The niches of nuthatches affect their lineage evolution differently across latitude

Ecological niche evolution can promote or hinder the differentiation of taxa and determine their distribution. Niche‐mediated evolution may differ among climatic regimes, and thus species that occur across a wide latitudinal range offer a chance to test these heterogeneous evolutionary processes. In this study, we examine (1) how many lineages have evolved across the continent‐wide range of the Eurasian nuthatch (Sitta europaea), (2) whether the lineages’ niches are significantly divergent or conserved, and (3) how their niche evolution explains their geographic distribution. Phylogenetic reconstruction and ecological niche models (ENMs) showed that the Eurasian nuthatch contained six parapatric lineages that diverged within two million years and did not share identical climatic niches. However, the niche discrepancy between these distinct lineages was relatively conserved compared with the environmental differences between their ranges and thus was unlikely to drive lineage divergence....

生态位演化既可以推动也可以阻碍类群的分化，并决定其分布格局。生态位介导的演化在不同气候格局下存在差异，因此分布于广阔纬度跨度内的物种为检验这类异质性演化过程提供了研究契机。本研究旨在探讨三个科学问题：(1) 在欧亚䴓（Sitta europaea）的整个大陆分布范围内，演化出了多少个系统发育支系？(2) 这些支系的生态位是否存在显著分化或演化保守？(3) 它们的生态位演化如何解释其地理分布格局。系统发育重建与生态位模型（ecological niche models, ENMs）结果显示，欧亚䴓包含6个邻域分布支系，这些支系在200万年内发生分化，且并未共享完全一致的气候生态位。然而，相较于这些支系分布区间的环境差异，这些不同支系间的生态位差异相对保守，因此生态位演化不太可能是驱动支系分化的原因。