Why do species exist? Insights from sexuals and asexuals
Why do species exist? Insights from sexuals and asexuals
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DOI：
10.1078/0944-2006-00130
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发表时间：
2003-01-01
期刊：
影响因子：
2
通讯作者：
Herniou, E
中科院分区：
文献类型：
--
作者：
Barraclough, TG;Herniou, E
为什么生命会多样化为我们认为是物种的或多或少离散的实体？提出了两种主要解释：i）物种是适应不同生态位的结果，ii）物种是有性繁殖和生殖隔离的结果。案例研究组的系统发育研究可以深入了解物种形成的趋异选择和分离的相对重要性，但很难明确地推断物种形成的原因。讨论了来自 Cicindela 属的北美虎甲虫的例子。另一种方法是比较相关有性和无性类群之间的多样性，以推断两种解释的相对重要性。我们使用合并理论概述了不同情景下有性和无性谱系多样化的预期模式。有性生殖或无性生殖在更大程度上是否多样化取决于多样化各个阶段之间的平衡，特别是有性生殖对适应性进化速率的影响。轮虫提供了一个独特的系统来测试这些想法，允许比较有性（蛭形）和无性（单性）进化枝的遗传和功能形态多样化的模式。
Why does life diversify into the more or less discrete entities we recognise as species? Two main explanations have been proposed: i) species are a consequence of adaptation to different ecological niches, ii) species are a consequence of sexual reproduction and reproductive isolation. Phylogenetic studies of case-study groups can provide insights into the relative importance of divergent selection and isolation for speciation, but it can be difficult to infer causes of speciation unambiguously. The example of North American tiger beetles from the genus Cicindela is discussed. An alternative approach is to compare diversification between related sexual and asexual taxa to infer the relative importance of the two explanations. We outline expected patterns of diversification in sexual and asexual lineages under different scenarios using coalescent theory. Whether sexuals or asexuals diversify to a greater extent depends on the balance among various stages of diversification, particularly on the effects of sexual reproduction on rates of adaptive evolution. Rotifers offer a unique system to test these ideas, allowing comparison of patterns of genetic and functional morphological diversification in sexual (bdelloid) and asexual (monogonont) clades.