The Mating Mind

A MIND FIT FOR MATING 129
could be viewed as a different style of waste. Male humpback
whales waste their energies with half-hour-long, hundred-decibel
songs that they repeat all day long during the breeding season.
Male weaverbirds waste their time constructing ornamental nests.
Male stag beetles waste the matter and energy from their food
growing huge mandibles. Male elephant seals waste a thousand
pounds of their fat per breeding season fighting other elephant
seals. Male lions waste countless calories copulating thirty times a
day with female lions before the females will conceive. Male
humans waste their time and energy getting graduate degrees,
writing books, playing sports, fighting other men, painting
pictures, playing jazz, and founding religious cults. These may not
be conscious sexual strategies, but the underlying motivations for
"achievement" and "status"—even in preference to material
sources—were probably shaped by sexual selection. (Of course,
the wasteful displays that seemed attractive during courtship may
no longer be valued if they persist after offspring arrive—there is
a trade-off between parental responsibilities and conspicuous
display.)
The handicap principle suggests that in each case, sexual
selection cares much more about the prodigious magnitude of the
waste than about its precise form. Once the decision-making
mechanisms of sexual choice get the necessary information about
fitness from a sexual display, everything else about the display is
just a matter of taste. This interplay between waste and taste gives
evolution a lot of elbow room. In fact, every species with sexual
ornaments can be viewed as a different variety of sexually selected
waste. Without so many varieties of sexual waste, our planet
would not be host to so many species.
Evolving Better Indicators
The late 1990s have brought an ever-deeper understanding of
fitness indicators in sexual selection theory. Biologists such as Alan
Grafen, Andrew Pomiankowski, Anders Moller, Rufus Johnstone,
Locke Rowe, and David Houle have pushed the idea of conditiondependence
deeper into the heart of sexual selection, relating it to