Species delimitation with ABC and other coalescent-based methods of lizards in the Liolaemus darwinii complex (Squamata, Liolaemidae)

CARMARGO, A.; MORANDO, M.; AVILA, L.J.; SITES, J. W. JR.

San Carlos de Bariloche

Congreso; XII Congreso Argentino de Herpetología; 2011

Sociedad Argentina de Herpetologia-Universidad Nacional del Comahue

Species delimitation is a major research focus in evolutionary biology because accurate speciesboundaries are a prerequisite for the study of speciation. New species delimitation methods (SDMs can accommodate non-monophyletic species and gene tree discordance as a result of incomplete lineage sorting via the coalescent model, but do not explicitly accommodate for gene flow. Approximate Bayesian Computation (ABC) can incorporate gene flow and estimate other relevant parameters of the speciation process while testing altemative species delimitation hypotheses. We evaluated the performance of an ABC approach for delimiting species using simulited data and applied this method and other SDMs to lizards of the Liolaemus dar-winii complex. The speciation model can be correctly inferred when using non-linear regression ABC despite increasing migration rates and biased parameter estimates. Maximum likelihood and Bayesian SDMs consistently supported the distinctness of southern and northern lineages within L. datwinii, but the ABC method failed to cietect separate lineages probably as a result of shallow divergence times and/or poor model fitting of the empirical data. ABC can successfully delimit species even when gene flow occurred after speciation but caution is necessary in analyzing empiricai data when the simulated models do not adequately describe the observed genetic variation.