An example of interlocus sexual conflict is the expression of accessory gland proteins by males during mating, which negatively affect female fitness.
For example, a female may diminish detrimental consequences of being subjected to male accessory gland proteins during mating by waiting longer to re-mate, or she may develop an opposite physical adaptation of her reproductive tract.
Intralocus sexual conflict occurs because many phenotypic traits are determined by a common set of genes which are found and expressed in both male and female individuals.
For example, phenotypic traits such as body size, diet, development time, longevity, and locomotory activity are typically positively genetically correlated between sexes.
Intralocus conflict then originates in the second phase when a change in physical or social conditions causes intense selection on that trait in males and/or females, and both sexes are displaced from their optimum.
[13] A good example of intralocus sexual conflict can be seen in humans, regarding the selection pressures on height that varies between sexes.
In nature, a negative correlation between the height of a woman and her reproductive success has been seen, with selection favoring relatively shorter women.
These findings show that intralocus sexual conflict over a physical trait, such as height, can have an effect on Darwinian fitness in humans.
[10] Intralocus genetic differences between males and females have been identified in a variety of fish species using RAD sequencing, including gulf pipefish[18] and deacon rockfish.
[19] It has been hypothesised that some of the loci in deacon rockfish may be examples of intralocus sexual conflict but their function and evolutionary significance is currently uncertain.
By doing this, genes that are negatively selected may evolve sexually dimorphic traits that encourage sex- specific optima.
In this mechanism, the sex of an organism will ultimately decide the final form of the protein that is created from a shared coding region within a set of genes.