Shifting habitats, morphology and selective pressures: developmental polyphenism in an adaptive radiation of Hawaiian spiders

Particularly intriguing examples of adaptive radiation are those in which lineages show parallel or convergent evolution, suggesting utilization of similar genetic or developmental pathways. The current study focuses on an adaptive radiation of Hawaiian “spiny-leg” spiders in which diversification is associated with repeated convergent evolution leading to similar sets of ecomorphs on each island. However, two species on the oldest islands in the archipelago exhibit variability, occurring as two different ecomorphs. More derived species on the younger islands show much less variability, any one species displaying a single ecomorph. We measured ecomorphological features within individuals over time to determine the nature of the variability. Then, using transcriptomes, we conducted lineage-based tests for selection under varying models and analyses of gene tree versus species tree incongruencies. Our results provide strong evidence that variability in color in Tetragnatha kauaiensis and ...适应性辐射（adaptive radiation）中尤为引人关注的案例，是那些类群呈现平行演化或趋同演化的类群，这暗示它们利用了相似的遗传或发育通路。本研究聚焦于夏威夷群岛“棘腿”蜘蛛的适应性辐射类群，其物种多样化与反复的趋同演化相关，最终在每个岛屿上形成了相似的生态形态（ecomorph）组合。然而，该群岛最古老岛屿上的两个物种展现出形态变异，可呈现两种不同的生态形态。而位于更年轻岛屿上的更衍生物种，其形态变异程度则显著更低，每个物种仅表现出单一的生态形态。我们通过在不同时间点测量个体的生态形态学特征，以明确该变异的本质。随后，我们借助转录组（transcriptome）数据，基于不同选择模型开展了谱系水平的选择检验，并对基因树与物种树的不一致性进行了分析。我们的研究结果为考艾岛长脚蛛（Tetragnatha kauaiensis）的体色变异提供了强有力的证据，以及……