Data from: Estimating synchronous demographic changes across populations using hABC and its application for a herpetological community from northeastern Brazil

Many studies propose that Quaternary climatic cycles contracted and /or expanded the ranges of species and biomes. Strong expansion-contraction dynamics of biomes presume concerted demographic changes of associated fauna. The analysis of temporal concordance of demographic changes can be used to test the influence of Quaternary climate on diversification processes. Hierarchical approximate Bayesian computation (hABC) is a powerful and flexible approach that models genetic data from multiple species, and can be used to estimate the temporal concordance of demographic processes. Using available single-locus data we can now perform large-scale analyses, both in terms of number of species and geographic scope. Here we first compared the power of four alternative hABC models for a collection of single-locus data. We found that the model incorporating an a priori hypothesis about the timing of simultaneous demographic change had the best performance. Secondly, we applied the hABC models to a dataset of 7 squamate and 4 amphibian species occurring in the Seasonally Dry Tropical Forests (Caatinga) in Northeastern Brazil, which, according to paleoclimatic evidence, experienced an increase in aridity during the Pleistocene. If this increase was important for the diversification of associated xeric-adapted species, simultaneous population expansions should be evident at the community level. We found a strong signal of synchronous population expansion in the Late Pleistocene, supporting the expansion of the Caatinga during this time. This expansion likely enhanced the formation of communities adapted to high aridity and seasonality and caused regional extirpation of taxa adapted to wet forest.

诸多研究表明，第四纪气候旋回会收缩并/或扩张物种与生物群系的分布范围。生物群系显著的扩张-收缩动态，必然伴随相关动物类群的协同种群动态变化。对种群动态变化的时间一致性进行分析，可用于检验第四纪气候对物种分化过程的影响。分层近似贝叶斯计算（hierarchical approximate Bayesian computation, hABC）是一种高效灵活的分析方法，可对多物种的遗传数据进行建模，并用于估算种群动态过程的时间一致性。依托现有单基因座数据，当前我们已可开展兼具物种类群数量与地理覆盖范围的大规模分析。本研究首先针对一组单基因座数据，比较了四种备选hABC模型的分析效能。结果显示，纳入种群同步变化时间先验假说的模型表现最优。其次，我们将hABC模型应用于巴西东北部季节性干旱热带森林（Caatinga，卡廷加）的物种数据集，该数据集涵盖7种有鳞类动物与4种两栖动物。根据古气候证据，巴西东北部在更新世时期干旱程度加剧。若干旱加剧对相关适应干旱环境的类群的物种分化具有重要作用，则群落层面应能观测到同步的种群扩张信号。本研究在晚更新世时期检测到了显著的种群同步扩张信号，支持该时期卡廷加植被范围扩张的结论。此次扩张或促进了适应高干旱与季节波动的群落的形成，并导致适应湿润森林的类群在该区域发生局部灭绝。