コップの法則と北米の化石哺乳類の体質進化の動態
1Department of Paleobiology, Smithsonian Institution, MRC 121, Washington, DC 20560, USA.
Science (New York, N.Y.)
|May 23, 1998
まとめ
北米の化石哺乳類は,時間とともに系統内の体サイズを増やす傾向を示し,Copeをサポートしています.
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
- 哺乳類の進化について
背景:
- コップの法則は,進化の過程で哺乳類の体積が増加する一般的な傾向を記述しています.
- 以前の研究では,この傾向が真の進化パターンなのか,サンプリングバイアスの結果なのかが議論されてきた.
- 大きさの進化を理解することは,過去の生態系と進化のダイナミクスを再構築するために不可欠です.
研究 の 目的:
- 北米の化石哺乳類における体質進化の傾向を調査する.
- 体の大きさの増加が系統内で起こるのか,それとも他の要因によるのかを判断する.
- 体のサイズと観察された進化パターンとの関係を評価する.
主な方法:
- 北米の1534種の化石哺乳類の体重推定を分析した.
- 系統内効果を特定するために,属内の進化的傾向を調べた.
- ケノゾーイク全体で観察された進化パターンの体サイズの影響を評価した.
主要な成果:
- 新しい化石哺乳類の種は,同じ属の古い種よりも平均して9.1%大きい.
- この系統内の大きさの増加はケノゾーイク全体で一貫しており,コップの法則を説明しています.
- この効果は,より大きな哺乳類ではより顕著で,より小さな哺乳類では最小です.
結論:
- この研究は,北米の化石哺乳類の体質の系統内での持続的な増加を確認しています.
- このパターンは,ケノゾーイクにおける哺乳類の平均体長の漸進的な増加を説明する.
- 観察されたサイズ変動は,哺乳類のサイズ進化のいくつかの側面を説明するのに役立ちますが,すべてではありません.
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