生命の歴史における多様化と絶滅

M J Benton¹

¹Department of Geology, University of Bristol, United Kingdom.

Science (New York, N.Y.)

|April 7, 1995

まとめ

人生人生人生人生人生

科学分野:

パレオントロジー・パレオントロジー
進化生物学の進化生物学について
地質学の歴史地質学史

背景:

化石記録は,プレカンブリア時代以来,海洋と大陸の生物の多様性が著しく増加したことを明らかにしています.
この進化の拡大は,地球の歴史を通じて,いくつかの大規模な大量絶滅の出来事によって断続されています.

研究の目的:

地質学的時間における生物多様性と大量絶滅のパターンを分析する.
大量絶滅のイベントの潜在的な周期性を調査する.

主な方法:

微生物,藻類,真菌,原生類,植物,動物を含む化石記録の分析.
海洋および大陸の生態系における絶滅イベントのタイミングと頻度の検討.

主要な成果:

海洋生物と陸生生物の両方を含む地球規模の生物多様性は,プレカンブリア期以来指数関数的に増加しています.
過去2億5000万年の間に7つの大規模な大量絶滅が起こり,様々な生命形態に影響を及ぼしました.
これらの大量絶滅のイベントの定期的な周期性を支持する証拠は見つかりませんでしたが,その間隔は2千万年から6千万年でした.

結論:

地球の歴史は,生物多様性の増加が特徴であり,重要な,周期的でない大量絶滅が間接しています.
これらの絶滅の出来事を理解することは,生命の進化の軌道を理解するために極めて重要です.

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