Question 1

What evidence did Herczeg, Gonda, and Merilä (2009) use to suggest that sticklebacks suffer a cost of sociality?

Accepted Answer

Herczeg, Gonda, and Merilä (2009) found that sticklebacks raised in groups had lower growth rates compared to those raised alone, suggesting a cost of sociality due to potentially increased competition for resources or other social stressors affecting growth.

Question 2

Social queuing refers to which of the following?

Accepted Answer

Social queuing refers to the process by which individuals can move up in dominance rank over time within a social hierarchy.

Question 3

Selection for behaviors that increase the fitness of relatives characterizes which of the following?

Accepted Answer

Kin selection refers to the evolutionary strategy that favors the reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction. This concept explains how behaviors that benefit related individuals can evolve through natural selection.

Question 4

Based on Hamilton's rule, an individual is most likely to help which of the following?

Accepted Answer

Hamilton's rule states that an individual is more likely to help relatives with whom they share a greater proportion of genes. Siblings share on average 50% of their genes, which is typically higher than the genetic share with nieces, cousins, uncles, or grand-offspring, making them the most likely to be helped according to this rule.

Question 5

According to Paul Sherman's (1977) work, why do male Belding's ground squirrels rarely produce the first alarm call when a predator is nearby?

Accepted Answer

Male Belding's ground squirrels are less likely to produce the first alarm call because these calls are costly in terms of attracting predators, and since males are often surrounded by unrelated individuals, the evolutionary benefit of warning others (kin selection) is reduced.

Question 6

Hamilton's rule predicts that altruism can evolve under which of the following circumstances?

Accepted Answer

Hamilton's rule states that altruism can evolve if the benefit to the recipient (B), multiplied by the coefficient of relatedness (r), is greater than the cost to the altruist (C). This is mathematically represented as Br > C.

Question 7

In the haplodiploid genetic system, which pair of individuals is most closely rated?

Accepted Answer

In the haplodiploid system, sisters share, on average, 75% of their genes. This is because they receive all their father's genes (who is haploid) and share half of their mother's genes (who is diploid), making them more genetically similar to each other than to their parents or offspring.

Question 8

The habitat saturation hypothesis can explain which of the following?

Accepted Answer

The habitat saturation hypothesis suggests that cooperative breeding evolves when there are limited opportunities for individuals to establish their own territories, leading them to stay and help raise relatives' offspring.

Question 9

The prisoner's dilemma game illustrates why the evolution of cooperation is difficult. What can facilitate cooperation in this game?

Accepted Answer

Repeated interactions and reciprocity can facilitate cooperation in the prisoner's dilemma game by allowing players to build trust and establish a history of cooperative behavior, which can discourage cheating and promote mutual cooperation over time.

Question 10

Why is blood meal sharing in vampire bats considered to have evolved via reciprocal altruism?

Accepted Answer

Blood meal sharing in vampire bats is considered to have evolved via reciprocal altruism primarily because individuals share food with individuals from whom they have received food. This behavior fits the concept of reciprocal altruism, where an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar manner at a later time.
The key aspects of reciprocal altruism, as observed in vampire bats, include:
1. **Non-random sharing**: Vampire bats tend to share blood meals with specific individuals that have shared with them in the past, rather than sharing randomly. This suggests a tit-for-tat strategy, which is a fundamental component of reciprocal altruism.
2. **Cost and benefit**: While there is a cost to the donor in sharing a blood meal (reducing its own food intake), the benefit to the recipient (who might otherwise starve) is significant. The donor bats are more likely to receive food from others on days when they are unsuccessful in finding food themselves, which can be a critical survival factor.
3. **Memory and recognition**: Vampire bats demonstrate the ability to remember past interactions and recognize other individuals, which is necessary for reciprocal altruism to evolve. They keep track of who has shared with them and are more likely to share with those individuals in the future.
4. **Enforcement**: There is evidence that vampire bats enforce the reciprocal arrangement by punishing individuals who do not reciprocate. Bats that do not share blood meals may find themselves excluded from future sharing by others.
The other options provided do not adequately explain the evolution of blood meal sharing via reciprocal altruism:
a. Blood meal sharing occurs both in captivity and in the wild, and its occurrence in the wild is essential to the argument for reciprocal altruism.
c. There is a cost to blood meal sharing for the donor, as it gives up some of its food resources.
d. While cooperation between males and females may occur, reciprocal altruism specifically refers to the exchange of resources between individuals, which can occur regardless of sex.
e. Blood meal sharing in vampire bats does not only involve relatives; it can also occur between unrelated individuals, which is a key point in the argument for reciprocal altruism rather than kin selection.

Question 11

In the captive Japanese macaques studied by Schino, Polizzi de Sorrentino, and Tiddi (2007), consider a situation in which individual A was observed to help individual B. This behavior was correlated with which of the following?

Accepted Answer

The study by Schino, Polizzi de Sorrentino, and Tiddi (2007) found that helping behavior in Japanese macaques was correlated with reciprocal altruism, meaning that individual A was more likely to help individual B if B had helped A in the past.

Question 12

Consider three individuals A, B, and C. In the model of indirect reciprocity, individual A helps B because of which of the following?

Accepted Answer

In the model of indirect reciprocity, individual A helps B because A saw B help another individual (C) in the past. This is based on the principle that individuals are more likely to help those who have helped others, showcasing a form of social cooperation and reputation building within a community.

Question 13

Hamilton's rule assumes which of the following in order to explain the evolution of cooperative behavior?

Accepted Answer

Hamilton's rule explains the evolution of cooperative behavior through kin selection, which relies on the ability to discriminate between kin and non-kin to direct altruistic acts towards those who share a greater proportion of genes.

Question 14

What two factors are required for the evolution of cooperative breeding?

Accepted Answer

The answer of What two factors are required for the...

Question 15

Bateson, Nettle, and Roberts (2006) work indicates that humans appear to care about their reputation for altruism. What assumption about their protocol is required to draw this conclusion?

Accepted Answer

The answer of Bateson, Nettle, and Roberts (2006) work indicates...

Question 16

According to Hamilton's rule, which of the following are individuals more likely to help, given that providing help is costly: A) a first cousin or niece? B) a sibling or grandchild? C) a grandchild or nephew?

Accepted Answer

The answer of According to Hamilton's rule, which of the...

Quiz 16: Cooperative Behavior