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生物群の起源に関する進化的および保存的制約:エウテリアン哺乳類の分岐時間
M Foote1, J P Hunter, C M Janis
1Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA. mfoote@midway.uchicago.edu
Science (New York, N.Y.)
|February 26, 1999
まとめ
分子時計の推定は,種の古代の起源を示唆しますが,数学モデルは,化石記録がこれらの初期の分岐時間を支持するかどうかを評価するのに役立ちます. ユーテリアン哺乳類については,化石記録は,その真の進化的放射線起源を反映している可能性が高い.
科学分野:
- 進化生物学の進化生物学について
- パレオントロジー・パレオントロジー
- バイオマテマティクス バイオマテマティクス
背景:
- 急速に多様化しているいくつかの種の分子時計の推定は,その化石記録よりもはるかに古い逸脱時間を示唆しています.
- 分子ダイバージェンスの時間を化石の証拠と調和させることは,進化史を理解するために極めて重要です.
研究 の 目的:
- 推論された進化史と一致する最大化石保存率を推定するための数学的モデルを開発する.
- 化石記録データに基づいて,急速に放射する分類種の早期の分岐時間の妥当性を評価する.
主な方法:
- 種の発生,絶滅,持続をシミュレートするために,分岐進化の数学モデルを利用した.
- 進化の歴史が欠けていたと仮定されたことを説明するために必要な最大の化石保存率を計算した.
- モデルを適用して,エウテリアン哺乳類の分岐時間を推定した.
主要な成果:
- この研究は,分子時計の推定値と化石記録の間の不一致を説明できる起源,絶滅,保存率の範囲を決定した.
- ユーテリアン哺乳類については,結果により,それらの主要な系統は,いくつかの分子時計の推定値よりも,最も古い化石記録に近い起源を持つ可能性が高いことが示されています.
結論:
- 古代の分岐時間の妥当性は,種の発生,絶滅,化石の保存の現実的な速度に依存しています.
- ユーテリアン哺乳類の化石記録は,それらの主要な多様化イベントの比較的信頼できる指標であるようです.
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