Adaptation, Physiological, Polychlorinated Biphenyls - analysis, Rhode Island, Gene Frequency, Genotype, Water Pollutants, Chemical - analysis, Genetic Variation, Animals, Water Pollutants, Chemical - toxicity, Polychlorinated Biphenyls - toxicity, Geologic Sediments - analysis, Enzymes - genetics, Massachusetts, Survival Analysis, Population, Smegmamorpha -...