アウストラロピテクス・アファレンシスの足の4番目の四足足骨とアーチを完成させた
Carol V Ward1, William H Kimbel, Donald C Johanson
1Department of Pathology and Anatomical Sciences, M263 Medical Sciences Building, University of Missouri, Columbia, MO 65212, USA. wardcv@missouri.edu
Science (New York, N.Y.)
|February 12, 2011
まとめ
第4次足頭骨から採取した化石の証拠は,アウストラロピテクス・アファレンシスが人間のような足の弓を持っていたことを示している. この発見は,この初期のヒトの祖先が地上の双足動物であったという仮説を裏付けている.
科学分野:
- 古人類学は,古人類学である.
- 人間の進化 人類の進化
- 機能的形態学 機能的形態学
背景:
- 人間の二足の進化は,特に足の重要な解剖学的変化によって特徴付けられています.
- 足の弓の発達は,効率的な地上移動に不可欠であり,衝撃吸収と硬い推進レバーを提供します.
- アウストラロピテクス・アファレンシス (Australopithecus afarensis) のような初期のホミニンにアーチが存在することは,現在進行中の議論の対象となっている.
研究 の 目的:
- Australopithecus afarensis.の足のアーチの存在を調査するために.
- A. afarensisの足の構造が,陸上の双脚性のために適応されたかどうかを判断するために.
主な方法:
- エチオピア・ハダールで発見されたA. afarensisの4つ目の四足足骨の分析.
- 骨の歪み,関節末端の向き,およびタールス面形態の検査.
- 化石形態の比較と,現代のヒトと類人猿の足の機能的相関.
主要な成果:
- 4番目の足元は,頭部と足底の相対的な扭曲を示し,横軸のアーチを示しています.
- 骨の近辺と遠端の方向性は,縦軸のアーチの存在を示唆しています.
- ベースとターサルの側面の形状は,猿のようなミドルターサルの断裂がないことを示しています.
結論:
- A. afarensisの足は,この四足骨をベースに,機能的には現代のヒトの足と似ていた.
- これらの発見は,A. afarensisが固有の陸上の二足動物であることを強く支持しています.
- この証拠は,初期のヒト類の移動と進化の適応に関する私たちの理解を洗練します.
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