Data from: Genomic diversity, population structure, and migration following rapid range expansion in the balsam poplar, Populus balsamifera
Keller, Stephen R. et al. (2010), Data from: Genomic diversity, population structure, and migration following rapid range expansion in the balsam poplar, Populus balsamifera, Dryad, Dataset, https://doi.org/10.5061/dryad.1164
Rapid range expansions can cause pervasive changes in the genetic diversity and structure of populations. The post-glacial history of the Balsam Poplar, Populus balsamifera, involved the colonization of most of northern North America, an area largely covered by continental ice sheets during the last glacial maximum. To characterize how this expansion shaped genomic diversity within and among populations, we developed 412 SNP markers that we assayed for a range-wide sample of 474 individuals sampled from 34 populations. We complemented the SNP dataset with DNA sequence data from 11 nuclear loci from 94 individuals, and used coalescent analyses to estimate historical population size, demographic growth, and patterns of migration. Bayesian clustering identified three geographically separated demes found in the Northern, Central, and Eastern portions of the species range. These demes varied significantly in nucleotide diversity, the abundance of private polymorphisms, and population substructure. Most measures supported the Central deme as descended from the primary refuge of diversity. Both SNPs and sequence data suggested recent population growth, and coalescent analyses of historical migration suggested a massive expansion from the Center to the North and East. Collectively, these data demonstrate the strong influence that range expansions exert on genomic diversity, both within local populations and across the range. Our results suggest that an in-depth knowledge of nucleotide diversity following expansion requires sampling within multiple populations, and highlight the utility of combining insights from different data types in population genomic studies.