Ecological Characters and Phylogeny

Theoretical considerations often suggest that ecological parameters of insects evolve rapidly, so that close taxa differentiate or distant ones converge. Phylogenetic analysis provides evidence both for and against such hypotheses. Ecological data may be incorporated into phylogeny reconstruction or evaluated against existing cladograms. Explicit statements regarding definition of alternative character states and direction of state change can trace evolution through hypothetical ancestors, establishing the most parsimonious explanation for observed data. Recent appliCations of these methods suggest that, wheh properly used and defined, ecological traits accurately reflect phylogeny. Some statistical methods aspire to factor out phylogenetic linkage from the correlation between traits, but such techniques are problematic. This review offers examples to demonstrate these general points and to stress the importance of a phylogenetic perspective in insect ecology. Specific issues examined within the cladistic framework include the phylogeny of insect-host plant interactions and the evolution of mimetic and mutualistic relationships.