Data from: Testing the geographical dimensions of genetic diversity following range expansion in a North American snake

Spatial and demographic expansion can alter patterns of genetic variation and have predictable spatial and temporal consequences. Two-dimensional range expansion should result in genetic variation that is correlated with the geographical axis of expansion. Notably, populations across the range of a geographically widespread species may asynchronously experience expansion and contraction events. We tested for the genetic consequences of range expansion in the flat-headed snake, Tantilla gracilis, which inhabits the North American Great Plains, which has few barriers to terrestrial dispersal. We sequenced mitochondrial (mtDNA) and nuclear DNA from across the range of T. gracilis, inferred phylogenies, and constructed haplotype networks. We observed multiple geographically circumscribed mtDNA clades that varied greatly in their spatial extent, but little range-wide variation in nuclear DNA. Mitochondrial sequence variation was negatively associated with latitude across their geographic range, the expected pattern of northward expansion. Finally, the three largest mtDNA clades exhibited varying demographic patterns, with only one consistent with recent expansion. Despite substantial mtDNA cladogenesis, the predicted signature of northern range expansion was still detectable in T. gracilis. Our results bolster the notion that Post-Pleistocene range expansion was a dominant force shaping the genetic diversity of vertebrates in central North America.Tantilla_ND4CytB_phylogeographyAlighnment file containing NADH dehydrogenase subunit 4 (ND4) and flanking tRNAs (685 bp) concatenated with cytochrome b (cyt-b, 666 bp) for Conopsis biserialis, Coluber constrictor, Tantilla nigriceps (2 samples), T. wilcoxi (2 samples), T. relicta, T. coronata (2 samples), T. planiceps, and T. gracilis (77 samples). Each sequence id has a unique numerical ID for each sample. See associated manuscript (Table 1) for additional information for each sample.Tantilla_BDNF_gracilis_prunedAlignment file containing sequence (421 bp) of brain derived neurotropic factor (BDNF) for Tantilla wilcoxi (2 samples), T. coronata (3 samples), and T. gracilis (19 samples). Each sequence id has the unique numerical id for each sample. See associated manuscript (Table 1) for additional information for each sample.Tantilla_rag1_gracilis_prunedAlignment file containing sequence (478 bp) of recombination activating gene 1 (RAG-1) for Tantilla wilcoxi, T. coronata, T. relicta, T. nigriceps (2 samples), and T. gracilis (20 samples). Each sequence id has the unique numerical id for each sample. See associated manuscript (Table 1) for additional information for each sample.Tantilla_SNCAIP_gracilis_prunedAlignment file containing sequence (261 bp) of synuclein alpha interacting protein (SNCAIP) for Tantilla wilcoxi, T. coronata (3 samples), T. nigriceps, and T. gracilis (21 samples). Each sequence id has the unique numerical id for each sample. See associated manuscript (Table 1) for additional information for each sample