ECOLOGICAL POPULATION-GENETICS - THE INTERFACE BETWEEN GENES AND THE ENVIRONMENT

We review recent studies in ecological genetics considering the way ge nes interact with the environment. Studies on morphological and allozy me polymorphisms continue to highlight problems in identifying selecti ve factors. Selection on allozymes as well as quantitative traits may only occur under specific conditions. Responses to toxins illustrate h ow adaptive changes can be based on major genes with polygenic modifie rs. Analyses of continuous variation in ecologically relevant traits s uggest low levels of heritable variation in some natural situations an d emphasize the importance of genetic interactions. It is still not cl ear if adaptive responses in quantitative traits tend to involve major or minor genes. There is some evidence for genetic tradeoffs among en vironments and life history traits. Low levels of genetic variation, t radeoffs, and gene flow may restrict distributions and habitats occupi ed by species, but their relative importance remains unclear.