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

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

Oklahoma

Congreso; Evolution 2011; 2011

Society for the Study of Evolution

Species delimitation is a major research focus in evolutionary biology because accurate species boundaries 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 alternative species delimitation hypotheses. We evaluated the performance of an ABC approach for delimiting species using simulated data and applied this method and other SDMs to lizards of the Liolaemus darwinii 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. darwinii, but the ABC method failed to detect 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 empirical data when the simulated models do not adequately describe the observed genetic variation.