Question 1

Which of the following is NOT an example of frequency-dependent selection?

Accepted Answer

Frequency-dependent selection involves the fitness of a phenotype depending on its frequency relative to other phenotypes in a given population. Choices A, B, and C all describe scenarios where the success or survival of an organism is influenced by the prevalence of certain traits or behaviors, which aligns with the concept of frequency-dependent selection. Choice D, however, describes a situation where the lack of antipredator skills in New Zealand birds is not related to the frequency of those traits within the population but rather to historical isolation from predators, making it not an example of frequency-dependent selection.

Question 2

Sometimes traits that we observe in a population appear not to be particularly adaptive. How is it possible for nonadaptive traits to exist?

Accepted Answer

Nonadaptive traits can exist due to a variety of reasons. They might be linked to adaptive genes on the same chromosome, making them difficult to eliminate through natural selection. Pleiotropy, where a single gene affects multiple traits, can also result in nonadaptive traits if the gene has at least one beneficial effect. Additionally, gene flow, the transfer of genes from one population to another, can introduce nonadaptive traits into a population.

Question 3

An evolutionarily stable strategy (ESS) would be described as

Accepted Answer

An evolutionarily stable strategy (ESS) is frequency dependent, meaning its effectiveness depends on how common or rare it is within a population. This contrasts with frequency-independent strategies, which are effective regardless of their prevalence.

Question 4

An evolutionarily stable strategy (ESS) is

Accepted Answer

An evolutionarily stable strategy (ESS) is one that, when adopted by a majority of a population, cannot be outcompeted or replaced by an alternative strategy. It ensures that individuals using this strategy will have a reproductive or survival advantage, making it stable over evolutionary time.

Question 5

Brockmann and others (1979) studied female digger wasps' (Sphex ichneumoneus) alternative nesting strategies (digging her own nest or entering an existing burrow) and their outcomes. They found no significant difference between the reproductive successes of wasps using a dig strategy and wasps using an enter strategy. This indicates that the nesting strategies are

Accepted Answer

A mixed Evolutionarily Stable Strategy (ESS) implies that multiple strategies coexist in a population because they yield equivalent fitness outcomes. Since both digging and entering strategies result in similar reproductive success, they can coexist without one outcompeting the other, characterizing a mixed ESS.

Question 6

Male side-blotched lizards (Uta stansburiana) come in three coat colors, orange, yellow, and blue. Orange throated males are very aggressive and defend large territories that include several females. Yellow throated males are "sneakers" who have no territory of their own, but mate covertly with unguarded females on an orange male's territory. Blue throated males defend territories that are big enough to hold only a single, well-guarded, female. In this mixed ESS

Accepted Answer

This is an example of a rock-paper-scissors dynamic where yellow beats orange by sneaking, blue beats yellow by guarding, and orange beats blue by overpowering.

Question 7

Negative assortative mating preserves genetic variation in a population by producing a situation in which

Accepted Answer

Negative assortative mating refers to a mating pattern in which individuals with dissimilar phenotypes are more likely to mate, effectively meaning "opposites attract." This increases genetic diversity within a population by encouraging the combination of different genetic materials.

Question 8

The hypothesis that territoriality in funnel-web spiders is adaptive was most clearly supported by the finding that

Accepted Answer

Territorial spiders having 13 times the reproductive potential of nonterritorial spiders directly supports the idea that territoriality is adaptive by showing a significant benefit in terms of reproductive success, which is a key measure of evolutionary fitness.

Question 9

Tinbergen observed a seemingly nonadaptive behavior in black-headed gulls (Larus ridibundus), i.e., that the gull parent does not immediately remove broken eggshells from the nest. Further observations revealed that

Accepted Answer

A) Delaying shell removal allows chicks to dry and become less attractive to cannibalistic neighbor gulls, thus reducing predation and increasing chick survival rates.

Question 10

Tinbergen painted some black-headed gull eggs white and then compared the predation rate on white eggs against that on natural, camouflaged, eggs. This is an example of which of the following approaches?

Accepted Answer

Tinbergen's approach of painting eggs and comparing predation rates between altered and natural eggs is an example of the experimental method, where variables are manipulated to test their effects on outcomes, in this case, the effect of egg color on predation rates.

Question 11

We can assume that related species will have inherited some common genes because they have a common ancestor. If they live in different ecological conditions, however, they have experienced different selection pressures. Observed differences in their behavior, therefore, may be due to natural selection. This argument provides the rationale for which approach to the study of adaptiveness?

Accepted Answer

The comparative method involves comparing different species that have evolved from a common ancestor but have adapted to different environments. This approach helps in understanding how natural selection has shaped behaviors differently in related species due to their distinct ecological conditions.

Question 12

The comparative approach identifies correlations between traits and ecological variables. This means that

Accepted Answer

The comparative approach involves comparing traits of related species in different ecological settings to identify correlations with ecological variables, suggesting that differences in behavior may be due to natural selection. When these correlations can predict behavior in unstudied groups, the findings become more convincing, encompassing all the options provided.

Question 13

The strongest conclusions regarding the role of phylogeny in adaptations would come from

Accepted Answer

The strongest conclusions about the role of phylogeny in adaptations can be drawn from examining multiple species with different evolutionary origins found in various environments. This approach allows for the comparison of how different lineages adapt to environmental challenges, providing clear insights into the role of evolutionary history in shaping these adaptations.

Question 14

Antler size, age, and body size are all correlated with reproductive success among red deer (Cervus elaphus) stags. When appropriate statistical controls were applied, it was determined that ____ was NOT the primary factor.

Accepted Answer

Antler size, when statistical controls for age and body size are applied, is not the primary factor influencing reproductive success among red deer stags. Age and body size have more significant impacts on reproductive success.

Question 15

A 30-year-long study by Grant and colleagues (1981; 1984) determined that during periods of drought, medium finches with medium beaks produced more offspring, while during rainy years birds with smaller beaks had the advantage. This study is an example of which method?

Accepted Answer

The study by Grant and colleagues involved observing and recording the natural behavior and characteristics of finches in their natural habitat over a long period. This approach is known as monitoring in the field, where researchers collect data without manipulating the environment or the subjects being studied.

Question 16

What is the major problem associated with the application of optimality theory to the study of animal behavior?

Accepted Answer

The answer of What is the major problem associated with...

Question 17

When animals have displayed behaviors that appear very complex, behaviorists have generally concluded that

Accepted Answer

Complex behaviors in animals are often interpreted by behaviorists as the result of following simple strategies rather than evidence of high cognitive abilities or conscious decision-making processes.

Quiz 4: Natural Selection and Behavior