Testing the role of climate in speciation: new methods and applications to squamate reptiles (lizards and snakes)

Climate may play important roles in speciation, such as causing the range fragmentation that underlies allopatric speciation (through niche conservatism) or driving divergence of parapatric populations along climatic gradients (through niche divergence). Here, we developed new methods to test the frequency of climate niche conservatism and divergence in speciation, and applied it to species pairs of squamate reptiles (lizards and snakes). We used a large-scale phylogeny to identify 242 sister-species pairs for analysis. From these, we selected all terrestrial allopatric pairs with sufficient occurrence records (n=49 pairs) and inferred whether each originated via climatic niche conservatism or climatic niche divergence. Among the 242 pairs, allopatric pairs were most common (41.3%), rather than parapatric (19.4%), partially sympatric (17.7%), or fully sympatric species pairs (21.5%). Among the 49 selected allopatric pairs, most appeared to have originated via climatic niche divergence (...

气候在物种形成中可能发挥重要作用，例如通过生态位保守性（niche conservatism）导致异域物种形成（allopatric speciation）的基础——分布区碎片化，或通过生态位分化（niche divergence）驱动邻域种群（parapatric populations）沿气候梯度（climatic gradients）分化。在此，我们开发了新方法以检验物种形成过程中气候生态位保守性与分化的发生频率，并将其应用于有鳞爬行动物（蜥蜴和蛇）的种对研究。我们利用大规模系统发育树（phylogeny）识别出242个姐妹种对（sister-species pairs）进行分析。从中，我们筛选出所有具有充足分布记录的陆生异域种对（n=49对），并推断每一对是否起源于气候生态位保守性或气候生态位分化。在242个种对中，异域种对最为常见（41.3%），其次是邻域种对（19.4%）、部分同域种对（17.7%）和完全同域种对（21.5%）。在筛选出的49个异域种对中，大多数似乎起源于气候生态位分化(...)