Daniela Lazo-Cancino

University of Concepción · Departamento de Zoología

This project constitutes the first exhaustive attempt to evaluate and contrast the main proposals regarding the Andean uplift effect on the diversification of South American biota. Thereby, it will possible make a coupling of the Andean orogeny with the dynamics of diversification that give rise to the current small mammal richness of this continent.

The question of what determines species diversity is a fundamental question in ecology and evolutionary biology, and considered one of the top reseach challenges in all of science. Speciation, extinction, and character evolution are historical processes involved in generating species diversity, therefore examining how the rates of these processes change can help to identify the specific macroevolutionary processes that generate diversity over time and across groups, like the distinctive presence of biodiversity hotspots (BH) of South America’s biota. Many scientific efforts have been focused within BHs, but despite that the patterns of species diversity are the result of historical process such as speciation and extinction, relevant aspects such as the origin and evolutionary history of species from BH have been less studied. Even more, the interaction between the complex geomorpholical and climate history of South America and the great diversification of many lineages are still poorly understood, despite the existence of many competing hypotheses. Therefore, the study of historical evolutionary processes that have led to the current patterns of diversity distribution, should give strong foundations for the search of common causes for the origin of South America’s biota. The use of phylogenetic based models to construct evolutionary history from living species offers a solution for evaluating hypotheses regarding the underlying causes of diversity patterns evaluating extrinsic and intrinsic drivers of species diversity. Recent years have been witness of a significant shift from descriptive to probabilistic approaches in attempt to explain long-standing questions in evolutionary biology across various temporal and spatial scales, and the origin and patterns of biodiversity at macroevolutionary level. The Bayesian revolution and likelihood-based statistical inference have been credited for much of this change. In addition, the use of evolutionary Bayesian inferences will allow researchers to quantify the uncertainty of specific evolutionary hypotheses accounting for observed biodiversity patterns and their intrinsic drivers. Also, this approach allows the forecasting of the effects of environmental factors or extrinsic drivers by studying its potential impact on diversification rates. The impetus behind this proposal is the use of probabilistic modeling approaches to study the underlying evolutionary processes and evaluate the causes that explain patterns of biodiversity among terrestrial vertebrates from South America BHs we observe today. In order to estimate the effect of evolutionary history on the observed biodiversity patterns we will use several data bases currently available for environmental and ecological factors, the genetic and phylogeny of different vertebrates as study models.