Genetic Variation in Population-Level Ecological Risk Assessment
In this chapter, the author reviews and synthesizes ecological applications of genetic information, and considers how genetic information can improve predictions of risks from environmental stressors to aquatic and wildlife populations. Genetic variation among individuals serves as the foundation for processes by which species and populations adapt to local conditions and evolve. Genetic loci under selection can have patterns that deviate from those of neutral markers, reflecting forces other than population history and demography. Neutral genetic variation has been used to describe and historical population condition — for example, size, richness, and uniqueness. Metapopulation ecology describes population interactions and dynamics associated with local dispersal patterns, which can sometimes be defined genetically. Understanding adaptive shifts in response to toxicants at the genetic level requires information about fitness, the genes underlying adaptive shifts, and the impact of population processes, such as gene flow, on the rate of adaptation.