In many animal species, females select mates according to visual signals—showy plumage, courtship displays, etc. The detailed study of the mechanisms of such sexual selection is often hindered by the difficulty of obtaining sufficient sample sizes or by the compound effects of several signals operating simultaneously. Künzler and Bakker have developed computer animations of male stickleback fish to study female responses. In virtual males, a single trait can be varied while others are held constant, and the experiment can be repeated indefinitely. Female three-spined sticklebacks were exposed to virtual males that varied in size, throat coloration, and courtship display, revealing which of the traits—in isolation and in combination—elicited the most enthusiastic response. Sexual selection is a powerful evolutionary force, and virtual-imaging technology promises to open new channels for its investigation. — AMS
Behav. Ecol.12, 681 (2001).