Complex patterns of diversification in the gray zone of speciation: Model-based approaches applied to Patagonian liolaemid lizards (Squamata: Liolaemus kingii clade)

In this study, we detangled the evolutionary history of the Patagonian
lizard clade Liolaemus kingii, coupling dense geographic sampling and
novel computational analytical approaches. We analyzed nuclear and
mitochondrial data (restriction DNA sequencing and cytochrome b) to
hypothesize and evaluate species limits, phylogenetic relationships, and
demographic histories. We also conducted posterior predictive simulations
to assess the fit of the genomic data to the multispecies coalescent
model. Our results show several instances of mito-nuclear discordance and
consistent support for a reticulated history, supporting the view that the
complex evolutionary history of the kingii clade is characterized by
extensive gene flow and rapid diversification events. We discuss our
findings in the contexts of the “gray zone” of speciation, phylogeographic
patterns in the Patagonian region, and taxonomic outcomes.