Pedro de Oliveira Calixto
Doutorado | 3° ano
Same processes but different pathways: The role of climate in the evolutionary history of Viperidae
Same processes but different pathways: The role of climate in the evolutionary history of Viperidae
Climate is selective pressure for ectotherms, influencing the behavioral and physiological responses of these organisms. Also, by consequence, scaling to the evolutionary history of these groups. Thereby, evaluating the evolutionary dynamics of the climatic niche space is a key step to understand the current patterns of geographic distribution and diversity. Besides, it is unclear which contribution of the temporal variation of abiotic variables, over geological scales, has on diversification dynamics, making it a crucial piece in understanding the structuring of diversity patterns. Therefore, to tackle this question, we use climatic data associated with the geographical distribution of 256 species of Viperidae together with their phylogenetic relationships to determine the tempo and mode of the evolution of the climatic niche occupation. Also, we use temperature-dependent and time-dependent models to determine which models best describes the diversification rates of Viperidae and their subfamilies. Our results demonstrated an important role of climate in the evolutionary history of Viperidae, which emerges from different evolutionary responses of their subfamilies. We observed a different occupancy and diversification of the climatic niche space for Viperinae and Crotalinae, even though the evolution process was the same for both groups. The mode of evolution for Viperidae and their subfamilies was best described by an Ornstein-Uhlenbeck model, which suggests niche conservatism. The best model to explain the diversification rates for Viperidae was the temperature-dependent model, affecting mainly through the extinction rates in Crotalinae. So, climate change in the geological scales played an important role in patterns of diversity and structuring of the occupancy and diversification of climatic niche in Viperidae.
poster_D_3_Pedro_Calixto.pdf