Evidence of adaptation from ancestral variation in young populations of beach mice.

摘要: To understand how organisms adapt to novel habitats, which involves both demographic and selective events, we require knowledge of the evolutionary history populations also selected alleles. There are still few cases in precise mutations (and hence, defined alleles) that contribute adaptive change have been identified nature; one exception is genetic basis camouflaging pigmentation oldfield mice (Peromyscus polionotus) colonized sandy dunes Florida's Gulf Coast. quantify genomic impact colonization as well signature selection, resequenced 5000 1.5-kb noncoding loci a 160-kb region surrounding melanocortin-1 receptor (Mc1r), gene contributes differences, beach mainland populations. Using genome-wide phylogenetic approach, recovered single monophyletic group comprised mice, consistent with event We found evidence severe founder event, estimated occurred less than 3000 years ago. In this context, show all subspecies share derived light Mc1r allele, was likely from standing variation originated mainland. Surprisingly, were unable identify clear selection region, despite independent locus coloration. Nonetheless, these data allow us reconstruct compare alleles better evolution, following habitat, proceeds nature.