Question 1

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

Accepted Answer

A source of divergent selection

Question 2

Which scenario best illustrates a prezygotic barrier to reproduction?

Accepted Answer

Two populations mate at different times of the year

Question 3

During the Last Glacial Maximum (LGM), what was the primary effect on population genetics in the South Cascades and southern Rocky Mountains?

Accepted Answer

Genetic bottleneck due to reduced suitable habitat

Question 4

Which equation best represents the effective population size ($$N_e) $$over time as shown in the population bottleneck graph?

Accepted Answer

$$N_e$$ decreases sharply during the LGM and then increases postglacially

Question 5

Which of the following is an example of a postzygotic barrier?

Accepted Answer

Hybrid zygotes are formed but have reduced fitness

Question 6

In the context of hybrid zones, what outcome is expected if the fitness of hybrids is less than the fitness of parental forms?

Accepted Answer

Hybrid zone will be narrow and short-lived, leading to reinforcement

Question 7

Which mechanism is responsible for intrinsic postzygotic isolation?

Accepted Answer

Developmental defects due to genetic incompatibilities

Question 8

A mismatch between mitochondrial genes from the mother and nuclear genes from the father can lead to which type of hybrid incompatibility?

Accepted Answer

Cytonuclear intrinsic incompatibility

Question 9

Which real-world example illustrates extrinsic postzygotic isolation?

Accepted Answer

Hybrid sea turtles with reduced hatching success due to intermediate habitat

Question 10

If two populations of chipmunks come into secondary contact and hybrids have lower fitness, what evolutionary process is most likely to occur?

Accepted Answer

Reinforcement of reproductive isolation

Question 11

Which of the following best describes the lock-and-key mechanism in premating isolation?

Accepted Answer

Physical incompatibility prevents transfer of gametes

Question 12

In the apple and hawthorn races of Rhagoletis pomonella, what type of reproductive isolation is primarily observed?

Accepted Answer

Prezygotic isolation due to differences in emergence timing

Question 13

Which formula would you use to estimate the probability of spawning in sympatric versus allopatric populations based on the provided graph?

Accepted Answer

$$P = \frac{n_{spawn}}{n_{total}}$$

Question 14

Which scenario would most likely result in the formation of a new species in a hybrid zone?

Accepted Answer

Fitness of hybrids is greater than parental forms in a new habitat

Question 15

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

Accepted Answer

Intrinsic isolation is caused by genetic incompatibilities; extrinsic is caused by environmental factors

Question 16

Which of the following is a plausible outcome of secondary contact between two diverged populations?

Accepted Answer

Reinforcement of reproductive isolation

Question 17

Which real-world example demonstrates gametic isolation as a postmating, prezygotic barrier?

Accepted Answer

Sperm precedence preventing fertilization in fruit flies

Question 18

What is the expected effect on hatching success when hybridization occurs between sea turtles at Abrolhos Archipelago?

Accepted Answer

Hatching success decreases in hybrids compared to parental forms

Question 19

Which equation would best describe the relationship between hybrid index and individual fitness in a hybrid zone?

Accepted Answer

$$F = a 	imes H + b$$

Question 20

Which of the following is NOT a plausible mechanism linking divergent selection to reproductive isolation?

Accepted Answer

Random genetic drift in a large, stable population

lec 36s

Study Guide - Practice Questions