Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain.
Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA.
Syst Biol. 2022 Feb 10;71(2):261-272. doi: 10.1093/sysbio/syab025.
The geographic distribution of biodiversity is central to understanding evolutionary biology. Paleogeographic and paleoclimatic histories often help to explain how biogeographic patterns unfold through time. However, such patterns are also influenced by a variety of other factors, such as lineage diversification, that may affect the probability of certain types of biogeographic events. The complex and well-known geologic and climatic history of Afro-Arabia, together with the extensive research on reptile systematics in the region, makes Afro-Arabian squamate communities an ideal system to investigate biogeographic patterns and their drivers. Here, we reconstruct the phylogenetic relationships and the ancestral geographic distributions of several Afro-Arabian reptile clades (totaling 430 species) to estimate the number of dispersal, vicariance and range contraction events. We then compare the observed biogeographic history to a distribution of simulated biogeographic events based on the empirical phylogeny and the best-fit model. This allows us to identify periods in the past where the observed biogeographic history was likely shaped by forces beyond the ones included in the model. We find an increase in vicariance following the Oligocene, most likely caused by the fragmentation of the Afro-Arabian plate. In contrast, we did not find differences between observed and expected dispersal and range contraction levels. This is consistent with diversification enhanced by environmental processes and with the establishment of a dispersal corridor connecting Africa, Arabia and Eurasia since the middle Miocene. Finally, here we show that our novel approach is useful to pinpoint events in the evolutionary history of lineages that might reflect external forces not predicted by the underlying biogeographic model. [Dispersal; diversification; model adequacy; paleogeography; reptiles; simulations; vicariance.].
生物多样性的地理分布是理解进化生物学的核心。古地理和古气候历史通常有助于解释生物地理格局如何随时间展开。然而，这些模式也受到其他各种因素的影响，例如谱系多样化，这可能会影响某些类型的生物地理事件的发生概率。阿非罗-阿拉伯地区复杂而著名的地质和气候历史，以及该地区对爬行动物系统发育的广泛研究，使阿非罗-阿拉伯蜥蜴群落成为调查生物地理格局及其驱动因素的理想系统。在这里，我们重建了几个阿非罗-阿拉伯爬行动物类群（总计 430 种）的系统发育关系和祖先地理分布，以估计扩散、隔离和范围收缩事件的数量。然后，我们将观察到的生物地理历史与基于经验系统发育和最佳拟合模型的模拟生物地理事件的分布进行比较。这使我们能够识别过去观察到的生物地理历史可能受到模型中未包含的力量塑造的时期。我们发现，自渐新世以来，隔离事件增加，这很可能是由于阿非罗-阿拉伯板块的分裂造成的。相比之下，我们没有发现观察到的扩散和范围收缩水平与预期之间的差异。这与环境过程增强的多样化以及从中新世中期以来连接非洲、阿拉伯和欧亚大陆的扩散走廊的建立是一致的。最后，我们在这里表明，我们的新方法有助于确定谱系进化历史中的事件，这些事件可能反映了基础生物地理模型未预测到的外部力量。[扩散；多样化；模型充分性；古地理；爬行动物；模拟；隔离。]
