普遍的な共通の祖先の理論の正式なテスト
1Department of Biochemistry, Brandeis University, Waltham, Massachusetts 01778, USA. dtheobald@brandeis.edu
Nature
|May 14, 2010
まとめ
この研究は,地球上のすべての生命が単一の起源を共有していることを確認する,普遍的な共通の祖先 (UCA) の最初の正式な定量的なテストを提供します. 保存されたタンパク質の統計的分析は,水平の遺伝子転送であっても,圧倒的にUCAをサポートしています.
科学分野:
- 進化生物学の進化生物学について
- 遺伝学 遺伝学とは
- フィロジェネティクス フィルジェネティクス
背景:
- 普遍的な共通の祖先 (UCA) は,進化論の基本的概念であり,すべての生命が単一の祖先種から降ってきたことを示唆しています.
- 過去のUCAの証拠は,主に"局所的"であり,現代の系統遺伝学および確率的方法との統合が欠けていました.
- 生命の初期に横断的に広がる遺伝子の移転に関する懸念は,すべての生命のモノフィルの存在を脅かしている.
研究 の 目的:
- 普遍的な共通の祖先 (UCA) の最初の公式で定量的なテストを実施する.
- 配列の類似性を想定せずにUCAを評価するには,直接的な遺伝的親族関係が示唆されます.
- 既知のすべての生命の単一体を統計的に評価する.
主な方法:
- モデル選択理論を分子系統学に応用した.
- オートロゴスとして提案された,至るところに存在する保存されたタンパク質のセットに焦点を当てた.
- 主要な分類群の独立した祖先の複数のモデルに対してUCAモデルを比較した.
主要な成果:
- モデル選択テストは,普遍的な共通の祖先モデルを圧倒的に支持しました.
- このサポートは,水平遺伝子転送と共生融合イベントを考慮したにもかかわらず,堅調に留まっていました.
- この発見は,既知のすべての陸上の生命の単一性であることの強力な統計的証拠を提供します.
結論:
- この研究は,普遍的な共通の祖先の最初の厳格な統計的検証を提供します.
- すべての生命の単一体は,水平遺伝子の移転のような複雑さに関係なく,強く支持されています.
- この研究は,UCAを現代の進化論の中心的,経験的に検証された柱として強化しています.
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