Habitat selection and evolutionary strategies in Drosophila: an invited address.

There is an association among resource utilization divergence, habitat selection, and taxonomic divergence in the genus Drosophila. Given permissive conditions of temperature, humidity, and light intensity, an enormous vairety of resources is used in a diversity of habitats. These resources are considered in the cosmopolitan and endemic Australian fauna, providing evidence for habitat selection in the laboratory and field. Lek behavior in picture-winged species of subgenus Hirtodrosophila, a case of parallel evolution with lek behavior in subgenus Drosophila in Hawaii, is discussed in detail. Other examples of habitat selection discussed concern behavioral reactions of larvae to alcohol and other metabolites and the avoidance by adults of extreme physical environments. Evolutionary strategies involved in habitat selection are considered at various taxonomic levels in Drosophila. These considerations show that it is essential to relate results from laboratory studies to natural environments in order to explore the genetics of habitat selection.