title: Genetic diversity and structure in the Endangered Allen Cays Rock Iguana, Cyclura cychlura inornata.
abstract: The Endangered Allen Cays Rock Iguana (Cyclura cychlura inornata) is endemic to the Allen Cays, a tiny cluster of islands in the Bahamas. Naturally occurring populations exist on only two cays (<4 ha each). However, populations of unknown origin were recently discovered on four additional cays. To investigate patterns of genetic variation among these populations, we analyzed nuclear and mitochondrial markers for 268 individuals. Analysis of three mitochondrial gene regions (2,328 bp) and data for eight nuclear microsatellite loci indicated low genetic diversity overall. Estimates of effective population sizes based on multilocus genotypes were also extremely low. Despite low diversity, significant population structuring and variation in genetic diversity measures were detected among cays. Genetic data confirm the source population for an experimentally translocated population while raising concerns regarding other, unauthorized, translocations. Reduced heterozygosity is consistent with a documented historical population decline due to overharvest. This study provides the first range-wide genetic analysis of this subspecies. We suggest strategies to maximize genetic diversity during ongoing recovery including additional translocations to establish assurance populations and additional protective measures for the two remaining natural populations.
authors.affiliation: Department of Biological Sciences, Fordham University, New York, NY, United States; Current affiliation: College of Veterinary Medicine, Cornell University, Ithaca, NY, United States.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Aplasca
authors.affiliation: Department of Biology, Earlham College , Richmond, IN , United States.
authors.forename: John B
authors.initials: JB
authors.lastname: Iverson
authors.affiliation: Department of Biological Sciences, Mississippi State University , Mississippi, MS , United States.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Welch
authors.affiliation: Department of Biological Sciences, Mississippi State University , Mississippi, MS , United States.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Colosimo
authors.affiliation: Department of Biological Sciences, Fordham University , New York, NY , United States.
authors.forename: Evon R
authors.initials: ER
authors.lastname: Hekkala
keywords: Allen cays rock iguana; Genetic structure; Island conservation; Reintroduction