Exploring the role of climatic niche changes in the evolution of the southern South American genus Baripus (Coleoptera: Carabidae): optimization of non-hereditary climatic variables and phylogenetic signal measurement.

Abstract

Baripus is a ground beetle genus endemic to southern South America, currently distributed across grassland and shrub habitats in mountain and lowland regions. The species of this genus are known to have been affected by the Andean orogeny and the climate changes that occurred during this process. In this study, we seek to understand how the orogeny of the Andes may have led to changes in the climatic niches of the species of Baripus over time. We integrated former ecological and historical biogeographic hypotheses, exploring the use of parsimony optimization of phylogenetically structured climate variables and ancestral character state reconstruction methods. We then performed regression analyses of the optimized climatic niche variables within the phylogenetic tree of Baripus. We were able to infer significant climatic niche constraints, and niche changes that provide new insights to the existing knowledge, supporting former ecological and biogeographic hypotheses for this genus. Such trends in climatic niche could be explained by the rain shadow effect caused by the Andean uplift as well as with other climate shifts associated with temperature and precipitation swings that occurred in this region from the Middle Miocene to the Pliocene.