頻度依存は,在住者よりも稀な移民を好むことで,異なった進化を制限する

Daniel I Bolnick¹, William E Stutz¹

¹Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712, USA.

Nature

|June 1, 2017

まとめ

ネガティブ周波数依存選択は,一般住民よりも稀な移民を好み,潜在的に異なる選択を妨げ,人口の違いに影響を与える. これは種化要因に関する伝統的な見解に異議を唱えるものです

科学分野:

進化生物学
エコロジー
集団遺伝学

背景:

自然淘汰の2つの形態である分離性淘汰と負の頻度依存性淘汰は生物多様性を駆り立てます
これらの力は異なる空間スケールで作用し,その相互作用はよく理解されていません.

研究の目的:

集団の多様性に対する偏差と負の周波数依存選択の同時効果を調査する.
移民と居住者の成功に周波数依存の選択がどのように影響するかを決定する.

主な方法:

湖と川の生態型を相互に移植する
自然生息地における居住者と移民の比率の操作
メジャー・ヒストコンパティビリティ・コンプレックス (MHC) の遺伝子型希少性を含む生存率と寄生虫の負荷の分析.

主要な成果:

希少なエコタイプがより高い生存率を示した.
希少なメジャー・ヒストコンパティビリティ・コンプレックス (MHC) クラスIIbの遺伝子型を持つ個体では,寄生虫感染が減少した.
寄生虫の増殖傾向は異なった選択の兆候を示唆している.

結論:

ネガティブな頻度依存選択は,希少な移民を好み,移住効果を潜在的に増幅し,異なる選択を減らすことができます.
このメカニズムは,生態学的相互作用が進化の分岐と種種化にどのように影響するかについてより複雑な視点を提供します.

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