L11 - Intraspecific correlation Flashcards
(16 cards)
what are the two options of how to interact and what do they depend on
defect or cooperate, defect is an ess if E(D,D)>E(C,D) or E(D,D) = E(C,D)= E(C,C), similar to dove, a cooperative population would eventually have a defect gene spreading, cooperation can only work thus if there is a punishment for cheating, thus cheating does not pay off
what is seen as the best strategy when encountering
Rapaport’s tit for tat - cooperate on the first meetinf and then copy partners previous behaviour
how does the common vampire bat example show a potential tft strategy
young bats prone to starvation because need to feed very often, individual is able to gorge 130% of prefeeding weight, reciprocation and retalitation inferred from past interactions, therefore there is a benefit of altruistic behaviour in future
what are other strategies of cooperation or defection that might beat TFT
generous tot - cooperate with certain probability after opponent has defected
win stay lose shift (cooperate on first move and afterwards repeat action of previous round if payoff worth it)
what did experiments on cooperation between rats show
some followed tft some did not, cooperation can occur if punishment present for defecting and if pay off is repeated
what is byproduct mutualism
altruism between non-kin, eg a call in the presence of a predator is meant for individual itself, but others benefit by being nearby
Meerkats: One stands guard on a rock while others forage. If it spots a predator, it gives an alarm call—warning others, but also helping itself avoid predation.
what is enforcement of cooperation in non-kin
cooperation by coercion or threat of punishment, gombe chimps hassle/beg others for food so it is shared, rhesus monkeys beat up those who dont share, differences in sexes (females dont get clocked for cheating and taking food)
what is kin selection
refers to the evolution of behaviors that favor the reproductive success of relatives, even at a cost to the individual’s own survival or reproduction
what is hamiltons rule in kin selection
altruism will only spead in the population by kin selection if rB-C>0
where r is coefficient of relatedness, b is extra number of offspring due to altruism, and c is cost of acts (number of future offspring not produced), thus it is mostly dependent on r and should be directed to close relatives
how is relatedness defined in kin selection
probability that an allele in individual A is identical by descent with one in individual B (so individuals have 50%, cousins will have 25%)
how does relatedness work in monandrous monogynous nests
females (workers and queens) diploid, so half mother and half father, males are haploid so all DNA from mother, because mother is diploid there is 50% chance that sisters share the same set, however 100% that they share the same from father (since he’s haploid), so she is 50% father and 25% mother (50% of 50%), brother would share 25% as it only has mothers, but a son would have 100% as it is haploid
how does relatedness work in polyandrous monogynous nests
most workers will be half sisters, therefore would only be 25% related to each other, thus nonqueen male eggs kill as they would have been more related to any males, which would skew cooperation/altruism, only queens eggs tagged not to be eaten
how can kin be recognized
through spatioal distribution, association/familiarity (imprinting), phenotype matching or armpit effect ( the ability of animals to learn and use their own phenotypes as reference for recognition of relatives)
what is the main cost of relying on spatial distribution to recognize kin
it is open to cheating (brood parasitism)
how does phenotype matching work and how does it work in peacocks
self matching cues to find those closely related, in peacocks half brothers lek together:
indirect fitness when mating with a relative, because genes get passed on, Even if a male doesn’t reproduce himself, helping a relative attract females boosts his inclusive fitness. So, males cluster with half-brothers to:
Increase chances one of them gets chosen
Gain from shared reproductive success, leks proven to be more related than they would by chance
how do female crickets avoid inbreeding
potentially using chemical cues like cuticular hydrocarbons (CHCs), female will avoid mating witht hose similar to her
If a female avoids a male that her sister mated with, despite never having met that male herself, it suggests she’s detecting kinship based on shared self-cues.
So even if the sister did mate with a genetically similar male (perhaps due to imperfect recognition), the focal female avoiding him afterward still shows a behavioural mechanism of kin avoidance.
