歯の進化的起源は,化石ののある脊椎動物からの証拠から分離しています
Moya Meredith Smith1, Zerina Johanson
1Craniofacial Development, Dental Institute, King's College London, Guy's Campus, London Bridge, London SE1 9RT, UK. moya.smith@kcl.ac.uk
Science (New York, N.Y.)
|February 22, 2003
まとめ
以前は歯がないと考えられていたプラコダームと呼ばれる化石の魚は,歯の列を持っていた. これらのプラコダーマの歯は,他のの脊椎動物と同じように発達し,少なくとも2回,歯がコンバージェントに進化したことを示唆しています.
科学分野:
- パレオントロジー・パレオントロジー
- 脊椎動物の進化について
- 発達生物学 発達生物学とは
背景:
- プラコドーム類 (Placodermi類) は,絶滅した基礎の脊椎動物である.
- 歯は,一般的にプラコダームに存在しないと考えられ,その起源はの進化後のものです.
- 歯の遺伝学的な起源は,のある脊椎動物の重要な研究分野であり続けています.
研究 の 目的:
- 歯の存在と性質を,派生性プラコダーム,特にアルトロダイアで調査する.
- プラコダーマの歯が他のグナトストーム (状の脊椎動物) の歯と類似した特徴を示すかどうかを判断する.
- 歯を持つ脊椎動物における歯の進化史を再評価する.
主な方法:
- 派生プラコダーム (arthrodires) の化石標本の分析.
- 歯の形態学と組織学的構造の顕微鏡検査.
- 発達と組成の特徴を現存するのある脊椎動物と比較.
主要な成果:
- 派生プラコダーム (arthrodires) の歯列の発見.
- この新たに確認された歯は,グナトストーム型の歯骨で構成されています.
- プラコダームの歯は,他のを持つ脊椎動物の歯と同様に発達し,調節されます.
結論:
- 派生プラコダームの歯の存在は,以前の仮定に異議を唱える.
- プラコダームの歯の発達は,少なくとも2回,歯の収束進化を示唆しています.
- この発見は,初期のを持つ脊椎動物の進化と歯の起源についての私たちの理解に影響を与えます.
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