Lecture 28 Flashcards
(32 cards)
what is behavior?
an externally coordinated response to external stimuli
how does behavior evolve?
just like any other phenotype, includes variation, heritability and an influence on fitness
what do behavioral studies include?
artifical and wild settings
what do proximate (causing) studies of behavior focus on?
proximate studies of behavior focus on how a behavior is elicited
what do ultimate studies of behavior focus on?
ultimate studies of behavior focus on why particular behaviors have evolved as adaptations
is behavior limited to animals with nervous systems? explain
no, behavior is not limited to animals with nervous systems. we can see behavior in carnivourous plants such as venus fly trap
do genes influence behavior?
- yes
- as seen in the fox experiment: bred docile foxes with other docile foxes, and this helped to uncover the genetic basis of agression and tamness in foxes
what are the four kinds of social. behavior
- mutual benefit: positive behavior for both, should evolve quickly, positive frequency dependent selection
- selfishness: positive for actor, should also be easy to evolve, most behavior is selfish
- altruism: positive for recipient but negative for actor, this is a conundrum for scientists
- spite: bad for both, evolutionary unstable, won’t be maintained since not good for both
what is a darwinian paradox in terms of social behavior
altruism, as it is inconsistent with individual level selection
what is the general definition of game theory?
when social conditions determine behavioral strategies (what behavior should you adopt based on the social conditions)
what is the evolutonary stable strategy?
a behavior that when adopted by the majority of the population cannot be invaded by another strategy.
when does frequency dependent selection occur in game theory?
frequency dependent selection occurs when the fitness of an individuals depends on the relative frequency of other phenotypes in the population. so essentially is is what strategy you play depending on the other strategies of the people you are playing with
What are the 3 ffrequency dependent selection situations?
- positive frequency dependent selection: the majority has the advantage
- negative frequency dependent selection: the minority has the advantage, which promotes genotypic and phenotypic diversity
- Frequencies can exist where all phenotypes have the same fitness
do nicer strategues win or lose over a long period of time? what is this referred to as?
nicer strategies win over a longer period of time, whic is referred to as altruism spread “Tit for Tat”
What is needed for cooperation (doing a behavior to help the other person)
reciprocity, some sort of benefit in their fitness (whether that be direct or indirect fitness for their relatives)
what is the phenomenon of altruism?
- decreases the fitness of the individual possesing the trait (the cost to altruism) and increases the fitness of one or more other individuals (the benefit to altruism)
- the individual possessing the altruistic trait is the donor/helper/actor. the helpers fitness is lowered by the altruistic trait
- the beneficiary of the altruism is called the recipient. the recipients fitness is enhanced by the altruistic trait
why does helping behavior (altruism) evolve?
- to help closely related relatives
- kin selection
what is direct fitness
an organisms own reproductive success (survival x fecundity(
what is indirect fitness
reproductive success of genetic relativevs facilitated by an individuals actions
what is inclusive fitness
direct fitness + indirect fitness
what is kin selection
selection arising from the indirect benefits of helping relatives
what is hamilton’s rule and how does it explain altruism?
- hamiltons rule explains altruism
- benefit and cost are measured in units of suriving offspring
how do you calculate hamilton’s rule?
B=benefit to recipient=(fitness of helped individual)-(fitness of unhelped individual)
C=cost to helper=(fitness when helper does not help recipient)-(fitness of the helper when they help recipient)
r=relatedness of recipient to helper
altruism evolves when: rB>C
what is the relatedness of offspring to parent
0.5
