Sexual conflict
It occurs in a species when what benefits the females is different from what benefits the males.
The word 'benefit' here means 'what benefits the reproduction of the female's (or male's) genes. It is expressed as a difference in biological fitness.
The conflict can lead to an evolutionary arms race between males and females. It has primarily been studied in animals, though it can in principle apply to any sexually reproducing organism, such as plants and fungi.
Fundamental difference of interest
In sexual reproduction there is, from the point of view of evolution, a fundamental difference of interest between males and females. This difference of interest plays out differently in different species.
- Males
Their interest is to mate with a large number of completely faithful females, thus spreading their genes widely in the population.
- Females
Their interest is to mate with a large number of fit males, thus producing a large number of fit and varied offspring.
"A hormone called 'sex peptide'...[1]92
- The same set of alleles in males and females may have different optima: they are expressed differently in the sexes. A classic example is the human pelvis, where females need larger hips for childbirth. A narrower hip size is better for locomotion.
The genes that affect hip size must reach a compromise that is at neither the male optimum nor the female optimum. In some cases, the loci involved are expressed differently in males and females. Evidence indicates that intralocus conflict is important in the evolution of many traits.[2] - may lead to antagonistic co-evolution, in which one sex (usually males) evolves a favorable trait which is countered by a trait in the other sex.
For example, male bean weevils (Callosobruchus maculatus) have spiny ia.
However, this damages the female and reduces her fitness.[3]
Some regard as a subset of sexual selection (which was traditionally regarded as mutualistic), while others suggest it is a separate evolutionary phenomenon.[4]
Related pages
References
- ↑ Schilthuizen, Menno 2001. Frogs, flies and dandelions: the making of species. Oxford University Press. ISBN 019850392X
- ↑ Arnqvist G. and Rowe L. 2005. Princeton University Press, Princeton New Jersey
- ↑ Crudgington H. & Siva-Jothy M.T. 2000. Nature. 407: 855-856.
- ↑ Lodé, Thierry 2006. La guerre des sexes chez les animaux. Jacob, Paris. ISBN 2738119018
[[Category:Evolutionary biolog