生命と地球の大気圏の進化
James F Kasting1, Janet L Siefert
1Department of Geosciences, 443 Deike, The Pennsylvania State University, University Park, PA 16802, USA. kasting@essc.psu.edu
Science (New York, N.Y.)
|May 11, 2002
まとめ
シアノバクテリアや藻類のような微生物は光合成を行い,酸素を生産し,窒素を固定します. 初期の無酸素細菌は,初期の地球を調節したのかもしれません.
科学分野:
- 天体生物学と進化生物学について
- バイオジオケミカルサイクル
- 微生物生態学 微生物生態学とは
背景:
- 光合成は,エネルギーと酸素の生産のために光を採集するプロセスであり,古代シアノバクテリアから生まれた陸上の植物の重要な特徴です.
- シアノバクテリアと顕微鏡藻類は,今日,大気中の酸素と海洋の固定窒素に不可欠です.
- 初期の地球の大気と気候は,酸素化イベントの前に微生物の生命によって著しく影響を受けました.
研究 の 目的:
- 地球の大気の進化における微生物の重要な役割を調査する.
- 気候調節に対する初期の微生物生命の貢献を理解する.
- 生物の進化と大気の変化の相互関係を強調する.
主な方法:
- 光合成および無酸素微生物の進化史のレビュー.
- 微生物の活動によって引き起こされる生地化学的過程の分析.
- 初期の地球の環境条件と微生物の影響の再構築.
主要な成果:
- シアノバクテリアの光合成能力は植物に移され,陸上の生態系を形成した.
- 海洋の微生物は,世界の酸素と窒素の循環に不可欠です.
- アナーロビック細菌はおそらくメタンを生成し,初期の地球で温暖な気候を維持した.
結論:
- 地球の大気の進化は,その生物の進化と密接に関連しています.
- 酸素光合成からメタノゲネシスまでの微生物の革新は,惑星の居住可能性を深く形作っています.
- 古代の微生物の役割を理解することは,地球システムの進化を理解する鍵です.
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Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...