title: The ultimate and proximate mechanisms driving the evolution of long tails in forest deer mice.
abstract: Understanding both the role of selection in driving phenotypic change and its underlying genetic basis remain major challenges in evolutionary biology. Here, we use modern tools to revisit a classic system of local adaptation in the North American deer mouse, Peromyscus maniculatus, which occupies two main habitat types: prairie and forest. Using historical collections, we find that forest-dwelling mice have longer tails than those from nonforested habitat, even when we account for individual and population relatedness. Using genome-wide SNP data, we show that mice from forested habitats in the eastern and western parts of their range form separate clades, suggesting that increased tail length evolved independently. We find that forest mice in the east and west have both more and longer caudal vertebrae, but not trunk vertebrae, than nearby prairie forms. By intercrossing prairie and forest mice, we show that the number and length of caudal vertebrae are not correlated in this recombinant population, indicating that variation in these traits is controlled by separate genetic loci. Together, these results demonstrate convergent evolution of the long-tailed forest phenotype through two distinct genetic mechanisms, affecting number and length of vertebrae, and suggest that these morphological changes-either independently or together-are adaptive.
authors.affiliation: Howard Hughes Medical Institute, Department of Organismic and Evolutionary Biology, Department of Molecular and Cellular Biology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, 02138.
authors.forename: Evan P
authors.initials: EP
authors.lastname: Kingsley
authors.affiliation: Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, United Kingdom.|Current Address: Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Panamá, República de Panamá.
authors.forename: Krzysztof M
authors.initials: KM
authors.lastname: Kozak
authors.affiliation: School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; Swiss Institute of Bioinformatics, Lausanne, Switzerland and School of Life Sciences, Arizona State University, Tempe, Arizona, 85287.
authors.forename: Susanne P
authors.initials: SP
authors.lastname: Pfeifer
authors.affiliation: Burke Museum and Department of Biology, University of Washington, Seattle, Washington, 98195.|Current Address: US Fish and Wildlife Service, Ventura Field Office, 2493 Portola Road #B, Ventura, California, 93003.
authors.forename: Dou-Shuan
authors.initials: DS
authors.lastname: Yang
authors.affiliation: Howard Hughes Medical Institute, Department of Organismic and Evolutionary Biology, Department of Molecular and Cellular Biology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, 02138.
authors.forename: Hopi E
authors.initials: HE
authors.lastname: Hoekstra
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004272:DNA, Mitochondrial / Q000235:genetics; D065928:Forests; D065948:Grassland; D009656:North America; D010542:Peromyscus / Q000033:anatomy & histology* / Q000235:genetics*; D010641:Phenotype; D058974:Phylogeography; D017422:Sequence Analysis, DNA; D013623:Tail / Q000033:anatomy & histology*
chemical_list: D004272:DNA, Mitochondrial
keywords: Caudal vertebrae; Peromyscus maniculatus; convergence; local adaptation; parallel evolution; skeletal evolution