Evolutionary ecology includes community structure, trophic interactions, life-history tactics, and reproductive modes, analyzed from an evolutionary perspective. Freshwater environments impose spatial structures on populations, facilitating genetic and phenotypic divergence. Freshwater systems have often featured in ecological research and population biology. This text contains information on diverse freshwater taxa, with a mix of critical review, synthesis, and case studies. Examples from the bryozoans (now the ectoprocta), rotifers, cladocerans, molluscs, teleosts, and others, are studied in order to cover issues of evolutionary ecology in detail, and this book can be used as a source of ideas, case studies and open problems in this field. It should be of relevance to students and researchers in ecology, limnology, population biology, and evolutionary biology.