Lecture 8- Sexual conflict Flashcards
why are females more disposed to parental care
mating skew- for males, it is more beneficial to continue to mate
sperm competition- may end up caring for non-offspring due to this, so behaviour is avoided
how can parental care in females make sexual dimorphism stronger
stronger male sexual selection, possibly due to more sparse mating availability for females?
operational sex ratio
number of fertilisable females to sexually active males- generally male-biased due to longer times out of the mating pool for females
why does sexual conflict occur
reproduction is costly, and there can be conflicts of interest
some examples of sexual conflict behaviours
coercion
sexual cannibalism
mating duration
sperm allocation and utilisation
example of coercion
duck males drowning females, attempting to ‘overcome resistance’
example of sexual cannibalism
mantids eating all/part of a female before/during/after reproduction
example of interrupting mating
females pushing males off with hind legs, genital spines to make this impossible
example of conflict over sperm allocation
in hermaphrodites- both partners ‘want’ to be the male, end up manipulating the other partner via hormone-covered spines
copulation plugs so males can prevent other sperm from being used
example of more complex sexual conflict mechanisms
use of signalling proteins in drosophila to encourage sperm storage, ovulation, egg production etc in females (ovulin, which stimulates ovulation)
sexual tragedy of the commons vs strategic harm
female harm as collateral damage from male-male aggression
harm may not just be an accidental side effect, can be purposeful to discourage specific behaviours
what can lead to more complex reproductive organs
competition, due to sexually antagonistic coevolution
examples of female counteradaptations
spines, shields etc to help counteract force from males
