L14 - Sexual conflict Flashcards
(19 cards)
what is sensory exploitation and how does it affect female preference
male sexual ornament sarise beacuse males esploit pre existing biases in female sensory systems
what are the three hypothesis for this theory
absence of trait in ancestral condition within clade, females show to have a preference fo this trait and even species where trait absent have a preference for this trait
what is an example of a trait being present now but not existing in the ancestral state
nuptial gifts in gryllodes
how can a preference for the trait be shown
spermatophylax size and ampulla retention time positive correlation
what is an example of trait being absent but preference existing
nuptial gift being absent in gryllus integer but females left ampulla for longer if they received a nuptial gift
what are some costs to polyandry
predation risk, harm by males (coercion), disease spreading
what are some benefits to polyandry
reduce harm by males, replenish sperm stock, first mating insurance so find better mates, direct benefits (nutrition), indirect genetic, eg compatible genes
how does remating ensure reduction of inbreeding and increase in offspring genetic diversity
gryllus bimaculatus female will show post-copulatory preference for non-sibling male sperm
what are the different strategies through which males ensure paternity
mate concealment, mate guarding, ability of sperm to displace competitors, infanticide (destruction of rival zygotes), induced abortion
how does guarding prevent female from remating
male stands guard while female oviposits or prevents her from removal of spermatophore (eg in dragonflies and crickets)
how does sperm displacement work
penish shape may be adapted to remove other sperm
how does ejaculate size ensure paternity
ejaculate size bigger when mated in presence of a potential rival, number of transferred sperm will be higher
what is meant by sexual conflict (in terms of male X female)
males have adaptations which harm females, thus females adapt to reduce harm, forming antagonistic coevolution
how can dropsophila males prevent females from remating
protein plug (PEBII gene), seminal fluid also reduces female longevity
how can female adaptations to male harm be tested in drosophila
survivorship of females when exposed to wild-type males, if females raised in male biased environment, they will have higher survivorship, those form female biased environment will have no defense techniques
how can females fight against male parental insurances
ejection of sperm post copulatory, molecular defense through responisveness for seminal fluid f’protein - variation in binding affinity
what is traumatic insemination and how did females adapt to reduce harm
in bed bugs, males pierce body of female to transfer sperm, which leads to spermelage (hole) to evolve which lessens the harm, the male benefit is on the basis of last sperm precedence, evolution of hole increases fecundity and reduces harm
what is chaseaway selection and how does it apply to sexual selection
male trait evolved to exploit preexisting female bias but it harms females, which leads to females becoming pickier, which selects for males that habe an even more exaggerated trait
what is an example of water striders and female adaptations
Han and jablonski 2009 - female striders prefer waters with more predators to prevent getting harmed by males
