Quaternary range and demographic expansion of Liolaemus darwinii (Squamata: Liolaemidae) in the Monte Desert of Central Argentina using Bayesian phylogeography and ecological niche modelling

Until recently, most phylogeographic approaches have been unable to distinguish between demographic and range expansion processes, making it difficult to test for the possibility of range expansion without population growth and vice versa. In this study, we applied a Bayesian phylogeographic approach to reconstruct both demographic and range expansion in the lizard Liolaemus darwinii of the Monte Desert in Central Argentina, during the Late Quaternary. Based on analysis of 14 anonymous nuclear loci and the cytochrome b mitochondrial DNA gene, we detected signals of demographic expansion starting at ~55 ka based on Bayesian Skyline and Skyride Plots. In contrast, Bayesian relaxed models of spatial diffusion suggested that range expansion occurred only between ~95 and 55 ka, and more recently, diffusion rates were very low during demographic expansion. The possibility of population growth without substantial range expansion could account for the shared patterns of demographic expansion du...

直到最近，大多数系统发生地理学（phylogeography）方法仍无法区分种群扩张与分布区扩张过程，这使得检验无种群增长的分布区扩张可能性（或反之）变得困难。本研究采用贝叶斯系统发生地理学方法，重建了晚第四纪时期阿根廷中部蒙特沙漠中达尔文柔蜥（Liolaemus darwinii）的种群扩张与分布区扩张过程。基于14个匿名核基因座（anonymous nuclear loci）与细胞色素b线粒体DNA基因（cytochrome b mitochondrial DNA gene）的分析，通过贝叶斯天际线图（Bayesian Skyline Plot）与Skyride图（Skyride Plot），我们检测到始于约55千年的种群扩张信号。相比之下，空间扩散的贝叶斯松弛模型（Bayesian relaxed models of spatial diffusion）显示，分布区扩张仅发生在约95千年至55千年之间；而在更近的种群扩张时期，扩散速率极低。无显著分布区扩张的种群增长可能性，或许可以解释种群扩张的共同模式……