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

According to Ernst Mayr, what is the primary influence of geography on speciation?

Accepted Answer

Geography influences reproductive isolation through dispersal limitation and niche occupancy

Question 3

Which equation best represents the calculation of genetic differentiation between populations using $$F_{ST}$$ values?

Accepted Answer

$$F_{ST} = \frac{H_T - H_S}{H_T}$$

Question 4

In the context of parapatric speciation, which scenario is most likely to result in new species formation?

Accepted Answer

Populations occupy adjacent regions with weak gene flow and divergent selection for different gene combinations

Question 5

Which of the following is a real-world example of sympatric speciation?

Accepted Answer

Formation of new species of Rhagoletis flies on apple and hawthorn trees

Question 6

What is the primary mechanism linking divergence selection to reproductive isolation in ecological speciation?

Accepted Answer

Ecologically based divergent selection between environments

Question 7

Which of the following best explains why Rhagoletis pomonella flies on apple and hawthorn trees exhibit reproductive isolation?

Accepted Answer

Differences in pupal emergence times align with fruit maturation, reducing hybrid fitness

Question 8

Which of the following is NOT a premating barrier to reproduction?

Accepted Answer

Hybrid sterility

Question 9

A population of insects experiences strong selection for adaptation to different soil types along an environmental gradient. Gene flow is reduced but not eliminated. Which speciation model does this scenario best illustrate?

Accepted Answer

Parapatric speciation

Question 10

In the Bush (1969) model for sympatric speciation in Rhagoletis, which factor is assumed to be under genetic control?

Accepted Answer

Diapause and emergence times

Question 11

Which formula would you use to calculate the mean ovipositor length from a sample of $$n$$ flies?

Accepted Answer

$$\bar{x} = \frac{\sum_{i=1}^{n} x_i}{n}$$

Question 12

Which of the following is a requirement for ecological speciation according to Nosil (2012)?

Accepted Answer

A source of divergence selection

Question 13

If $$F_{ST}$$ values are significantly higher in hawthorn populations than apple populations, what does this indicate?

Accepted Answer

Hawthorn populations have greater genetic differentiation

Question 14

Which scenario best illustrates temporal isolation as a premating barrier?

Accepted Answer

Two populations breed at different times of the year

Question 15

Which of the following is a plausible outcome if Rhagoletis flies shift host preference from hawthorn to apple?

Accepted Answer

Genetic differentiation due to host-specific adaptation and reproductive isolation

Question 16

Which equation would you use to calculate the variance in ovipositor length among $$n$$ flies?

Accepted Answer

$$s^2$$ = \frac{\sum_{i=1}^{n} (x_i - \bar{x}$$)^2$$}{n-1}$$

Question 17

Which of the following best describes the relationship between host plant and mate selection in Rhagoletis flies?

Accepted Answer

Host plant selection and mate selection are positively correlated

Question 18

Which of the following is a plausible explanation for the lack of significant difference in ovipositor length between apple and hawthorn races of Rhagoletis pomonella?

Accepted Answer

Ovipositor length is not under strong divergent selection

Question 19

Which of the following best describes the effect of emergence time on genetic differentiation in Rhagoletis flies?

Accepted Answer

Genetic differentiation increases as emergence times diverge between host races

lec 34

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