Habitat avoidance: Overlooking an important aspect of host-specific mating and sympatric speciation?
Habitat avoidance: Overlooking an important aspect of host-specific mating and sympatric speciation?
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DOI：
10.1111/j.0014-3820.2005.tb01804.x
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发表时间：
2005-07-01
期刊：
影响因子：
3.3
通讯作者：
Feder, JL
中科院分区：
文献类型：
--
作者：
Forbes, AA;Fisher, J;Feder, JL
了解物种形成需要辨别基因流动的生殖障碍是如何在以前的杂交种群之间进化的。植食昆虫的同域物种形成模型假设，由于昆虫转移和生态适应新的寄主植物，生殖隔离可以在没有地理隔离的情况下进化。促进同域分化的一个重要适应是宿主特异性交配。当生物在首选栖息地交配时，一个积极的分类交配系统就建立起来了，促进了同域分化。寄主保真度模型通常假设寄主选择是由赋予对不同植物物种积极偏好的等位基因的总体效应决定的。但避免非原生植物的负效应基因也可能影响寄主的利用。先前的研究表明，寄生于苹果和山楂的pomonella Rhagoletis蝇类利用果实表面释放的挥发性化合物作为识别和区分寄主植物的关键化学感觉线索。在这里，我们报告了田间试验的结果，表明除了喜欢其出生果实的气味外，苹果和山楂蝇，以及它们未描述的姐妹物种，寄生于开花茱萸（山茱萸），也避免非出生果实的气味。我们讨论了同域物种形成的进化动力学和遗传学的非出生果回避的含义。我们的研究结果揭示了栖息地回避作为潜在的交配后和合子前基因流动障碍的作用。
Understanding speciation requires discerning how reproductive barriers to gene flow evolve between previously interbreeding populations. Models of sympatric speciation for phytophagous insects posit that reproductive isolation can evolve in the absence of geographic isolation as a consequence of an insect shifting and ecologically adapting to a new host plant. One important adaptation contributing to sympatric differentiation is host-specific mating. When organisms mate in preferred habitats, a system of positive assortative mating is established that facilitates sympatric divergence. Models of host fidelity generally assume that host choice is determined by the aggregate effect of alleles imparting positive preferences for different plant species. But negative effect genes for avoiding nonnatal plants may also influence host use. Previous studies have shown that apple and hawthorn-infesting races of Rhagoletis pomonella flies use volatile compounds emitted from the surface of fruit as key chemosensory cues to recognize and distinguish between their host plants. Here, we report results from field trials indicating that in addition to preferring the odor of their natal fruit, apple and hawthorn flies, and their undescribed sister species infesting flowering dogwood (Cornus florida), also avoid the odors of nonnatal fruit. We discuss the implications of nonnatal fruit avoidance for the evolutionary dynamics and genetics of sympatric speciation. Our findings reveal an underappreciated role for habitat avoidance as a potential postmating, as well as prezygotic, barrier to gene flow.