鳥はペエドモルフの恐竜の頭蓋骨を持っている
Bhart-Anjan S Bhullar1, Jesús Marugán-Lobón, Fernando Racimo
1Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA. bhartanjan.bhullar@gmail.com
Nature
|June 23, 2012
まとめ
子孫が幼い祖先に似ている発達過程であるペエドモルフォシスは,鳥の起源における主要な進化のステップを説明します. この研究では,恐竜と鳥の頭蓋骨を分析して,鳥類の進化における重要なペドモルフィック現象を明らかにした.
科学分野:
- 進化的発達生物学 進化的発達生物学
- パレオントロジー・パレオントロジー
- 比較解剖学の比較解剖学について
背景:
- 進化と発達の相互作用は,進化論の中心にある.
- ヘテロクロニー,つまり発達タイミングの変化は,脊椎動物の進化にとって極めて重要です.
- 鳥は,飛行と多様なライフスタイルに適応したユニークな頭蓋骨の解剖学を示しています.
研究 の 目的:
- 鳥類の進化的起源におけるヘテロクロニー,特にペイドモルフォシスの役割を調査する.
- セロポッド恐竜,アウトグループ,鳥の頭蓋骨の発達を分析する.
主な方法:
- 発達,ネオントロジー,そして古生物学のデータを統合した幾何学的形態測定法.
- セロポッド恐竜のオントゲニーおよび関連する分類における頭蓋骨のランドマークの変動性の分析.
- オントジェネティック段階と系統遺伝子のグループにおける頭蓋骨形態の比較分析.
主要な成果:
- オントゲニーと系統遺伝の変化は,頭蓋骨のランドマークデータにおける変性の最初の2次元によって捉えられた.
- 基礎的なeumaniraptoransとavialansは,胚性アーコサウルスとクラスタリングされ,ペエドモルフォシスを示しています.
- 鳥の進化において,少なくとも4つのペエドモルフィックエピソードが特定され,その中の一つはの局所的な変形であった.
結論:
- パエドモルフォシスは,鳥の起源における主要な進化的移行において重要な役割を果たしました.
- 鳥の目や脳の領域がペエドモルフォシスによって拡大することは,哺乳類の嗅覚系の進化に類似している.
- この研究は,進化的移行と適応的特徴の起源におけるヘテロクロニーを調査するためのモデルを提供します.
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