大量絶滅後の海 snails の間で競争が減り,食生活が変化した

Gregory P Dietl¹, Gregory S Herbert, Geerat J Vermeij

¹Center for Marine Science, University of North Carolina, Wilmington, NC 28409, USA.

Science (New York, N.Y.)

|December 25, 2004

まとめ

大量絶滅の出来事は,種間の競争のダイナミクスを再構築した. 絶滅後,捕食スナイルは資源の競争が激しくなくなり,獲物を攻撃する戦略が変わった.

科学分野:

パレオントロジー・パレオントロジー
マリン・バイオロジーマリン・バイオロジー
進化の生態学進化の生態学とは

背景:

大量絶滅は,種の相互作用や進化の軌道を大きく変えてしまう.
絶滅後の生態学的動態を理解することは,進化論の研究にとって極めて重要です.

研究の目的:

プレオ・プレイストセンの大量絶滅前と後の海洋生物の相互競争の変化を調査する.
殺人カタツムリの捕食行動が資源競争をどのように反映しているかを分析する.

主な方法:

プリオセーンとプレイストセーン/最近の時代の双valve貝殻の化石化した捕食者の痕跡 (掘削パターン) の分析.
既存のムリキッド・スナイルを用いた実験研究で,掘削行動と競争の強さを相関させる.

主要な成果:

殺人スナイルは,プレオ・プレイストセンの絶滅前 (エッジ・ウォール・ドリリング) と後 (ウォール・ドリリングのみ) において,異なる捕食戦略を示した.
実験的証拠は,エッジ・ドリリングの行動は,激しい資源競争によって誘発されると示唆しています.

結論:

西大西洋におけるプレオ・プレイストセンの大量絶滅は,ムリキッド・スナイル間の種間競争の減少につながった.
捕食者の行動の変化は,絶滅の後に変化した競争的景観を反映しています.

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