Lack of a Correlated Response to Canalizing Selection in Drosophila melanogaster

Fourteen generations of selection were practiced for reduction in the difference in eye facet number at 20°C and 25°C in a stock of Drosophila melanogaster homozygous for the mutants Bar and Abruptex. A reduction in the difference in Bar facet number (canalization) at the two temperatures occurred, but a correlated response in Abruptex wing-vein interruption was not observed. This experiment supports the idea that each developmental system is under separate control.