花の色アレルに対する受粉媒介による選択は,強化を促す
Robin Hopkins1, Mark D Rausher
1Department of Biology, Duke University, Durham, NC 27708, USA. robin.hopkins@duke.edu
まとめ
選択の強化は,種間の生殖障壁を強化する. Phlox drummondiiでは,Phlox cuspidataとのハイブリッド化が少ない受粉者の行動により,強い色素が進化した.
科学分野:
- 進化生物学の進化生物学について
- 生物学的特異性 生物学的特異性
- 植物科学 植物科学について
背景:
- 強化は,異なった種間の生殖的孤立の進化を駆動する.
- ハイブリッドフィットネスの低下は,種間の交配を防ぐ特性の選択を引き起こす可能性があります.
- 強化メカニズムを理解することは,種種の理解に極めて重要です.
研究 の 目的:
- 自然環境における選択の強化の強さを定量化するために.
- 補強における受粉者の行動の役割を調査する.
- 種の多様化中に選択中の特徴を特定するために.
主な方法:
- 共同庭園のフィールド実験が行われました.
- Phlox drummondiiの色素濃度のアレル選択は定量化されました.
- 授粉者の移動パターンは,植物の色素化とPhlox cuspidataとの共感に関連して分析されました.
主要な成果:
- 強い選択により,フォロックス・ドラムモンディ (Phlox drummondii) のピグメント濃度が高まり,フォロックス・クスピダータ (Phlox cuspidata) と共生している.
- Phlox cuspidata.のない地域では,この色素ロカスへの選択は存在しなかった.
- 植物色素化の影響を受けた非ランダムな受粉者移動は,強化選択を生成するメカニズムとして特定されました.
結論:
- 選択の強化は,生態学的相互作用によって駆動され,自然の中で効果的に機能することができます.
- 授粉者の行動は,種間の遺伝子フローを変更することによって,強化選択を媒介する上で重要な役割を果たします.
- Phlox drummondiiのピグメントは,受粉者の訪問に影響を及ぼす信号として作用し,ハイブリデーションを減少させます.
関連する概念動画
Frequency-dependent Selection
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
Types of Selection
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...
Incomplete Dominance
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.
Mate Choice
Mate choice—the decision about whom to mate with—is a type of natural selection, since animals must reproduce to pass down their genes. Mate choice is also called intersexual selection because the behavior occurs between the sexes.
Mutation, Gene Flow, and Genetic Drift
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
Epistasis
In addition to multiple alleles at the same locus influencing traits, numerous genes or alleles at different locations may interact and influence phenotypes in a phenomenon called epistasis. For example, rabbit fur can be black or brown depending on whether the animal is homozygous dominant or heterozygous at a TYRP1 locus. However, if the rabbit is also homozygous recessive at a locus on the tyrosinase gene (TYR), it will have an unshaded coat that appears white, regardless of its TYRP1...


