Exploitation of Female Preferences
It is also possible that the female receives no benefit by choosing a particular
mate, but rather that he is appealing to her preferences. For instance, stalk
eyed flies have eyes on stalks that are very far removed from their head. This
conveys no advantage to the male, but the females prefer to mate with
long-stalked males. Begun as a sort of genetic whim, the traits soon become
correlated and entrenched. If a female who prefers long stalks mates with a
long-stalked male, their sons are likely to be long stalked due to the father's
genes, and the females are likely to prefer to mate with long-stalked males due
to the mother's genes. Those females will likely mate with long-stalked males,
and are even more likely to have long-stalked sons because she carries
the long-stalk genes from her father as well. Another possibility is that males are
exploiting pre-existing, noncorrelated female sensory biases. For instance,
some male water mites mimic the vibrations of prey, which attracts females and
increases male mating success.