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

Abstract

Molecular genetics provides data with temporal and spatial scales unavailable from other disciplines. Patterns of genetic diversity are influenced by adaptive, environmental, and stochastic factors. The rate of change in genetic markers allows investigations of diversity on temporal scales resulting from recent history (hundreds of years) to deep evolutionary time (millions of years). Cryptic spatial population structure is often revealed by molecular markers. Phylogeographic analysis of genes within populations can unite demographics with glaciation, uplift, climatic shifts, or major floods. Historically, the application of genetic markers has been largely limited to analyses of gene frequencies and patterns of diversity. The consequences of genetic rarity are controversial in relationship to endangerment or patterns of extinction. However, it is widely recognized that genes reflect a species' evolutionary past and represent the raw material underlying the diversity of biological expression throughout a species' range. DNA provides the architecture necessary for a species' adaptation and future survival. Conservation of this evolutionary legacy is important considering anthropomorphic manipulation of a species and the environment upon which it depends. In this paper I investigate evolution and genetic variation in Atlantic salmon (Salmo salar) based on the current literature. I further discuss conservation and restoration questions using molecular markers.