Adaptive morphological shifts to novel habitats in marine sculpin fishes

Sculpin fishes of the North American Pacific Coast provide an ideal opportunity to examine whether adaptive morphological character shifts have facilitated occupation of novel habitat types because of their well-described phylogeny and ecology. In this group, the basal-rooted species primarily occupy the subtidal habitat, whereas the species in the most distal clades are found in the intertidal. We tested multiple evolutionary models to determine whether changes in body size and changes in number of scales are adaptive for habitat use in sculpins. Based on a statistically robust, highly resolved molecular phylogeny of 26 species of sculpins, in combination with morphometric and habitat affinity data, our analyses show that an adaptive model based on habitat use best explains changes in body size and number of scales. The habitat model was statistically supported over models of neutral evolution, stabilizing selection across all habitats, and three clade-based models. We suggest that los...北美太平洋沿岸的杜父鱼（sculpin）是探究适应性形态性状演化是否推动物种占据新型生境的理想研究类群，这得益于该类群已被充分阐明的系统发育与生态学背景。该类群中，基部起源的物种主要栖息于潮下带生境，而演化分支最末端的物种则分布于潮间带。本研究针对杜父鱼开展多套演化模型检验，以明确体型变化与鳞片数量变化是否为适应不同生境利用的适应性特征。基于涵盖26种杜父鱼的统计稳健、高分辨率分子系统发育树，并结合形态测量数据与生境亲和性数据，本研究的分析结果显示，基于生境利用的适应性模型能够最优解释杜父鱼的体型与鳞片数量变化。相较于中性演化模型、全生境稳定选择模型以及三类基于演化分支的模型，该生境模型在统计学上得到显著支持。我们推测，los……