Nonlinearity and the importance of fluctuating asymmetry as a predictor offitness

Nachman and Heller recently suggested that previous estimates of the relati ve magnitude of fluctuating asymmetry in morphological characters have been biased because non-linear relationships between asymmetry and size hale no t been considered. This suggestion cannot generally be very important becau se (1) inclusion of a non-linear size term in regression models relating fi tness components to asymmetry does not change the general conclusion that a symmetry is an important predictor of fitness components, and (2) experimen tal studies uncoupling the relationship between asymmetry and size have gen erally found significant effects of asymmetry independent of body size on m ating success and locomotion.