"The Great American Biotic Interchange and the diversification of Teiidae".
Diversification, ecological opportunity, phylogenetics, niche overlap, Teiidae
Diversity patterns can vary widely across branches of a phylogeny. Evolutionary novelties and historical events such as the colonization of new environments and interaction with invaders can lead sister lineages to exhibit a significant discrepancy in species richness. One of the most relevant historical events for the composition of New World fauna was the Great American Biotic Interchange (GABI), which consisted of large-scale migratory pulses between lineages from South America and North America after the formation of the Isthmus of Panama. Despite an extensive literature describing migration and diversification patterns related to GABI, a great portion of the knowledge about this phenomenon was built on the study of mammals. In this work, I assessed the variation in diversification rates of Teiidae, a lineage of Neotropical lizards that migrated toward North America during the Miocene. Subsequently, I tested whether the diversification of these lizards is associated with geographical distribution or some phenotypic traits such as body size and body temperature. Finally, I evaluated the niche overlap between the clade that colonized Central America, North America, and the Antilles, and its sister group in South America. The results show evidence of an increase in diversification rates at two points in the group's history, one of which occurred within the clade that reached North America. Species with distribution in North America had higher diversification rates than South American species. Body size and temperature, however, did not influence the diversification rate. The results of the niche overlap analysis indicate that the clade that migrated through the Isthmus of Panama occupies a broader ecological niche, which includes almost the whole niche occupied by the sister group in South America, along with a large expansion into more arid areas. This is consistent with the hypothesis of exploiting ecological opportunities in environmental conditions for which these lizards were already preadapted.