BIOL354: Animal Behavior: Exam 3 Review: Iowa State University: Fall 2019: Dr. Amy Toth

Define: Altruistic Behavior

A social behavior that has a cost to the actor but a benefit to the recipient

What are the three characteristics a population needs to exhibit to be considered eusocial?

1. Overlapping generations

2. Cooperative brood care

3. reproductive and non-reproductive castes

In a eusocial group, individuals in the worker caste (always/never) reproduce.

never

Define: Kin selection

natural selection applied to kin; OR when an animal behaves in ways that add to the fitness of its relatives.

Define: inclusive fitness

a measure of an individuals fitness based on...

1. the individuals own offspring

2. the contribution it makes to the reproductive success of it's genetic relatives.

What does evolution act first and foremost on?

Genes.

It is thought that organisms are simply machines which act only to maximize the number of ________ created through reproduction.

selfish gene copies

How does altruism tie into this "selfish gene" theory?

because copies of our genes exist in closely related organisms, it is beneficial to ensure reproduction of those genes regardless of which individual they are in.

Why did J.B.S. Haldane say that he would lay down his life for two brothers or eight cousins?

Because we share half our DNA with a sibling and an 8th of our DNA with cousins, thus he could preserve his entire genome (theoretically) by having two living brothers or 8 living cousins.

Define: Coefficient of relatedness (represented as r)

The probability that individuals share alleles that are identical by common descent. (i.e. a calculated estimate of how many genes two individuals share based on their relationship with the other organism being compared).

What measure of relatedness does coefficient of relatedness use?

Percentage (e.g. cousins are related 1.25 or 12.5%)

numbers does r range from?

0 to 100 (again working in percentages)

How closely related (percentage) are siblings to one another?

50%

How closely related is a child related to one parent (doesn't matter which parent)

50%

How related are first cousins to one another?

12.5%

How related is an individual to their aunt or uncle?

25%

How related are you to your grandparent?

25%

Kinship (promotes/inhibits) prosocial behavior and (promotes/inhibits) antisocial behavior

Promotes; inhibits

Hamilton's rule

The principle that for natural selection to favor an altruistic act, the benefit to the recipient, devalued by the coefficient of relatedness, must exceed the cost to the altruist.

What is the formula for Hamilton's rule?

rB>C

what does the r stand for in rB>C?

relatedness between actor and recipient (e.g. 0.125 NOT 12.5%)

what does the B stand for in rB>C?

fitness gained by recipient

what does the C stand for in rB>C?

fitness cost to actor.

C = The chance of you drowning to save your sibling is 0.10 times future offspring (2 in this case)

B = You and your sibling will both have 2 offspring in the future but don't have offspring at the moment (and no, neither of your wifey-poo's are pregnant at the moment either).

r = 0.5 because you are siblings.

What would this equation look like?

(0.5 x 2) > (0.1 x 2)

For altruism to be favored, rB needs to be larger than C. Would altruism be favored in the example on question 24?

Yes because Rb= 1 and C= 0.2.

Hamilton's rule is a theoretical calculation to try and predict when altruism will happen in nature. Over generations, selection is most likely to favor what outcome with regards to Hamiltons rule?

Behaviors that move towards equality balance of rB and C

What does E.O. Wilson ask about nature in his book "Sociobiology published in 1972"?

If biology could abide by mathematical laws in the same way physics does (Hamiltons law as an example).

What problem does E.O. Wilson's idea of a mathematical model of altruism run into?

It's difficult to measure fitness gained by the receiver of altruism and lost by the altruistic individual. Needs to know lifetime success of both individuals without them having their lives complete yet.

We don't see animals sacrifice themselves for the species, but we do see eusocial animals sometimes sacrifice themselves for the good of the _____.

colony

What is interesting in eusocial insects regarding relatedness?

They are haplodiploids

Define: haplodiploidy

a sex-determination system in which males develop from unfertilized eggs and are haploid, and females develop from fertilized eggs and are diploid

In a haplodiploid systems, how related are mothers and daughters?

50 percent (or r=0.5)

In a haplodiploid systems, how related are full sisters?

75 percent (or r=0.75). Sometimes called "supersisters"

In a haplodiploid systems, how related are brothers and sisters?

25 percent (r=0.25)

In a haplodiploid systems, males do not have _____ but do have _____.

fathers; grandfathers

Who are the workers in eusocial hymenoptera colonies?

Females

In eusocial hymenoptera colonies, what is the males role?

reproduction (males don't mate with queen of own colonies, they leave to find unrelated queens to mate)

haplodiploidy hypothesis

the extremely high relatedness produced by haplodiploid systems favors the evolution of cooperation

If a queen in a eusocial hymenoptera colony mates with many males, what happens to relations with sisters?

it goes down significantly (r can begin to approach 25 percent)

Define: Monandry

queen mates with one male

If monandry was present in ancestral forms, haplodiploidy could have facilitated the origin of what?

eusociality

Recap of all this

ancestral hymenopterid females were monandrous (only mated with one male). They were also haplodiploid making the colony members incredibly closely related to one another which is thought to have been the origin of eusociality. Once eusociality was evolved in full, its thought that females began mating with multiple males (for reasons we aren't going into in this chapter) creating the present day condition of colonies.

In the phylogenetic tree of Hymenoptera, does monandry appear to be ancestral or is polyandry?

monandry is ancestral. Polyandry appears to have evolved several times.

Differences in relatedness between one's self and parents, or one's self and sibling leads to ______.

Conflict

offspring should (take/give) as many resources as possible from/to their parents? Parents should (give/withhold) some resources to young.

take; withhold

Define: Phenotype matching models

individual 1 attempts to assess kinship of individual 2 by matching it against an internal template

What are the two ways that a template for kin recognition can come about?

1. Genetically

2. Learned

What example was used in class for kin recognition?

Cannibalistic spadefoot tadpoles recognizing kin by tasting them (this didn't matter if they had been starved.

Define: Major histocompatibility complex (MHC)

-Immunity gene that is extremely variable between individuals (is seen in humans that women prefer a partner with men that have a different MHC complex, and mice form commune with those similar in general)

Define: Rule of thumb models

When an animal uses a cue that is often correlated with kinship as a reliable (but not always accurate) indicator of kinship

What are the two rule of thumb models in kin recognition discussed in class?

1. Kin-differential spatial association

2. Kin-differential familiarization

Define: Kin-differential spatial association.

When gin are reliably found in a given place ("if its in my nest, it must be mine")

Define: Kin-differential familiarization

When social familiars are treated as relatives.

What is an issue that with kin differential spacial spatial association discussed in class?

Brood parasites such as the cookoo bird kicking out other birds eggs and laying their own.

Define: Cooperation

an outcome in which two or more interacting individuals receive a net benefit from their joint actions (despite the costs to each of the actions)

True or false: Cooperation only occurs between related individuals

false. cooperation happens most commonly between individuals but can occur between unrelated individuals and even different species.

By definition, altruism comes at a cost to the (actor/receiver) of the altruistic act

actor

What are two reasons why unrelated individuals may cooperate?

1. The immediate cost of not cooperating is high (e.g. cooperation is socially enforced).

2. Not cooperating over time is costly (jerks may win in the shortrun but not in the longrun because people stop trying to cooperate with them)

Define: Reciprocal altruism

altruistic exchanges between individuals such that an altruistic act by animal 1 toward animal 2 is returned by an altruistic act by animal 2 towards animal 1 (you scratch my back and I'll scratch yours)

Define: Allogrooming

grooming another individual

Explain: Prisoner's Dilemma

a scenario in which two players can either cooperate or defect specifically where the payoff for a single player defecting is larger than the payoff for both cooperating (temptation to cheat) there is a mutual cost for mutual defection, and a high cost for a lone cooperator (wont lie this is a super difficult concept to put into quizlet form, I recommend looking at the slides for it)

What factors are there to consider in the prisoners dilemma?

1. Temptation to cheat (T)

2. Sucker's lack of payoff (S)

3. Punishment for mutual defection (P)

4. Reward for mutual cooperation (R)

What must the prisoners relationship pay off be for it to hold true?

T>R>P>S

Evolutionary Stable Strategy (ESS)

strategy which, once established will persist

How is the prisoner's dilemma relevant to animals?

in social groups animals are faced with situations in which they must choose to cooperate or not.

What example was used in class to talk about reciprocity?

Vampire bats feeding others who didn't get food from the night before. They are most likely to show reciprocity with related individuals and those who they have previous social interactions with.

Why do we study game theory (prisoner's dilemma)?

helps to understand evolution of reciprocal altruism.

True or False: Byproduct mutualism may also explain some instances of cooperation when payoffs for cooperating are high and payoffs for defecting are low.

true

What is byproduct mutualism

when cooperation evolves as a consequence of the fact that the cost of not cooperating is so high that individuals will experience a huge and immediate penalty for not doing so

When is by product mutualism most likely to evolve?

In harsh environments (if you don't cooperate, you die)

True or false: Byproduct mutualism requires individual recognition.

false

What example was used for byproduct mutualism in class?

House sparrows doing a "chirrup" call upon finding food to call others over.

Byproduct mutualism is thought to operate on all of the following except

a) genes

b)individuals

c)groups within a species

d) species

d) species

Altruism for the good of the species. This is never true. How can you change one word to make the sentence true?

change species to group

True or false: group selection is accepted by all scientists

false: most don't believe it is valid. It's considered taboo by many

trait-group selection models

- Models used to understand cooperative behavior that consider selection acting at two levels-within-groups and between-groups

Within-group selection

acts against cooperation - individuals compete with one another

between group selection

- Can act for cooperation--groups can outcompete other groups

Between group selection in humans may account for what?

- War

- Genocide

- Tribalism

- Charity

- Religion

What is the main criticism of group selection theory?

Individuals are more evolutionary stable than groups. Dilution of selection will occur when groups are change or disintegrate.

Where do we see group selection that heavily supported?

eusocial insects (turtle ants that one ants job is literally to just be a door.

Define: Dyadic interactions

interactions between two individuals

What are the three types of interactions?

1. Polyadic interactions

2. coalition

3. alliance

Define: Polyadic interactions

interactions involving two or more individuals

Define: Coalition

when 2 or more individuals take cooperative actions against another individual or group

Define: Alliances

long term coalitions

What is coalition most commonly seen as?

within group fighting with an individual, often socially dominant, comes to the aid of another or breaks up a fight

often when fighting an opponent, male baboons will do what?

do a solicit display to enlist the help of another baboon, and if female is involved, coilated males may gain reproductive access. (may return favors as well)

Define: Mutualism

cooperation between species (interspecific)

(e.g. blowfish and anemones)

_____ can occur in many different types of animals.

cooperation

Define: Foraging

searching for and consuming food

What is search image theory?

When an animal has a search image in their mind and uses it to find their food. image becomes more detailed the more experience had. Often used to find cryptic prey

optimal foraging theory

Mathematical models that use "optimization theory" to predict various aspects of animal foraging behavior.

optimization theory

organisms will make choices so as to maximize some dimension of reinforcement

What four questions does optimal foraging theory ask?

1. What to eat.

2. how long to stay in a certain food patch.

3. How do nutrient requirements affect foraging?

4. How does variation in food supply affect decisions about what to eat.

When considering the "what to eat (prey choice) aspect, what are the factors related to it?

1. Encounter rate (how common is the food?)

2. Energy value

3. handling cost

define: Handling cost

time to eat it, risk associated with taking food.

If easy food with lower energy value is prevalent (e.g. rabbits), more dangerous prey items (gazelle) will not be chosen even though their energy value is greater.

What is the equation for profitability in prey choice?

Profitability = energy value/handling cost

What is considered when moving food patches?

quality of food patch, relative to other patches in the environment, distance between the patches, cost associated with switching patches

Marginal value theorem

A conceptual optimal foraging model proposing that an animal should stay in a food patch until the rate of energy gain in that patch has declined to the average rate for the habitat, then depart for another patch.