初期の馬の進化は,パレオセーヌ・エオセーヌ熱極の気候変化によって引き起こされた
Ross Secord1, Jonathan I Bloch, Stephen G B Chester
1Department of Earth and Atmospheric Sciences, University of Nebraska, Lincoln, NE 68588, USA. rsecord2@unl.edu
Science (New York, N.Y.)
|February 25, 2012
まとめ
哺乳類は,気温上昇とCO2濃度の上昇により,旧紀・新紀熱最大期 (PETM) の間,急速に縮小した. 気候の回復に伴い,体の大きさは著しく回復し,将来の地球温暖化の影響についての洞察を提供しました.
科学分野:
- パレオントロジー・パレオントロジー
- 気候科学 気候科学
- 哺乳動物生態学 哺乳動物生態学
背景:
- 体の大きさは哺乳類の生理学と生態学的役割の重要な要因です.
- 以前の研究では,ペレオセン・エオセン熱最大期 (PETM) における哺乳類の矮小化が示唆されていたが,正確なタイミングと気候の相関は不明であった.
研究 の 目的:
- PETMの間,大陸の気候変化と馬の体格との関係を調査する.
- パレオセーヌ・エオセーヌ熱極限気候のダイナミクスに関連して,体サイズ変化のタイミングと大きさを決定する.
主な方法:
- 高解像度の大陸気候記録の分析.
- PETMの期間中に馬の体格の変化を調べる.
- 哺乳類の歯から採取した酸素同位体を用いて古気温の推論.
主要な成果:
- PETMの初期約13万年に,馬の体積が~30%方向的に減少した.
- PETMの回復段階では ~76%の身体サイズ増加が顕著に観察されました.
- 哺乳類の体格の変化は,推論された温度と潜在的に高い大気中のCO2レベルとの負の相関を示した.
結論:
- 温度上昇と二酸化炭素濃度の上昇は,PETMの間,哺乳類の体の大きさの変動を大きく引き起こす可能性が高い.
- これらの過去の反応を理解することは,将来の気候変動と地球温暖化への哺乳類の進化的適応を予測するための枠組みを提供します.
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