Biology Department, Duke University, Durham, NC 27708, USA.
Heredity (Edinb). 2009 Dec;103(6):439-44. doi: 10.1038/hdy.2009.151.
Over the past decade, many studies documented high genetic divergence between closely related species in genomic regions experiencing restricted recombination in hybrids, such as within chromosomal rearrangements or areas adjacent to centromeres. Such regions have been called 'islands of speciation' because of their presumed role in maintaining the integrity of species despite gene flow elsewhere in the genome. Here, we review alternative explanations for such patterns. Segregation of ancestral variation or artifacts of nucleotide diversity within species can readily lead to higher F(ST) in regions of restricted recombination than other parts of the genome, even in the complete absence of interspecies gene flow, and thereby cause investigators to erroneously conclude that islands of speciation exist. We conclude by discussing strengths and weaknesses of various means for testing the role of restricted recombination in maintaining species.
在过去的十年中，许多研究记录了在杂交中经历限制重组的基因组区域中密切相关的物种之间的高遗传分歧，例如在染色体重排或着丝粒附近的区域。由于这些区域在基因组的其他地方存在基因流的情况下，仍然假定对物种的完整性具有重要作用，因此这些区域被称为“物种形成的岛屿”。在这里，我们回顾了对这种模式的替代解释。祖先变异的分离或物种内核苷酸多样性的假象很容易导致限制重组区域的 F(ST)高于基因组的其他部分，即使在完全没有种间基因流的情况下也是如此，从而导致研究人员错误地得出存在物种形成的岛屿的结论。最后，我们讨论了各种检验限制重组在维持物种中的作用的方法的优缺点。
