9
Refer to the scenario below, and then answer the following question(s).
Species of fruit fly larvae in the genus Rhagoletis each feed on a particular kind of fruit.
Rhagoletis pomonella feeds on the small red fruit of the hawthorn tree. In 1865, farmers in the
Hudson River valley found that R. pomonella flies had begun attacking their apples and then
spread to apple orchards in adjacent areas of Massachusetts and Connecticut. These now separate
varieties of flies, the apple and haw flies, usually don’t interbreed with each other because their
periods of mating coincide with the different ripening times of apples and hawthorn fruit. Each
variety is becoming specialized to feed and reproduce in its own particular microhabitat and may
be transitioning to separate species.
32) If the apple and haw flies become distinct enough to be separate species, their evolution is an
example of:
A) gametic isolation.
B) behavioral isolation.
C) sympatric speciation.
D) allopatric speciation.
33) If the apple and haw flies no longer interbreed due to the different ripening times of apples
and hawthorns, this would be an example of what kind of reproductive isolating mechanism?
A) ecological isolation
B) temporal isolation
C) behavioral isolation
D) mechanical isolation
E) gametic isolation
34) When the London underground (subway) system was built in the nineteenth century,
mosquitoes moved into the tunnels and became adapted to biting the customers and small
animals that inhabit the subway system. Like people, mosquitoes can freely enter and leave
through the tunnel entrances. Recently, DNA analysis and attempts to cross-breed above-ground
mosquitoes with underground mosquitoes indicate that there are now two different species. The
underground insects are visibly larger. Which term best describes what has happened?
A) sympatric speciation
B) behavioral incompatibility
C) temporal isolation
D) population bottleneck
35) Thinking of the examples in your book of adaptive radiation, in which of the following
environments might you be most likely to find adaptive radiation?
A) among houseflies living in a garbage dump