DOI: 10.5061/dryad.jg81r80
title: Data from: Genetic signatures of small effective population sizes and demographic declines in an endangered rattlesnake, Sistrurus catenatus

description: Endangered species that exist in small isolated populations are at
 elevated risk of losing adaptive variation due to genetic drift. Analyses
 that estimate short-term effective population sizes, characterize
 historical demographic processes, and project the trajectory of genetic
 variation into the future are useful for predicting how levels of genetic
 diversity may change. Here, we use data from two independent types of
 genetic markers (single nucleotide polymorphisms [SNPs] and
 microsatellites) to evaluate genetic diversity in 17 populations spanning
 the geographic range of the endangered eastern massasauga rattlesnake
 (Sistrurus catenatus). First, we use SNP data to confirm previous reports
 that these populations exhibit high levels of genetic structure (overall
 Fst = 0.25). Second, we show that most populations have contemporary Ne
 estimates less than 50. Heterozygosity-fitness correlations in these
 populations provided no evidence for a genetic cost to living in small
 populations, though these tests may lack power. Third, model-based
 demographic analyses of individual populations indicate that all have
 experienced declines, with the onset of many of these declines occurring
 over timescales consistent with anthropogenic impacts (&lt;200 years).
 Finally, forward simulations of the expected loss of variation in
 relatively large (Ne = 50) and small (Ne = 10) populations indicate they
 will lose a substantial amount of their current standing neutral variation
 (63% and 99%, respectively) over the next 100 years. Our results argue
 that drift has a significant and increasing impact on levels of genetic
 variation in isolated populations of this snake, and efforts to assess and
 mitigate associated impacts on adaptive variation should be components of
 the management of this endangered reptile.
description: Barcode_FilesBarcode files associated with each of the 21 fastq data files used in AftrRAD run.Sovic_etal_2018_Barcode_Files.zipRAD3_fastqFastq dataset associated with RAD3 barcode fileRAD3.fastq.tar.gzRAD4_fastqFastq dataset associated with RAD4 barcode fileRAD4.fastq.tar.gzRAD5_fastqFastq dataset associated with RAD5 barcode fileRAD5.fastq.tar.gzRAD7_fastqFastq dataset associated with RAD7 barcode fileRAD7.fastq.tar.gzRAD9a_fastqFastq dataset associated with RAD9a barcode fileRAD9a.fastq.tar.gzRAD10_fastqFastq dataset associated with RAD10 barcode fileRAD10.fastq.tar.gzRAD14-1_fastq (1 of 2)Partial fastq dataset associated with RAD14 barcode file. Combine with RAD14-2 prior to analysis.RAD14-1.fastq.gzRAD14-2_fastq (2 of 2)Partial fastq dataset associated with RAD14 barcode file. Combine with RAD14-1 prior to analysis.RAD14-2.fastq.gzRAD15_fastqFastq dataset associated with RAD15 barcode fileRAD15.fastq.tar.gzRAD16_fastqFastq dataset associated with RAD16 barcode fileRAD16.fastq.tar.gzRAD18_fastqFastq dataset associated with RAD18 barcode fileRAD18.fastq.gzRAD19_fastqFastq dataset associated with RAD19 barcode fileRAD19.fastq.tar.gzRAD20_fastqFastq dataset associated with RAD20 barcode fileRAD20.fastq.tar.gzRAD21_fastqFastq dataset associated with RAD21 barcode fileRAD21.fastq.tar.gzRAD22-1_fastq (1 of 2)Partial fastq dataset associated with RAD22 barcode file. Combine with RAD22-2 prior to analysis.RAD22-1.fastq.gzRAD22-2_fastqPartial fastq dataset associated with RAD22 barcode file. Combine with RAD22-1 prior to analysis.RAD22-2.fastq.gzRAD24_fastqFastq dataset associated with RAD24 barcode fileRAD24.fastq.tar.gzRAD26_fastqFastq dataset associated with RAD26 barcode fileRAD26.fastq.tar.gzRAD28_fastqFastq dataset associated with RAD28 barcode fileRAD28.tar.gzRAD30A_fastqFastq dataset associated with RAD30A barcode fileRAD30A.fastq.gzRAD30B_fastqFastq dataset associated with RAD30B barcode fileRAD30B.fastq.gzRAD42-1_fastq (1 of 2)Partial fastq dataset associated with RAD42 barcode file. Combine with RAD42-2 prior to analysis.RAD42-1.fastq.gzRAD42-2_fastq (2 of 2)Partial fastq dataset associated with RAD42 barcode file. Combine with RAD42-1 prior to analysis.RAD42-2.fastq.gzRAD41_fastqFastq dataset associated with RAD41 barcode fileRAD41.fastq.gz