Exploratory analysis of the genetic diversity for two Phyllodactylus species in contrasting environments

Historically, the genetic diversity of insular species and populations has generally been considered to be lower with respect to their continental counterparts. In this study, I compare for first time the genetic diversity of two gecko species, Phyllodactylus angelensis and P. magnus, that inhabit contrasting environments in Mexico (island and mainland, respectively). Utilizing genomic data for both species generated through genotyping by sequencing (GBS), I performed paired comparisons of various genetic diversity indices analyzing thousands of single nucleotide polymorphism (SNP) variants. The majority of genetic diversity indices demonstrated very similar values between both species, while the observed heterozygosity and genetic diversity within populations was higher for the insular species. The results do not support the generalized assumption of lower genetic diversity in island species. Key aspects such as the effective population size of founders, gene flow, and shared life histories may be involved in explaining the observed pattern.