Gehara Marcelo, Garda Adrian A, Werneck Fernanda P, Oliveira Eliana F, da Fonseca Emanuel M, Camurugi Felipe, Magalhães Felipe de M, Lanna Flávia M, Sites Jack W, Marques Ricardo, Silveira-Filho Ricardo, São Pedro Vinícius A, Colli Guarino R, Costa Gabriel C, Burbrink Frank T
Department of Herpetology, American Museum of Natural History, New York, NY, USA.
Departamento de Botânica e Zoologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Lagoa Nova, Natal, RN, Brazil.
Mol Ecol. 2017 Sep;26(18):4756-4771. doi: 10.1111/mec.14239. Epub 2017 Aug 24.
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. Second, we applied the hABC models to a data set of seven squamate and four 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 increase 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.
许多研究表明，第四纪气候循环收缩和/或扩大了物种和生物群落的分布范围。生物群落强烈的扩张-收缩动态意味着相关动物群在人口统计学上的协同变化。对人口统计学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多样化过程的影响。分层近似贝叶斯计算（hABC）是一种强大且灵活的方法，可对多个物种的遗传数据进行建模，并可用于估计人口统计过程的时间一致性。利用现有的单基因座数据，我们现在可以在物种数量和地理范围方面进行大规模分析。在这里，我们首先比较了四种替代hABC模型对一组单基因座数据的效能。我们发现，纳入了关于同时发生的人口统计学变化时间的先验假设的模型表现最佳。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（卡廷加）中出现的七个有鳞目物种和四个两栖类物种的数据集。根据古气候证据，该地区在更新世期间干旱加剧。如果这种干旱加剧对相关的适应干旱环境的物种多样化很重要，那么在群落水平上应该会出现同步的种群扩张。我们在晚更新世发现了强烈的同步种群扩张信号，支持了卡廷加在这一时期的扩张。这种扩张可能促进了适应高干旱和季节性的群落的形成，并导致适应潮湿森林的分类群在该地区灭绝。
