穆氏擬態的優勢斑紋演化的分子生物學機制
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| photo from The magic of life butterfly house |
標題：Molecular mechanisms of dominance evolution in Müllerian mimicry.
摘要
Natural selection acting on dominance between adaptive alleles at polymorphic loci can be sufficiently strong for dominance to evolve. However, the molecular mechanisms underlying such evolution are generally unknown. Here, using Müllerian mimicry as a case-study for adaptive morphological variation, we present a theoretical analysis of the invasion of dominance modifiers altering gene expression through different molecular mechanisms. Toxic species involved in Müllerian mimicry exhibit warning coloration, and converge morphologically with other toxic species of the local community, due to positive frequency-dependent selection acting on these colorations. Polymorphism in warning coloration may be maintained by migration–selection balance with fine scale spatial heterogeneity. We modeled a dominance modifier locus altering the expression of the warning coloration locus, targeting one or several alleles, acting in cis or trans, and either enhancing or repressing expression. We confirmed that dominance could evolve when balanced polymorphism was maintained at the color locus. Dominance evolution could result from modifiers enhancing one allele specifically, irrespective of their linkage with the targeted locus. Nonspecific enhancers could also persist in populations, at frequencies tightly depending on their linkage with the targeted locus. Altogether, our results identify which mechanisms of expression alteration could lead to dominance evolution in polymorphic mimicry.
根據很多對於擬態的觀測與研究結果，無庸置疑的這是一個天擇的結果，但科學家無論如何觀測，從野外的族群到細胞裡的基因體，都只能觀測到這些結果，與推測可能的原因，對於天擇實際上透過什麼樣的「工具」來留下有優勢的斑紋，至今仍然是個很大的謎團。
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總之，這篇實在太抽象了，有興趣或有需要的朋友請自行詳細研讀吧。
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