Application of Genetics to Taxonomy, Biology, Conservation, and Management

We systematically review genetic and genomic research on wild populations of mountain sheep (bighorn [ Ovis canadensis ]), thinhorn [ Ovis dalli ]). We begin with a brief history and explanation of methodological approaches, supported with a glossary. We synthesize genetic evidence for differentiation of these species from Old World species, previously and currently recognized subspecies, and lower-level phylogenetic divisions. We present a map estimating revised historical ranges for bighorn sheep subspecies. We then describe how genetics has been used for the estimation of population history, structure, connectivity, and demographics on ecological time scales, review long-term studies, address measures of genetic diversity and inbreeding, and how they have been and will be used in the management of indigenous, restored, or translocated populations. We review research on adaptive variation and the genetic basis of traits and other genetics-based tools for the study of mountain sheep including disease testing, gut microbiomes, and diet characterization. Finally, we consider recent developments or potential new directions including work on taxonomy, local adaptation, better measures of inbreeding depression, gene expression, and epigenetics.