Data from: The geography of morphological convergence in the radiations of Pacific Sebastes rockfishes

The evolution of convergent phenotypes in lineages subject to similar selective pressures is a common feature of adaptive radiation. In geographically replicated radiations, repeated convergence occurs between clades occupying distinct regions or islands. Alternatively, a clade may repeatedly reach the same adaptive peaks in broadscale sympatry, resulting in extensive convergence within a region. Rockfish (Sebastes sp.) have radiated in both the northeast and northwest Pacific, allowing tests of the extent and geographic pattern of convergence in a marine environment. We used a suite of phylogenetically informed methods to test for morphological convergence in rockfish. We examined patterns of faunal similarity using nearest neighbor distances in morphospace and the frequency of morphologically similar yet distantly related species pairs. The extent of convergence both between regions and within the northeast Pacific exceeds the expectation under a Brownian motion null model, although constraints on trait space could account for the similarity. We then used a recently developed method (SURFACE) to identify adaptive peak shifts in Sebastes evolutionary history. We found that the majority of convergent peak shifts occur within the northeast Pacific rather than between regions and that the signal of peak shifts is strongest for traits related to trophic morphology. Pacific rockfish thus demonstrate a tendency toward morphological convergence within one of the two broad geographic regions in which they have diversified.

处于相似选择压力下的各演化支系中，趋同表型的演化是适应性辐射（adaptive radiation）的典型特征之一。在地理上重复发生的辐射演化事件中，重复趋同现象会出现在占据不同区域或岛屿的演化支之间。而另一种演化模式下，单个演化支可在大范围同域分布的背景下，反复抵达相同的适应峰，进而在单一区域内引发广泛的趋同演化。平鲉属（Sebastes sp.）鱼类在东北太平洋与西北太平洋均发生了辐射演化，这为我们在海洋环境中检验趋同演化的程度与地理格局提供了绝佳的研究系统。本研究采用一系列基于系统发育框架的分析方法，对平鲉属鱼类的形态趋同现象进行检验。我们通过形态空间（morphospace）中的最近邻距离，以及形态相似但亲缘关系较远的物种对的出现频率，分析了动物群的相似性模式。研究发现，无论是不同区域之间还是东北太平洋内部的形态趋同程度，均超出了布朗运动零模型（Brownian motion null model）的预期值，尽管性状空间的约束效应或许可以解释这种相似性。随后我们使用新近开发的SURFACE方法，识别平鲉属演化历史中的适应峰位移事件。结果显示，绝大多数趋同性的适应峰位移事件均发生在东北太平洋内部，而非不同区域之间；且适应峰位移的信号在与营养形态学（trophic morphology）相关的性状中表现最为显著。综上，太平洋平鲉属鱼类展现出在其分化的两大地理区域之一内部，倾向于发生形态趋同演化的演化特征。