Efeitos diretos da temperatura sobre as taxas de especiação não explicam o gradiente latitudinal de diversidade de pequenos mamíferos sul-americanos

Abstract

One of the central focus in ecological studies is to understand how species are distributed throughout space and the factors that govern this variation. The increase of diversity from the poles to the tropics (Latitudinal Diversity Gradient) is one of the most studied geographic patterns, although the underlying mechanisms still remain elusive. Dozens of hypotheses have been proposed to explain this latitudinal variation in the number of species. The Metabolic Theory of Ecology suggests that the effects of temperature on metabolic processes may explain the patterns observed in nature by increasing speciation rates in warmer environments. In addition, stochastic processes of speciation, ecological drift, and dispersal, as proposed by the Neutral Theory of Biodiversity, may also affect species diversity. However, there are few studies that mechanistically evaluate the relationship between different ecological and evolutionary processes along latitudinal gradients. In this study, I will evaluate the capacity of metabolic and neutral processes to explain the richness patterns of didelphid marsupials and hystricomorph and myomorph rodents along the South American continent. At the end of this study, we intend to determine the importance of local stochastic processes and the effect of temperature on speciation rates in the species richness of these groups.