Collevatti Rosane G, Lima-Ribeiro Matheus S, Terribile Levi Carina, Guedes Ludymila B S, Rosa Fernanda F, Telles Mariana P C
Laboratório de Genética & Biodiversidade, Instituto de Ciências Biológicas (ICB), Universidade Federal de Goiás (UFG), Cx.P. 131, Goiânia, GO, 74001-970, Brazil.
Laboratório de Macroecologia, Universidade Federal de Goiás (UFG), Campus Jataí, Cx.P. 03, Jataí, GO, 75801-615, Brazil.
BMC Evol Biol. 2014 Oct 11;14:213. doi: 10.1186/s12862-014-0213-0.
Glaciations were recurrent throughout the Quaternary and potentially shaped species genetic structure worldwide by affecting population dynamics. Here, we implemented a multi-model inference approach to recover the distribution dynamics and demographic history of a Neotropical savanna tree, Tabebuia aurea (Bignoniaceae). Exploring different algorithms and paleoclimatic simulations, we used ecological niche modelling to generate alternative hypotheses of potential demographic changes through the last glacial cycle and estimated genetic parameters using coalescent modelling.
Comparing predictions from demographic hypotheses with genetic parameters of modern populations, our findings revealed a likely scenario of population decline, with spatial displacement towards Northeast Brazil from the last glacial maximum to the mid-Holocene. Subsequently, populations expanded in response to the return of the climatically suitable conditions in Central-West Brazil. Nevertheless, a wide historical refugium across Central Brazil likely maintained large populations connected throughout time. The expected genetic signatures from such predicted distribution dynamics are also corroborated by spatial genetic structure observed in modern populations.
By exploring uncertainties inherent in multiple working hypotheses, we have shown that multi-model inference is a fruitful and efficient approach to recover the nature, timing and geographical context of the Tabebuia aurea population dynamic in response to the Quaternary climate changes.
在整个第四纪，冰川作用反复发生，并可能通过影响种群动态塑造全球物种的遗传结构。在此，我们采用了一种多模型推断方法来恢复新热带稀树草原树木金黄风铃木（紫葳科）的分布动态和种群历史。通过探索不同算法和古气候模拟，我们利用生态位建模生成了关于末次冰期旋回期间潜在种群变化的替代假设，并使用溯祖模型估计了遗传参数。
将种群假设的预测结果与现代种群的遗传参数进行比较，我们的研究结果揭示了一种可能的种群下降情况，即从末次盛冰期到全新世中期，种群向巴西东北部发生空间位移。随后，随着巴西中西部气候适宜条件的恢复，种群数量有所增加。尽管如此，巴西中部广阔的历史避难所可能一直维持着大量种群的长期连通。现代种群中观察到的空间遗传结构也证实了这种预测的分布动态所预期的遗传特征。
通过探索多个有效假设中固有的不确定性，我们表明多模型推断是一种富有成效且高效的方法，可用于恢复金黄风铃木种群动态在应对第四纪气候变化时的性质、时间和地理背景。
