Sexual selection is the term used to describe the selection driven by competition for a mate. This usually includes the "evolution" and descent of the varying features (secondary sexual characteristics) that are observed in offspring.
Species often select mates based on criterion such as ornaments (such as the peacock's plumage) or defense capabilities (such as antlers).
Sexual selection is considered a similar component of natural selection.
Problems With Sexual Selection
Using sexual selection as a theory for understanding and predicting behavior assumes certain "rational" preferences (i.e., the rational woman will prefer the man with larger muscles, deeper voice and more facial hair, or the rational male will select a woman he finds more sexually attractive).
The problem with this is, the preferences of human beings are not predictable. Bearded men are not always considered the most eligible for women to marry. These natural laws for attraction are largely ignored by many who are attracted to someone possessing fewer of the "preferred" characteristics.
Additionally, studying the science of attraction between men and women is not viable under the framework of naturalism because love, emotions and preferences are intangible and abstract.
Other Problems or Exceptions:
- It requires the simultaneous evolution of female traits and male preference.
- It largely ignores female sexual selection. "Although sexual selection theory has proved successful in explaining a wide array of male ornaments, the function of ornaments occurring in females is largely unknown. ... Traditionally, ornaments occurring in females have been considered as mere by-products of selection on the males".
- It can lead to traits which are actually detrimental to survival, such as bulky antlers on deer and moose, or the more colorful feathers of a peacock being a bigger target.
- Leaves unanswered questions, such as how the peackock got his tail.
- More flight than fancy? PhysOrg, April 5, 2007 Scientists from the universities of Exeter and Cambridge have turned a textbook example of sexual selection on its head and shown that females may be more astute at choosing a mate than previously thought.
- Argument: Evolution of sex
- The beauty of the peacock tail and the problems with the theory of sexual selection
- Darwin's Teaching of Women's Inferiority
- Gender scientists explore a revolution in evolution The Stanford Report, February 19, 2002
- Evolution: Do Bad Husbands Make Good Fathers? Current Biology, Volume 15, Issue 20, October 25 2005.
- The Gay Animal Kingdom Seed Magazine, June 7, 2006
- Reproductive social behavior: cooperative games to replace sexual selection Science February 17 2006: 965-969