Data from: Scale-dependent adaptive evolution and morphological convergence to climatic niche in Californian eriogonoids (Polygonaceae)

Aim: Macroevolutionary patterns and processes change substantially depending on levels of taxonomic and ecological organization, and the resolution of environmental and spatial variability. In comparative methods, the resolution of environmental and spatial variability often defines the number of selective regimes used to test whether phenotypic characteristics are adaptively correlated with the environment. Here, we examine how investigator choice of the number of selective regimes, determined by varying the resolution of among-species variability in the species climatic niche (hereafter called ‘ecological scale’), influences trait morphological diversification among Eriogonoideae species. We assess whether adaptive or neutral processes drive the evolution of several morphological traits in these species. Location: South-western North America. Methods: We applied a phylogenetic framework of three evolutionary models to four morphological traits and the climatic niches of Eriogonoideae (in the buckwheat family, Polygonaceae). We tested whether morphological traits evolve in relation to climate by adaptive or neutral process, and whether the resulting patterns of morphological variability are conserved or convergent across the clade. We inspected adaptive models of evolution under different levels of resolution of among-species variability of the climatic niche. Results: We show that morphological traits and climate niches of Eriogonoideae species are not phylogenetically conserved. Further, adaptive evolution of phenotypic traits is specific to climatic niche occupancy across this clade. Finally, the likely evolutionary process and the level of detectable niche conservatism change depending on the resolution of environmental variability of the climatic niche. Main conclusions: Our study demonstrates the need to consider both the resolution of environmental variability and alternative evolutionary models to understand the morphological diversification that accompanies divergent adaptive evolution of lineages to climatic conditions.研究目的：宏观进化模式与过程（macroevolutionary patterns and processes）会随分类学与生态学组织层次、环境及空间变异的分辨率发生显著改变。在比较分析方法（comparative methods）中，环境与空间变异的分辨率通常决定了用于检验表型特征是否与环境存在适应性关联的选择格局（selective regimes）的数量。本研究探讨：通过改变物种间气候生态位（climatic niche）的变异分辨率（后文简称‘生态尺度（ecological scale）’）来调整选择格局的数量，这一研究者的选择会如何影响蓼亚科（Eriogonoideae）物种的形态性状多样化；同时评估这些物种的若干形态性状的演化究竟由适应性过程还是中性过程驱动。 研究区域：北美洲西南部。 研究方法：本研究针对蓼科（Polygonaceae）蓼亚科（Eriogonoideae）的4个形态性状与物种气候生态位，采用基于3种进化模型的系统发育分析框架（phylogenetic framework）。我们检验了形态性状的演化是否与气候相关且由适应性或中性过程驱动，同时检验该支系（clade）中形态变异的演化模式究竟为系统发育保守性（phylogenetic conserved）还是趋同演化。此外，我们在不同分辨率的物种间气候生态位变异水平下，对适应性进化模型开展了分析。 研究结果：本研究发现，蓼亚科物种的形态性状与气候生态位均不具有系统发育保守性。进一步而言，该支系表型性状的适应性演化仅与物种的气候生态位占据情况相关。最后，可推断的进化过程以及可检测到的生态位保守性水平，会随气候生态位的环境变异分辨率发生改变。 主要结论：本研究表明，若要厘清伴随谱系对气候环境产生适应性分化演化的形态多样化过程，必须同时考虑环境变异的分辨率与不同进化模型的选择。