Ecological Genetics: Introduction
Ecological genetics concerns the adaptation of the individuals in natural populations to their habitats. Thus, in order to fully understand the adaptations, the phenotypes of individuals must be related to the ecological context of the population and to the underlying genetic bases of those phenotypes. The interplay between ecology, phenotypes and genotypes is complex. For example, the structure of a population (effective size, system of mating, subdivision and gene flow) can influence not only the speed of a genetic response to an environmental change, but can constrain the nature of that response as well. If the latter is true, the genetic basis of adaptations may not always represent “optimal” solutions. Understanding the genetic basis of traits associated with fitness differences is therefore a fascinating challenge for ecological geneticists. Unfortunately in normal environmental conditions, differences in fitness traits are often associated with low heritabilities. However, in situations of environmental stress, adaptations have been studied which have a more clearly detectable genetic basis.