Lecture 13 Flashcards
A helpful behavior that increases the direct fitness of the receiver, but lowers the giver’s direct fitness.
Altruism
C < (r)B
Hamilton’s rule - altruism equation
Parents can only give half of its genes to a child = 50% or .5
Degree of relatedness, r=.5
Parent to grandchild = .25
Share .5 with your full sib
Degree of relatedness
Female ground squirrels give alarm calls more often because they are surrounded by kin. Altruistic because it draws predator to them.
Animal example of altruism
When receiver of altruistic act then turns around and becomes the giver to the animal it received from. A helps B, then B helps A
Direct reciprocity
Vampire bats - regurgitate blood meals to other bats who are unable to feed, and in return expect to receive the same assistance when they need it
Animal example of direct reciprocity
When the giver of an act, gets help from a different individual other than the receiver of the act, A helps B, then C helps A
Indirect reciprocity
Strategy whereby an organism will help relatives survive and breed - sometimes at their own personal detriment.
Kin selection
Help kin over nankin, and help close kin over distant kin.
Two tenets of kin selection
Direct fitness and indirect fitness
Inclusive fitness
Have your own offspring
Direct fitness
Help offspring of blood relatives
Indirect fitness
When a behavior that may have had another purpose becomes more exaggerated, more stereotyped, and serves as an attention getting behavior
Ritualization
the interaction between animals of the same or different species where they strive to acquire the same limited resource, like food, water, territory, or mates, which can lead to a struggle or conflict between them as they compete for that resource
Competition
An area defended by an individual animal or social group of animals, from other conspecifics
Territorial behavior
- Physical fighting - common chimp
- Scent marking - olfactory, lemurs
- Auditory - singing warblers, howling wolves
- Visual - birds with visual bases, European wildcats sign-posts
Territorial behavior examples (need 2)
A social hierarchy that forms when animals interact.
Dominance hierarchy
Linear rank: male baboons, male common chimps
High or low rank: female baboons, female common chimps
2 types of dominance hierarchies
Rank can be based on body size/strength (red deer), who your parents are (female baboon), age (elephants), hormone levels (chickens
Types of dominance hierarchies and animal examples (need to know 2)
male in the middle who is hotshot, other males make him look good bc they are not as good in song and dance, so a helps b look good, when that one gets old and goes away, a moves in to be hotshot, and then c comes in to make him look good - inferior male makes look good
Animal example of indirect reciprocity
Animals that are competing for dominance rank - all acts of aggression are adaptive
can have payoff for winner, give submissive signal when one loses - if aggression
continues, aggressive posture, and submissive posture to show that it is over - otherwise
would continue and lead to death.
Role of submissive signals
Animal wakes up and has repertoir of behavior it can follow through - can act like
hawk, or could act like a dove. Waking up and being surrounded by hawks, not a
good day to act like a hawk, so act like a dove. Doesn’t mean you act like a dove
every day. If you wake up and are surrounded by doves, act like a dove because
you can take advantage of them. Decide what to do based on whether rivals are
present or not.
Hawk and dove game theory
1) the value of the resource (V), (2) the cost of fighting (C), and (3) the probability of encountering a Hawk or a Dove
Three conditions for hawk and dove game theory
Energetic taxing to go in for lethal attack - could lose, get injured, costs much in
time and energy.
If you contested all rivals - what if a rival wasn’t worth fighting, was of such low rank
that it’s not worth the time and energy - don’t get much benefit.
Could be distant
relative - don’t want to kill genes. Have to wait - act like hawk and dove - wait to gain advantage - be strategic.
Three reasons why animals don’t always set out to kill a rival
Polyandrous animals - females are big movers are shakaers - shore bird,
jacana bird, she has more muscle, beats up other females, and steals other males
wants more than one mate
Spotted hyena - females have heightened level of testosterone in order for them
to be fertile, they need to have feeding priority - evolved aggressive females, if they
didn’t have feeding priority, there would be no offspring
Examples of heightened female aggression
