Population genomics of big mice from the Faroe islands: Hybridization, colonization, and a new challenge to identifying genomic targets of selection

Populations that colonize islands provide unique insights into demography, adaptation, and the spread of invasive species. House mice on the Faroe Islands evolved exceptionally large bodies after colonization, generating interest from biologists going back to Darwin. To reconstruct the evolutionary history of these mice, we sequenced genomes of population samples from three Faroe Islands (Nolsoy, Sandoy, Mykines) and Norway as a mainland comparison. Mice from the Faroe Islands are inferred to be hybrids between the subspecies Mus musculus domesticus and M. m. musculus, with ancestry alternating along the genome. The mice are predominantly M. m. domesticus in origin, reflecting repeated backcrossing to this subspecies following initial hybridization. Analyses based on the site frequency spectrum of single nucleotide polymorphisms and the ancestral recombination graph indicate that mice spread to the Faroe Islands on a timescale consistent with dispersal by Norwegian Vikings, with coloniz..., , , # Population genomics of big mice from the Faroe islands: Hybridization, colonization, and a new challenge to identifying genomic targets of selection

Dataset DOI: [10.5061/dryad.5qfttdzh4](10.5061/dryad.5qfttdzh4)

## Description of the data and file structure

There are four SNP vcf files, one for each of the four following population groups: 12 unrelated wild mice from Faroe island Sandoy; 8 unrelated wild mice from Faroe island Nólsoy; 7 unrelated wild mice with *domesticus (Mus musculus domesticus)*-major ancestry (More *domesticus *ancestry than *musculus* or heterogeneous ancestry) from Norway; 6 unrelated wild mice with *musculus (Mus musculus musculus)*-major ancestry (More *musculus* ancestry than *domesticus* or heterogeneous ancestry) from Norway.

All Norway samples we sequenced are hybrids between *domesticus* and *musculus*. Tissue and DNA samples were provided by our collaborators. Illumina NovaSeq 150bp pair-end sequencing was completed by UW-Madison Genome Sequencing ...,