Molecular dating and diversification of the South American lizard genus Liolaemus (sub-genus Eulaemus) based on nuclear and mitochondrial DNA sequences

FONTANELLA, F.; OLAVE, M.; AVILA, L.J.; SITES, J.W., JR.; MORANDO, M.

ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2012 p. 825 - 835

0024-4082

The temperate South American lizard genus Liolaemus is the one of the most widely distributed and species-rich genera of lizards on earth. The genus is divided into two sub-genera, Liolaemus sensu  stricto (the ?Chilean group?) and Eulaemus (the ?Argentino group?), a division that is supported by recent molecular and morphological data. Due to a lack of reliable fossil data, previous studies have been forced to use either global molecular clocks, a standardized mutation rate adopted from previous studies, or the use of geological events as calibration points. However, simulations indicate that these  types of assumptions may result in less accurate estimates of divergence times when clock-like models or mutation rates are violated. We use a multi-locus data set combined with a newly described fossil to provide the first calibrated phylogeny for the crown groups of the clade Eulaemus, and derive new fossil-calibrated substitution rates (with error) of both nuclear and mtDNA gene regions for Eulaemus specifically. Divergence date estimates for each of the crown groups and appropriate rate estimates will provide the foundation for understanding rates of speciation, historical biogeography, and phylogeographic history for various clades in one of the most diverse lizard genera in the poorly studied Patagonian region.