皮膚の色素化は,絶滅した海洋爬虫類の収束性メラニズムの証拠を提供します
Johan Lindgren1, Peter Sjövall2, Ryan M Carney3
1Department of Geology, Lund University, SE-223 62 Lund, Sweden.
Nature
|January 10, 2014
まとめ
カメ,モササウル,イクチオサウルを含む化石化した海洋爬虫類は,メラニン色素の直接的な化学的証拠を示しています. これは,絶滅した水生動物の温度調節とカモフラージュのための暗い色彩の収束進化を示唆しています.
科学分野:
- パレオントロジー・パレオントロジー
- バイオケミストリー バイオケミストリー
- 進化生物学の進化生物学について
背景:
- 適応性のある色付けは,動物の生存と繁殖に不可欠です.
- メラニンは様々な機能を持つ重要な色素ですが,その化石記録はほとんど理解されていません.
- 化石化したメラニンを特定することは困難であり,古代の色素の知識を制限しています.
研究 の 目的:
- 化石化した海洋爬虫類の皮膚におけるメラニンの直接的な化学的証拠を提供するため.
- 絶滅した海洋爬虫類の色彩を再現するために.
- 絶滅した水生四足類におけるメラニズムの進化的要因を調査する.
主な方法:
- レザーバックカメ,モササウル,イチオサウルからの化石化した軟組織の化学分析.
- 分子的に保存されたユーメラニンと化石化したメラノソームの識別.
- 現存する海洋生物との比較分析.
主要な成果:
- ユーメラニンの直接的な化学的証拠は,海洋爬虫類の3つのグループの化石化した皮膚で見つかりました.
- メラニンは,標本における化石化したメラノソームと関連していた.
- カウンターシェーディングとは対照的に,いくつかのイクチオサウルスは均等に暗かった.
結論:
- メラニンの色素は,化石化した皮膚で化学的に識別され,化石の色の研究を拡大することができます.
- 収束性メラニズムは,二次的な水生四足類の独立して進化した系統で発生した.
- 温度調節および/または暗号化は,おそらくこの収束メラニズムを駆動し,寒い環境の搾取を可能にしました.
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