Data from: Dispersal capacity predicts both population genetic structure and species richness in reef fishes

Dispersal is a fundamental species characteristic that should directly affect both rates of gene flow among spatially distributed populations and opportunities for speciation. Yet no single trait associated with dispersal has been demonstrated to affect both micro- and macroevolutionary patterns of diversity across a diverse biological assemblage. Here, we examine patterns of genetic differentiation and species richness in reef fishes, an assemblage of over 7,000 species comprising approximately one-third of the extant bony fishes and over one-tenth of living vertebrates. In reef fishes, dispersal occurs primarily during a planktonic larval stage. There are two major reproductive and parental investment syndromes among reef fishes, and the differences between them have implications for dispersal: (1) benthic guarding fishes lay negatively buoyant eggs, typically guarded by the male parent, and from these eggs hatch large, strongly swimming larvae; in contrast, (2) pelagic spawning fishes release small floating eggs directly into the water column, which drift unprotected before small weakly swimming larvae hatch. Using phylogenetic comparative methods, we show that benthic guarders have significantly greater population structure than pelagic spawners and additionally that taxonomic families of benthic guarders are more species rich than families of pelagic spawners. Our findings provide a compelling case for the continuity between micro- and macroevolutionary processes of biological diversification and underscore the importance of dispersal-related traits in influencing the mode and tempo of evolution.

扩散（dispersal）是物种的核心特征之一，其直接影响空间分布种群间的基因流速率，以及物种形成的潜在契机。然而，在多样的生物类群中，尚未有任何与扩散相关的单一性状被证实，能够同时影响多样性的微进化与宏进化格局。
本研究聚焦礁栖鱼类（reef fishes）的遗传分化格局与物种丰富度特征。礁栖鱼类类群包含逾7000个物种，约占现生硬骨鱼的三分之一、现生脊椎动物的十分之一以上。在礁栖鱼类中，扩散主要发生于浮游幼虫阶段。
礁栖鱼类存在两种主要的繁殖与育幼投资模式，二者的差异对扩散过程具有显著影响：其一为底栖护卵鱼类，该类群产出沉性卵，通常由雄性亲本守护，幼体孵化后体型较大且游泳能力较强；其二为上层产卵鱼类，直接向水体中释放小型浮性卵，卵粒在无保护的状态下随流漂流，直至孵化出体型娇小、游泳能力孱弱的幼体。
本研究采用系统发育比较分析法（phylogenetic comparative methods），结果显示：底栖护卵鱼类的种群结构分化程度显著高于上层产卵鱼类；且底栖护卵鱼类所在的分类科，其物种丰富度亦显著高于上层产卵鱼类所在的分类科。
本研究结果为生物多样化过程中微进化与宏进化的连续性提供了有力佐证，同时凸显了与扩散相关的性状在调控进化模式与速率方面的重要意义。