Drosophila Larval Foraging Behavior and Correlated Behaviors

Abstract

Correlated behaviors are important from an evolutionary viewpoint, especially if the correlations are genetic. Phenotypic correlations of behaviors do not necessarily reflect genotypic correlations, however, since they may also be the result of environmental factors or have a large environmental component (Hedrick 1982). It is for this reason that it is important not to use phenotypic correlations as the basis for evolutionary predications (for example, in predicting correlated responses to selection). Genetic analyses of phenotypic correlations are essential to our understanding of evolutionary processes. Two behavior patterns may be correlated genetically because they are influenced by a common set of genes (pleiotropy) or because they are controlled by different genes that are closely linked on the same chromosome (linkage). For example, suppose there exists a positive genotypic correlation between the activity rates of two behaviors. In the case of pleiotropy, there might exist a general activity factor that influences the rates of activity of the two otherwise discrete behaviors. In the case of linkage, two sets of genes would influence activity rates independently in each of the behaviors.