Exam 3

Question 1

Data from the fruit fly experiment show that

Answer 1

heterozygosity decreases at a faster rate for a population size of 16 flies

Question 2

The neutral theory of molecular evolution, as developed by Kimura, posits that

Answer 2

functionally neutral mutations that become fixed in populations occur in much larger numbers than those that become fixed by natural selection

Question 3

Although most of the mechanisms of evolution are nonrandom, the one that is absolutely nonrandom is

Answer 3

genetic drift

Question 4

Which part of the Hardy-Weinberg would you expect to decrease if inbreeding occurs?

Answer 4

2pq

Question 5

What would be the frequency of AABBCC individuals form a mating of two AaBbCc individuals?

Answer 5

1/64 (1/4 x 1/4 x 1/4)

Question 6

An increase in the inbreeding coefficient, F, is likely to result in

Answer 6

reduced likelihood of heterozygotes being present in a population

Question 7

How can conservation practitioners avoid outbreeding depression?

Answer 7

By making sure that all breeding individuals form part of the same evolutionary lineage

Question 8

When genotypes at one locus of a chromosome are independent of genotypes at another locus of the same chromosome, the two loci are

Answer 8

in linkage equilibrium

Question 9

Which of the following can produce linkage disequilibrium?

Answer 9

genetic drift, selection on genotypes of more than one locus, and mixing two disparate populations, each of which is in linkage equilibrium

Question 10

Consider the case of a lethal recessive allele present in a natural population at low frequency (i.e q=0.05) and not conferring any fitness advantage to heterozygotes. How quickly will this lethal recessive allele become lost from the population?

Answer 10

Very slowly, because as q approaches 0, q/(1+q) will approach q

Question 11

Why is genetic drift more important in small populations?

Answer 11

Because sampling error is higher in small populations than it is in large populations

Question 12

You are studying genetic structure in a population of 16 Florida panthers, 10 males and 6 females. What is the effective population size, Ne, in this population?

Answer 12

Ne=4106/(10+6)=15

Question 13

the theory of neutral evolution describes

Answer 13

the ratio of alleles at a site in the absence of selection

Question 14

When dN>dS

Answer 14

scientists would reject the null hypothesis of neutral evolution because the number of replacement substitutions is greater than expected (there is positive selection)

Question 15

What were some of the consequences of inbreeding in IL populations of Greater Prairie Chickens?

Answer 15

low number of alleles, decreasing population size, and failure to reproduce.

Question 16

When genotypes at one locus of a chromosome are non randomly associated with the genotypes at another locus of the same chromosome, the two loci are

Answer 16

in linkage disequilibrium

Question 17

A principle advantage of sexual reproduction is that it

Answer 17

helps to recreate genotypes that are either rare or missing 13% in a population, but are favored by selection, reduces linkage disequilibrium, regenerates genotypes in the evolutionary “arms race” between parasites and hosts, breaks Muller’s ratchet, i.e it prevents the accumulation 20% of deleterious mutants.

Question 18

The differences between males and females of a species are called

Answer 18

sexual dimorphisms

Question 19

In general, when sexual selection is strong for one sex and weak for the other, we can predict that members of the sex subject to strong sexual selection will be ____, and members of the sex subject to weak sexual selection will be ____

Answer 19

competitive; choosy

Question 20

In hermaphroditic species, individuals _____

Answer 20

are simultaneously male and female throughout their entire lives

Question 21

The benefits of sexual reproduction include

Answer 21

purging of mutations

Question 22

Adam Jones and colleagues (2000) studied the mating behaviors of broad-nosed pipefish (Syngathus typhle) in a laboratory situation. For which sex is sexual selection a more potent evolutionary force?

Answer 22

Females

Question 23

Selection for the ability to successfully compete with members of their own sex to mate with opposite sex is termed

Answer 23

intrasexual selection

Question 24

Which of the following has NOT been observed as a trait of sperm competition?

Answer 24

All have been observed:
applying hormones that reduce a female’s attractiveness, the production of large ejaculates contianing many sperm, depositing a copulatory plug, and prolonged copulation during mating.

Question 25

Gage (1991) tested the hypothesis that under strong sperm competition, male fruit flies would produce the largest ejaculates. Which finding supports this hypothesis?

Answer 25

males allowed to mate alone produced 2 1/2 times less sperm than those mating in the presence of other males

Question 26

A prediction from Fisher's theory of sexual selection (the runaway process) is that

Answer 26

a correlation should exist among families between female preferences and male traits

Question 27

Experiments by Steven Tanner and colleagues (2000) with gray tree frogs demonstrated that female frogs preferentially mated with male frogs exhibiting

Answer 27

longer calls rather than shorter calls

Question 28

How can you detect an allele that is undergoing strong positive selection?

Answer 28

high frequency in population and high linkage disequilibrium

Question 29

A prediction from Fisher’s theory of sexual selection (the “runaway process”) is that:

Answer 29

a correlation should exist among families between female preferences and male traits

Question 30

The Florida Scrub Jay, endemic to the scrub habitat of central Florida, is characterized by which of the following behaviors?

Answer 30

cooperative breeding through alloparental care (fledglings remain in their parents' habitat for several years and help to rear young

Question 31

According to Hamilton's rule, how many nephews/nieces would a grandparent "need to save" for an altruistic act to be justified in terms of inclusive fitness?

Answer 31

4 b/c coefficient of relatedness is r=0.25

Question 32

which species concept refers to the ability of populations of organisms to interbreed?

Answer 32

biological species concept

Question 33

which mammal is eusocial?

Answer 33

naked mole rat

Question 34

A behavioral strategy once adopted by most of the members of a population, will sometimes be resistant to replacement by another behavioral strategy. This is known as

Answer 34

an evolutionary stable strategy

Question 35

If cheating can be such a successful behavioral strategy, how might slime molds remain cooperative?

Answer 35

Both kin recognition and inclusive fitness are plausible explanations

Question 36

The creation of new combinations of alleles, as a consequence of sexual reproduction with meiosis is called

Answer 36

genetic recombination

Question 37

Which hypothesis has been proposed to explain the evolution of eusociality?

Answer 37

the haplodiploidy hypothesis, the ecology/life history hypothesis, and the origin of nesting behavior

Question 38

Which of the following is the best estimate of effective population size (Ne) in a population of sea lions with 20 adult males and 10 adult females?

Answer 38

Using the equation Ne = (4N_♂ N_♀)/((N_♂+N_♀) ), Ne = 800/30 ~ 27 sea lions

Question 39

Which of the following is NOT true of linkage disequilibrium:

Answer 39

Linkage equilibrium (D = 0) is attained in one generation of random mating.

Question 40

Consider two loci (locus 1 with alleles A and a, and locus 2 with alleles B and b) with allele frequencies p = p(A) = 0.4 and s = p(B) = 0.7. What are the expected gamete frequency for haplotype gaB if the two loci are in linkage equilibrium?

Answer 40

gaB = q*s = 0.6 * 0.7 = 0.42

Question 41

Which of the following best supports the “sensory bias” hypothesis explaining how female preference for male traits can drive the evolution of exaggerated male traits?

Answer 41

Pre-existing preferences are “hard wired” due to the sensory machinery in females.

Question 42

An alternative to kin selection when explaining eusociality is the "Green Beard Hypothesis". Hamilton proposed that an allele that produces a distinctive trait (i.e., the greenbeard effect), along with altruistic behavior directed at the bearers of this trait, could drive such an altruistic allele to high frequencies in a population. What is required for this hypothesis to be plausible?

Answer 42

a perceptible trait, recipients give preferential treatment to those recognized, ability to perceive the trait by the recipient

Question 43

The idea of runaway sexual selection, also called “sexy son” hypothesis, proposes that _______________.

Answer 43

evolution of a male trait and a female preference, once initiated, becomes self-reinforcing mechanisms

Question 44

Which of the following is NOT an example of asexual reproduction?

Answer 44

In protandrous species, individuals first develop testes and later in life develop ovaries.

Question 45

Which of the following genes are NOT under strong selection in humans?p

Answer 45

processed pseudogenes

Question 46

________ is when changes in gene frequencies (evolution) occur because of chance events (sampling errors) that occur when populations are finite in size (small).

Answer 46

genetic drift

Question 47

One would expect that conflicts between parents and offspring over parental investment would be the most pronounced in ________.

Answer 47

birds

Question 48

Which hypothesis best explains mate choice in females of the moth Utetheisa ornatrix, where males provide nuptial gifts rich in pyrolizidine alkaloids?

Answer 48

direct benefits to choosy females

Question 49

What were some of the consequences of inbreeding in populations of Florida panthers?

Answer 49

failure to reproduce, low number of alleles at multiple loci, and decreasing population size

Question 50

Which of the following does NOT tend to promote speciation?

Answer 50

gene flow

Question 51

Adam Jones and colleagues (2000) studied the mating behaviors of broad-nosed pipefish (Syngnathus typhle) in a laboratory situation. For which sex is sexual selection a more potent evolutionary force?

Answer 51

females

Question 52

Anisogamy refers to _________

Answer 52

an asymmetry in the size of gametes, with one small type and one large type.

Question 53

An increase in the inbreeding coefficient, F,is likely to result in:

Answer 53

reduced likelihood of heterozygotes being present in a population

Question 54

Which of the following is NOT an acceptable definition of effective population size (Ne)?

Answer 54

Average number of individuals in an idealized population at which genetic drift does not occur.

Question 55

Which of the following processes can cause linkage disequilibrium in a population?

Answer 55

population admixture (mixing of individuals from different populations), genetic drift in finite populations, natural selection on multilocus genotypes, selective sweep

Question 56

In terms of the Hardy-Weinberg equilibrium, genetic drift results from a violation of ________.

Answer 56

the infinite population size assumption

Question 57

In protandrous species, individuals _________.

Answer 57

begin life as males and at later age switch to become females

Question 58

A principle advantage of sexual reproduction is that it ________.

Answer 58

breaks Muller's ratchet i.e. prevents the accumulation of deleterious mutations, reduces linkage disequilibrium, helps recreate genotypes that are either rare or missing in a population, but are favored by selection, regenerates genotypes in the evolutionary "arms race" between parasites and hosts

Question 59

Which of the following is a possible consequence of genetic drift?

Answer 59

In small populations, drift can quickly lead to fixation or removal of alleles. Increase in the frequency of homozygotes. Decrease in the frequency of heterozygotes. Random change in the frequency of alleles in a population.

Question 60

What would be the frequency of AABbCc individuals from a mating of two AaBbCc individuals?

Answer 60

1/16

Question 61

Which of the following traits is NOT associated with increased inbreeding in populations of Florida panthers?

Answer 61

increased fertility in females

Question 62

The neutral theory of molecular evolution, as developed by Kimura, posits that ________.

Answer 62

functionally neutral mutations that become fixed in populations occur in much larger numbers than those that become fixed by natural selection