Meeting Abstract

P3.4  Wednesday, Jan. 6  Genetic diversity within and among three different populations of the gopher tortoise (Gopherus polyphemus) CARRUTH, W. C.*; HUTCHISON, N. L.; HARRISON, J. S.; ROSTAL, D. C.; Georgia Southern University; University of Louisiana at Lafayette; Georgia Southern University; Georgia Southern University wcarrut1@georgiasouthern.edu

The gopher tortoise, Gopherus polyphemus, is considered a keystone species in sand hill, longleaf pine, and scrub ecosystems of the southeastern United States. The current distribution of G. polyphemus is highly fragmented due to habitat loss and degradation resulting in isolated populations that vary significantly in size. Populations that experience a decrease in size can experience a decrease in genetic diversity. Those that remain small and isolated for long periods of time are expected to lose genetic variation through random genetic drift and increased levels of inbreeding. This loss of genetic variation can result in lower average fitness and decreased adaptive potential. This study focuses on three isolated populations of G. polyphemus that differ in their estimated consensus population size: George L. Smith State Park, Georgia (GLS) at 300-500 individuals; Fort Stewart Army Reservation, Georgia (FSAR) at 3000-5000 individuals; and Kennedy Space Center, Merritt Island, Florida (KSC) at >15,000 individuals. The main objective is to characterize the genetic variation within and among GLS, FSAR, and KSC populations of G. polyphemus using 8 microsatellite loci. Two primary questions are addressed: 1) What is the degree of population genetic subdivision among the three populations? and 2) Is the level of genetic variation (allelic diversity, expected heterozygosity, etc.) lower in smaller populations? Possible effects of lowered genetic diversity in tortoises will be discussed.