DOI: 10.5061/dryad.c61n5
title: Data from: Shaping species with ephemeral boundaries: the distribution and genetic structure of the desert tortoise (Gopherus morafkai) in the Sonoran Desert region

description: Aim: We examine the role biogeographical features played in the evolution
 of Morafka's desert tortoise (Gopherus morafkai) and test the
 hypothesis that G. morafkai maintains genetically distinct lineages
 associated with different Sonoran Desert biomes. Increased knowledge of
 the past and present distribution of the Sonoran Desert region's
 biota provides insight into the forces that drive and maintain its
 biodiversity. Location: Sonoran Desert biogeographical region; Sonora and
 Sinaloa, Mexico and Arizona, USA. Methods: We examined wild tortoises from
 Mexico (n = 155) and Arizona (n = 78), spanning their known distribution.
 We used mtDNA sequences to reconstruct matrilineal relationships and 25
 microsatellite (STR) loci for Bayesian analyses of gene flow. We performed
 clinal analyses on both mtDNA and STR loci to determine the position and
 amount of introgression where lineages co-occur. We used GIS to assess the
 association of genetic structuring with ecological features. We used these
 data in a hypothesis-driven approach to assess different models of how
 genetic diversity is maintained and distributed in G. morafkai. Results:
 Gopherus morafkai was found to comprise genetically and geographically
 distinct ‘Sonoran’ and ‘Sinaloan’ lineages. Both lineages occurred in a
 relatively narrow zone of overlap in Sinaloan thornscrub, where it
 transitions into Sonoran desertscrub. Limited introgression occurred at
 the contact zone. The best-fit model suggests that these lineages diverged
 in parapatry where the distribution of genotypes is environment-dependent
 and introgression is inhibited by exogenous selection. Main conclusions:
 The historically shifting ecotone between tropical deciduous forest and
 Sonoran desertscrub appears to be a boundary that fostered divergence
 between parapatric lineages of tortoises. The sharp genetic cline between
 the two lineages suggests that periods of isolation in temporary refugia
 due to Pleistocene climatic cycling influenced divergence. Despite
 incomplete reproductive isolation, the Sonoran and Sinaloan lineages of G.
 morafkai are on separate evolutionary trajectories.
description: Microsatellite Data
 (GenePop file format) plus sample informationMicrosatellite dataset
 used in: Edwards, T., M. Vaughn, P. C. Rosen, C. Meléndez-Torres, A. E.
 Karl, M. Culver, and R. W. Murphy. Shaping species with ephemeral
 boundaries; the distribution and genetic structure of the desert tortoise
 (Gopherus morafkai) in the Sonoran Desert. Journal of Biogeography.
 Mocrosatellite data scored as allelic values (repeat count). File contains
 sample locality information and additional data from 20 captive animals
 genotyped from El Centro Ecológico del Estado de Sonora, summarized in;
 Edwards, T. (2015) A biogeographic perspective of speciation among desert
 tortoises in the genus Gopherus. PhD Dissertation, University of Arizona,
 Tucson, Arizona USA.EdwardsEtAl_ShapingSpeciesWithEphemeralBoundaries_SampleInfo&MSATdata_JBioGeography_06Nov2015