Parent Offspring Conflict Flashcards
what causes parent offspring conflict?
there comes a time when it is more profitable for parent to stop investing in a particular offspring, and devote its effor to production of additional offspring.
offspring want as much care as they can get. demand more than parents are willing to invest
there is disagreement in amount of resources given and for how long
parent offspring conflict theory
each individual wants to replicate its own genes. parents are equally related to all offspring, but each offspring is more related to itself than its siblings.
parents benefit from terminating care from a particular offspring even if that offspring would benefit from more care.
offspring are selected to be more selfish than parents may want them to be
parents benefit from care termination happening earlier than offspring would.
parent offspring conflict in defence
offspring want protection, but this is risky for parents
parent offspring conflict in feeding
offspring want more! begging
parents cant afford to spend too much time feeding offspring, need to feed themselves.
parent offspring conflict in clutch size
parents want as many offspring as possible
offspring want as few siblings as possible
parent offspring conflict in sex ratios
sometimes offspring will want more sisters or brothers than the parents do
maternal fetal conflict
fetal genes are selected to increase transfer of nutrients to fetus, and maternal genes are selected to limit transfers beyond a maternal optimum
ex. placenta secretes hormones that decrease mom’s insulin, to get more sugar to fetus. mom produces insulin, placenta produces insulin degrading enzymes
precocial young
young that are born developed (able to move, etc. )
highly mobile
lots of brown fat
can eat solids
altricial young
young born underdeveloped, and fully dependent on parental care
weaning conflict in guinea pigs
moms are in charge of when weaning occurs, the pups want to nurse for longer.
time nursing decreases, and there’s no difference depending on pup’s age or stage of development. the mother decides shes had enough at a certain time, and thats it.
significant weaning masses, oldest pups heaviest
begging strategies
posture, calling, jostling and display bright mouths.
is begging an honest signal? does mouth colouration affect the amount of food a chick gets?
begging is an honest signal for young chicks because it is costly to produce, since it is difficult for chicks to get blood flowing to the mouth to produce this colour. Hungrier chicks had redder mouths. also, it is energetically costly and may attract predators. Excessive begging has been found to slow growth.
colouration affects the amount of food a chick gets. added red food colouring to mouths, and found that when the large chick is hungry, they get much more attention.
when does it make sense to feed the larger chick?
when the environment is poor, some chicks will likely die. parents feed offspring in best condition since its a safer bet they will survive. offspring are selected to signal quality
when does it make sense to feed the smaller/worse chick?
when the environment is good and is unlikely any chick will die, the parent will feed the worse offspring to “catch them up” to their siblings. offspring are selected to signal need.
