Data from: Speciation, population structure, and demographic history of the Mojave Fringe-toed Lizard (Uma scoparia), a species of conservation concern

The North America deserts were impacted by both Neogene plate tectonics and Quaternary climatic fluctuations, yet it remains unclear how these events influenced speciation in this region. We tested published hypotheses regarding the timing and mode of speciation, population structure, and demographic history of the Mojave Fringe-toed Lizard (Uma scoparia), a sand dune specialist endemic to the Mojave Desert of California and Arizona. We sampled 109 individual lizards representing 22 insular dune localities, obtained DNA sequences for 14 nuclear loci, and found that U. scoparia has low genetic diversity relative to the U. notata species complex, comparable to that of chimpanzees and southern elephant seals. Analyses of genotypes using Bayesian clustering algorithms did not identify discrete populations within U. scoparia. Using Isolation-with-Migration (IM) models and a novel coalescent-based hypothesis testing approach, we estimated that U. scoparia diverged from U. notata in the Pleistocene epoch. The Likelihood Ratio Test and the Akaike Information Criterion consistently rejected nested speciation models that included parameters for migration and population growth of U. scoparia. We reject the Neogene vicariance hypothesis for the speciation of U. scoparia, and define this species as a single evolutionarily significant unit for conservation purposes.

北美沙漠同时受到新近纪（Neogene）板块构造与第四纪（Quaternary）气候波动的双重影响，但目前仍不清楚这些地质气候事件如何影响该区域的物种形成过程。我们针对莫哈韦侧趾蜥（*Uma scoparia*）的物种形成时间与模式、种群结构以及种群历史展开了已发表假说的检验，该物种是栖息于加利福尼亚州与亚利桑那州莫哈韦沙漠的沙丘专性特有物种。我们采集了代表22个孤立沙丘生境种群的109只个体样本，对14个核基因座开展了DNA测序，结果显示相较于诺塔侧趾蜥物种复合体（*U. notata* species complex），莫哈韦侧趾蜥的遗传多样性水平较低，其程度与黑猩猩及南象海豹相当。基于贝叶斯聚类算法的基因型分析并未在莫哈韦侧趾蜥种群中检测到明显的分化种群。我们借助隔离与迁移（Isolation-with-Migration, IM）模型以及一种全新的溯祖假说检验方法，估算出莫哈韦侧趾蜥与诺塔侧趾蜥于更新世（Pleistocene epoch）发生分化。似然比检验（Likelihood Ratio Test）与赤池信息准则（Akaike Information Criterion）均一致拒绝了包含莫哈韦侧趾蜥迁移与种群增长参数的嵌套式物种形成模型。我们否定了莫哈韦侧趾蜥物种形成的新近纪隔离分化假说，并将该物种界定为一个可用于保护工作的单一进化显著单元（evolutionarily significant unit）。