Reevaluating claims of ecological speciation in Halichoeres bivittatus

Allopatry has traditionally been viewed as the primary driver of speciation in marine taxa, but the geography of the marine environment and the larval dispersal capabilities of many marine organisms render this view somewhat questionable. In marine fishes, one of the earliest and most highly cited empirical examples of ecological speciation with gene flow is the slippery dick wrasse, Halichoeres bivittatus. Evidence for this cryptic or incipient speciation event was primarily in the form of a deep divergence in a single mitochondrial locus between the northern and southern Gulf of Mexico, combined with a finding that these two haplotypes were associated with different habitat types (“tropical” vs. “subtropical”) in the Florida Keys and Bermuda, where they overlap. Here we examine habitat assortment in the Florida Keys using a broader sampling of populations and habitat types than were available for the original study. We find no evidence to support the claim that haplotype frequencies d...

异域物种形成（Allopatry）传统上被视为海洋类群物种形成的主要驱动因素，但海洋环境的地理特征与多数海洋生物的幼体扩散能力，使得这一观点颇受质疑。在海洋鱼类中，兼具基因流（gene flow）的生态物种形成（ecological speciation）研究最早且被引率最高的实证案例之一，便是双线海猪鱼（*Halichoeres bivittatus*，俗称slippery dick wrasse）。该项隐蔽或初期物种形成事件的相关证据，主要来源于墨西哥湾南北海域间单个线粒体位点（mitochondrial locus）上的显著分化，以及一项发现：在佛罗里达礁岛群与百慕大的重叠分布区内，这两种单倍型（haplotype）分别与"热带"与"亚热带"两类生境相关联。本研究针对佛罗里达礁岛群的生境分异情况展开分析，相较于原始研究，我们采用了覆盖更广的种群与生境类型采样方案。结果未发现任何证据支持单倍型频率……