The peppered moth provides a well-known example of natural selection. The light-colored form of
the moth was predominant in England before the Industrial Revolution. In the mid-nineteenth
century, a dark-colored form appeared. The difference is produced by a dominant allele of one
gene. By about 1900, approximately 90% of the moths around industrial areas were dark colored,
whereas light-colored moths were still abundant elsewhere. Apparently, birds could readily find
the light moths against the soot-darkened background in industrial areas and, therefore, were
eating more light moths. Recently, use of cleaner fuels has greatly reduced soot in the landscape,
and the dark-colored moths have been disappearing. Should the two forms of moths be considered
A) Yes, because natural selection has affected the frequency of the two different forms.
B) Yes, because they are reproductively isolated based on habitat.
C) Yes, because they have completely different coloration and natural selection has affected the
frequency of the two different forms.
D) Yes, because they have completely different coloration.
Rank the following in order from most general to most specific:
1. gametic isolation
2. reproductive isolating mechanism
3. sperm-egg incompatibility in sea urchins
4. prezygotic isolating mechanism
A) 4, 1, 2, 3 B) 2, 3, 1, 4 C) 2, 1, 4, 3 D) 4, 2, 1, 3 E) 2, 4, 1, 3
Which of the following describes the most likely order of events in speciation?
A) genetic isolation, divergence, genetic drift
B) divergence, genetic isolation, genetic drift
C) divergence, genetic drift, genetic isolation
D) genetic drift, genetic isolation, divergence
E) genetic isolation, genetic drift, divergence
You want to study divergence of populations, and you need to maximize the rate of divergence in
order to see results within the period of your grant funding. You will form a new population by
taking some individuals from a source population and isolating them so the two populations
cannot interbreed. What combination of characteristics would maximize your chance of seeing
divergence in this study?
1. Choose a random sample of individuals to form the new population.
2. Choose individuals from one extreme to form the new population.
3. Choose a species to study that produces many offspring.
4. Choose a species to study that produces a few, large offspring.
5. Place the new population in the same type of environment as the source population.
6. Place the new population in a novel environment compared to that of the source
A) 1, 3, and 6
B) 1, 4, and 6
C) 2, 3, and 5
D) 2, 3, and 6
E) 2, 4, and 6