Question 1

Which of the following best describes ecological speciation?

Accepted Answer

The process by which barriers to gene flow evolve between populations as a result of ecologically based divergent selection between environments.

Question 2

Heliconius butterflies use wing colors and patterns for which two primary functions?

Accepted Answer

Aposematic warnings and mate recognition cues.

Question 3

What prediction is made about reproductive isolation (RI) in Heliconius butterflies if wing colors/patterns serve as mate recognition cues?

Accepted Answer

Males of species that are sympatric with sister taxa should avoid mating with these congeners.

Question 4

Which of the following is a correct definition of a supergene?

Accepted Answer

A group of loci in linkage disequilibrium that provide integrated control of adaptive phenotypes.

Question 5

If two Heliconius species come into secondary contact and hybrids have reduced fitness, what evolutionary process is most likely to occur?

Accepted Answer

Reinforcement, which increases reproductive isolation.

Question 6

Which equation best represents the Hardy-Weinberg equilibrium for allele frequencies?

Accepted Answer

$$p^2 + 2pq$$ + $$q^2 = 1$

Question 7

A Heliconius population is split by a river, resulting in two groups with different wing patterns. Over time, these groups develop reproductive isolation. Which mechanism is most likely responsible?

Accepted Answer

Ecological speciation due to divergent selection.

Question 8

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

Accepted Answer

Divergence in phenotypic traits that prevent fertilization from occurring.

Question 9

In Heliconius butterflies, what is the consequence of hybridization when hybrids are fertile?

Accepted Answer

Gene flow reduces any genetic differentiation that has occurred while the populations were isolated.

Question 10

Which scientist is known for his work on the Amazon and contributed to the understanding of speciation?

Accepted Answer

Henry Walter Bates

Question 11

If a supergene controls wing pattern in Heliconius butterflies, what is the evolutionary advantage?

Accepted Answer

Integrated control of adaptive phenotypes increases fitness in specific environments.

Question 12

Which of the following best explains why males from allopatric populations might not avoid mating with sister taxa?

Accepted Answer

They have not experienced divergent selection for mate recognition cues.

Question 13

What is the primary function of aposematic coloration in Heliconius butterflies?

Accepted Answer

To warn predators of toxicity.

Question 14

Which outcome is expected if reinforcement occurs after secondary contact between diverged populations?

Accepted Answer

Selection will reduce the fitness of hybrids and lead to reproductive isolation.

Question 15

Which of the following is NOT a possible outcome when two diverged species come into secondary contact?

Accepted Answer

Genetic drift causing immediate extinction

Question 16

If $$p is $$the frequency of allele A and $$q is $$the frequency of allele a in a population, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq$$

Question 17

Which scenario best illustrates postzygotic reproductive isolation?

Accepted Answer

Hybrid offspring are infertile.

Question 18

Why are supergenes often found in linkage disequilibrium?

Accepted Answer

Because recombination between loci would disrupt the integrated control of adaptive phenotypes.

Question 19

Which of the following best describes the role of mate recognition cues in speciation?

Accepted Answer

They prevent gene flow between populations by enabling individuals to identify conspecific mates.

Question 20

What is the significance of the study 'Reproductive isolation caused by colour pattern mimicry' in Heliconius butterflies?

Accepted Answer

It demonstrates that color pattern mimicry can act as a prezygotic barrier to gene flow.

Lec 37

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