Identifying hybrid zones and species limits with genome-wide DNA in a promiscuous group of Liolaemus lizards

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

Hanzhou

Congreso; 8th World Congress of Herpetology; 2016

Hybridization is common in nature with approximately 10% and 25% of animal and plant species known to hybridize, respectively. With such high rates of hybridization, an obvious question is how hybridizing species are able to maintain independent evolutionary trajectories. The Liolaemus fitzingerii species group contains nine species with putative hybrid zones between three species-pairs. We first used a sequence capture dataset of 560 loci and 28 individuals to infer the species tree and identify hybrids. We then analyzed one of these hybrid zones with double digest restriction site-associated DNA (ddRAD) sequences for 170 individuals. Clustering algorithms, including discriminant analysis of principal components and Bayesian assignment methods, identified two populations in this hybrid zone. Our analyses also revealed high levels of gene flow in the central portion of this hybrid zone. We then performed geographic and genomic cline analyses to identify loci that are under strong selection and therefore are putatively involved in maintaining species boundaries. We identified four ?outlier? loci under strong selection, and we are currently doing further analyses to determine the putative function of these loci under selection. We found ample evidence that species in this group are able to remain evolutionarily distinct in spite of high levels of gene flow and morphological variation