Alice in Lizardland: exploring the spatiotemporal speciation and morphological evolutionary rates in the highly diverse microteiid lizards (Squamata: Gymnophthalmidae)

Macroevolutionary analyses can identify patterns associated with the origin and diversification of species. Here, we gathered currently available genetic and morphological information to explore the diversification dynamics in a highly diverse family of squamate lizards, Gymnophthalmidae. We downloaded the available GenBank data for four genetic markers (12S, 16S, ND4, and c-mos) and generated a dated phylogenetic hypothesis to use as an operational framework. Using our time-calibrated tree, we conducted a Bayesian analysis of macroevolutionary mixtures (BAMM) to explore macroevolutionary patterns for both speciation and phenotypic evolution. For the latter, we included two morphological traits: body size and leg development. We recovered six major clades commonly referred to as subfamilies, whose common ancestor was recovered between 78.15 and 81.68 Myr. Additionally, we found that the major accumulation of extant lineages occurred during the Miocene. Overall, all the evolutionary rates tended to be low, with particular clades exhibiting higher rates and different but not congruent points of acceleration along the tree. These findings indicate that speciation and phenotypic evolution in this lizard group are heterogenic and decoupled, but several pulses of diversification have occurred. Geographically, we found older lineages to be concentrated in the Amazon and the Guiana Shield, whereas higher speciation rates are found in the tropical Andes and its adjacent lowlands.