Population genetics and the conservation and management of Atlantic salmon(Salmo salar)

Molecular genetics provides data with temporal and spatial scales unavailab le from other disciplines. Patterns of genetic diversity are influenced by adaptive, environmental, and stochastic factors. The rate of change in gene tic markers allows investigations of diversity on temporal scales resulting from recent history (hundreds of years) to deep evolutionary time (million s of years). Cryptic spatial population structure is often revealed by mole cular markers. Phylogeographic analysis of genes within populations can uni te demographics with glaciation, uplift, climatic shifts, or major floods. Historically, the application of genetic markers has been largely limited t o analyses of gene frequencies and patterns of diversity. The consequences of genetic rarity are controversial in relationship to endangerment or patt erns of extinction. However, it is widely recognized that genes reflect a s pecies' evolutionary past and represent the raw material underlying the div ersity of biological expression throughout a species' range. DNA provides t he architecture necessary for a species' adaptation and future survival. Co nservation of this evolutionary legacy is important considering anthropomor phic manipulation of a species and the environment upon which it depends. I n this paper I investigate evolution and genetic variation in Atlantic salm on (Salmo salar) based on the current literature. I further discuss conserv ation and restoration questions using molecular markers.