Clinging on the brink: Whole genomes reveal human-induced population declines and severe inbreeding in the Critically Endangered Emirati Leaf-toed Gecko (Asaccus caudivolvulus).

Human-mediated habitat destruction has had a profound impact on increased species extinction rates and population declines worldwide. The coastal development in the United Arab Emirates (UAE) over the last two decades, serves as an example of how habitat transformation can alter the landscape of a country in just a few years. Here, we study the genomic implications of habitat transformation in the Critically Endangered Emirati Leaf-toed Gecko (Asaccus caudivolvulus), the only endemic vertebrate of the UAE. We generate a high-quality reference genome for this gecko, representing the first reference genome for the family Phyllodactylidae, and produce whole-genome resequencing data for 23 specimens from 10 different species of leaf-toed geckos. Our results show that A. caudivolvulus has consistently lower genetic diversity than any other Arabian species of Asaccus, suggesting a history of ancient population declines. However, high levels of recent inbreeding are recorded among populations in heavily developed areas, with a more than 50% increase in long runs of homozygosity within a 9-year period. Moreover, results suggest that this species does not effectively purge deleterious mutations, hence making it more vulnerable to future stochastic threats. Overall, results show that A. caudivolvulus is in urgent need of protection, and habitat preservation must be warranted to ensure the species' survival.