O papel da evolução de nichos na diversificação de lagartos do gênero Kentropyx (Squamata: Teiidae)

Abstract

Evolutionary ecology and molecular biogeography studies have the important potential to assist in the understanding of patterns and processes of diversification, especially in megadiverse regions, as the Neotropics. Here, we present an extensive phylogenetic and biogeographic analysis integrated with comparative methods to investigate the niche evolution of a lizard genus (Kentropyx) widely distributed in South America, occupying forest and open vegetation formations. We estimated gene trees and a species tree based on five independent loci and recovered three clades that coincide with species groups previously recognized. The biogeographical scenario selected indicates a joint role for vicariance from an open and forest formations ancestral and a more recent funder speciation event to the Guiana Shield (striata group). Niche models and climatic tolerance profiles, within a comparative phylogenetic context, indicated niche conservatism at the groups distributed in the Amazon Basin (calcarata) and Guyana Shields (striata). On the other hand, we recovered niche divergence on the clade from the Brazilian Shield savannas (paulensis group), confirmed with niche overlap and equivalence analyzes. Niche overlap and conservatism for the calcarata group species agree with hybridization signatures found on our phylogenetic analysis, especially at the distribution limits. Our study suggests that biogeographic events and evolution of ecological niche characteristics as an adaptation to new environmental niches shaped the speciation patterns in this group of Neotropical lizards.