Beauty is in the eye of the beholder: causes and consequences of variation in mating preferences.

To a large extent, the success of evolutionary ecology stems from its focus on individual variation and acknowledging that individuals vary in predictable ways. Sexual selection is probably the branch of evolutionary ecology that has received most interest in the past two decades. Paradoxically, progress has been hampered by not taking individual mating preferences into account. Now, researchers are starting to pay more attention to individual variation in preferences. This change in focus holds great promise for future advances in the study of sexual selection.