球上に存在し,多様な環境に住んでいます.
- 以前の研究では,復活したタンパク質を用いて古代の環境条件を推論し,初期の生命は暑い環境で繁栄していたことを示唆していた.
- 初期の生命が経験した温度変動を理解することは,地球の環境の歴史を再構築するために不可欠です.
研究 の 目的:
- 35億年前から50億年前まで,生命が住んでいた環境の古気温のトレンドを確立する.
- 変化する環境温度に対する古代生命の適応反応を調査する.
- 異なる科学分野における発見を検証する.
主な方法:
- 系統遺伝学的に分散した25以上の祖先の延長因子の復活.
- 古代の環境温度を推論するために,タンパク質の熱安定性の分析.
- パレオセアノグラフィのデータ,特に酸素同位体堆積とのクロス検証.
主要な成果:
- 35億から50億年前の地球の環境で約30°Cの漸進的な冷却傾向が推論された.
- 復活したタンパク質から派生した冷却の傾向は,統計的バイアスや系統遺伝的不確実性に対して強度を示した.
- 酸素同位体データから派生した古代海洋の独立した冷却傾向は,発見を裏付けました.
結論:
- 古代の生命は,数十億年にわたって地球環境の冷却に徐々に適応した.
- 自然科学と物理科学からのデータの収束は,推測された古気温の傾向を強化する.
- 進化の歴史は,環境の気温変動と密接に関連しています.
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