Four Species Linked by Three Hybrid Zones: Two Instances of Repeated Hybridization in One Species Group (Genus Liolaemus)

Hybridization is an evolutionary process that can generate diverse outcomes, such as reinforcing species boundaries, generating new species, or facilitating the introgression of locally-adapted alleles into genomic backgrounds. Liolaemus a highly clade South American lizards with ~260 and many ten are described each year. Previous studies have detected gene flow among using phylogenetic network methods and/or through comparisons nuclear mitochondrial DNA patterns, yet no study has systematically studied hybrid zones between species. Here, we compared three four in fitzingerii group Central Argentina where two L. melanops xanthoviridis , hybridize other ( shehuen ). We sampled transects were ~120 km length sequenced both genome-wide SNP data for 267 individuals. In our analyses DNA, also bi-allelic SNPs to phased (50 bp RAD loci). Population structure confirmed boundaries separating sharp, all clines <65 wide. Cline center estimates consistent alleles, but cline width significantly different producing wider estimates. The narrower shifted 4–20 southward comparison zones, indicating either sex-biased dispersal (males northward females southward), population densities unequal, moving north over time. These indicate some patterns hybridization similar across (mtDNA south), whereas variable. common geographically localized; further needed investigate whether act hard promoters speciation processes reinforcement. Nonetheless, this provides insights biotic abiotic mechanisms helping maintain within speciose system.