ネオトロピカル熱帯雨林の木の種に富んだ属の急速な多様化
J E Richardson1, R T Pennington, T D Pennington
1Royal Botanic Garden Edinburgh, 20a Inverleith Row, Edinburgh EH3 5LR, UK.
Science (New York, N.Y.)
|September 22, 2001
まとめ
最近のDNAデータによると,熱帯の木属のインガは,過去1000万年の間に急速に多様化しました. この種の形成は,アンデス山脈の上昇やパナマの上昇などの主要な地質学的な出来事と一致しています.
科学分野:
- エコロジー エコロジー エコロジー
- 進化生物学の進化生物学について
- 遺伝学 遺伝学とは
背景:
- 熱帯の種の豊かさは,安定した気候における漸進的な蓄積,または地質的および気候の不安定性によって引き起こされる急速な種の発生という2つの主要な理論によって説明される.
- ネオトロピクス地域は,例外的な生物多様性を持っていますが,この豊かさの原動力,特に植物属については,依然として議論されています.
研究 の 目的:
- DNA配列データを用いて,種に富んだ新熱帯の木属インガの多様化パターンを調査する.
- 生物種の発生を第三期と四期期の地質と気候の変化に結びつける仮説を検証する.
主な方法:
- インガ属のDNA配列データの系統遺伝分析.
- 分子時計法を用いた種化時間の推定.
- 多様化率と主要な古地理的,古気候的出来事との相関関係.
主要な成果:
- DNA配列データは,インガ属の近年の多様化爆発を示しています.
- 種の形成は過去1000万年に集中し,かなりの数の種は過去200万年に発生した.
- この急速な種の発生は,アンデス山脈の上昇,パナマ半島の形成,四季期の氷河周期と相関しています.
結論:
- 長期の安定性ではなく,最近の地質学と気候の出来事が,おそらくインガの多様化を後押しした.
- インガは,急速に多様化している他の新熱帯の属のモデルとして機能し,熱帯の生物多様性に大きく貢献します.
- インガのような属の多様性を理解することは,ネオトロピカル種の豊かさの起源を理解するために不可欠です.
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