Quaternary range and demographic expansion of Liolaemus darwinii (Squamata: Liolaemidae) in the Monte Desert of Central Argentina using Bayesian phylogeography and ecological niche modelling

CAMARGO, A.; WERNECK, F.; MORANDO, M.; SITES, J.W., JR.; AVILA, L.J.

MOLECULAR ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2013 vol. 22 p. 4038 - 4054

0962-1083

Until recently, most phylogeographic approaches have been unable to distinguishbetween demographic and range expansion processes, making it difficult to test for thepossibility of range expansion without population growth and vice versa. In this study,we applied a Bayesian phylogeographic approach to reconstruct both demographic andrange expansion in the lizard Liolaemus darwinii of the Monte Desert in CentralArgentina, during the Late Quaternary. Based on analysis of 14 anonymous nuclearloci and the cytochrome b mitochondrial DNA gene, we detected signals of demographicexpansion starting at ~55 ka based on Bayesian Skyline and Skyride Plots. Incontrast, Bayesian relaxed models of spatial diffusion suggested that range expansionoccurred only between ~95 and 55 ka, and more recently, diffusion rates were very lowduring demographic expansion. The possibility of population growth without substantialrange expansion could account for the shared patterns of demographic expansionduring the Last Glacial Maxima (OIS 2 and 4) in fish, small mammals and other lizardsof the Monte Desert. We found substantial variation in diffusion rates over time, andvery high rates during the range expansion phase, consistent with a rapidly advancingexpansion front towards the southeast shown by palaeo-distribution models. Furthermore,the estimated diffusion rates are congruent with observed dispersal rates oflizards in field conditions and therefore provide additional confidence to the temporalscale of inferred phylogeographic patterns. Our study highlights how the integrationof phylogeography with palaeo-distribution models can shed light on both demographicand range expansion processes and their potential causes.