Q: Which equation best represents the additive effects of genes inherited from each parent species on hybrid growth, as shown in laboratory crosses?

$$\text{Mean growth} = \frac{G_{benthic} + G_{limnetic}}{2}$$

Question 1

Which of the following best describes the three-step process of speciation?

Accepted Answer

Populations are isolated, phenotypic trait divergence, reproductive isolation

Question 2

Ecological speciation requires which three components to occur?

Accepted Answer

A source of divergence selection, a form of reproductive isolation, and a way to link divergence selection to reproductive isolation

Question 3

In the Bateson-Dobzhansky-Muller (BDM) model, what is the primary cause of extrinsic postzygotic isolation?

Accepted Answer

Ecological factors leading to poor performance by hybrids in intermediate niches

Question 4

Which equation best represents the additive effects of genes inherited from each parent species on hybrid growth, as shown in laboratory crosses?

Accepted Answer

$$	ext{Mean growth} = \frac{G_{benthic} + G_{limnetic}}{2}$$

Question 5

In stickleback fish, what is the relationship between growth rate and ecological niche?

Accepted Answer

Growth rate is highest in limnetic and benthic fish when they are in their respective ecological niches

Question 6

Which of the following is an example of premating reproductive isolation?

Accepted Answer

Male preference for mates based on size of female

Question 7

What is the main difference between intrinsic and extrinsic postzygotic isolation?

Accepted Answer

Intrinsic isolation is caused by developmental defects independent of environment, while extrinsic isolation is caused by ecological factors

Question 8

According to Wu's genic view of speciation, what is the unit of adaptation?

Accepted Answer

A gene or set of genes that are polygenic or in linkage disequilibrium

Question 9

Which scenario best illustrates reinforcement in sympatric populations?

Accepted Answer

Females preferentially mate with their own species to produce more fit offspring

Question 10

If two populations of sticklebacks are isolated and experience different environments, which evolutionary forces are most likely to drive their genetic differentiation?

Accepted Answer

Genetic drift and natural selection

Question 11

In the context of ecological speciation, what does the term 'divergent selection' refer to?

Accepted Answer

Selection that acts differently in different environments, leading to divergence between populations

Question 12

Which of the following best explains why hybrid sticklebacks often have reduced fitness?

Accepted Answer

Hybrids occupy an intermediate niche where their growth rate is lower than either parental form

Question 13

Which formula would you use to calculate the proportion of the genome from population A that would perform worse in population B, according to the BDM model?

Accepted Answer

$$P = \frac{D_{A,B}}{G}$$

Question 14

Which of the following is a real-world example of ecological speciation as described in the study materials?

Accepted Answer

Benthic and limnetic sticklebacks diverging in British Columbia lakes

Question 15

What is the significance of size-adjusted gill raker length in stickleback speciation studies?

Accepted Answer

It is a phenotypic trait that diverges between benthic and limnetic forms, indicating adaptation to different niches

Question 16

Which of the following best describes the role of regulatory genes in stickleback adaptation?

Accepted Answer

Regulatory genes play a significant role in adaptive evolution, often more than coding genes

Question 17

In a sympatric population of sticklebacks, what would you expect to observe regarding male mate preference?

Accepted Answer

Males preferentially mate with females of their own ecotype, often based on size

Question 18

Which of the following statements about the Biological Species Concept (BSC) and Wu's genic view is correct?

Accepted Answer

BSC emphasizes reproductive isolation at the level of the whole genome, while Wu's genic view emphasizes adaptation at the gene level

Question 19

Which scenario would most likely lead to reinforcement in a population?

Accepted Answer

Females that mate with their own species produce more fit offspring than those that mate at random

Lec 35

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