On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences.
1. improved gene flow
2. bottleneck effect
3. sexual selection
4. founder effect
5. natural selection
A) 1 and 3
B) 2 and 3
C) 2 and 4
D) 3 and 4
E) 3 and 5
Answer: E
A) behavioral isolation
B) habitat isolation
C) temporal isolation
D) mechanical isolation
E) gametic isolation
Answer: A
A) Build a canal linking the two ponds that permits free movement of mosquitofish, but not of predators.
B) Transfer only female mosquitofish from a predator-rich pond to a predator-poor pond.
C) Perform a reciprocal transfer of females between predator-rich and predator-poor ponds.
D) Remove predators from a predator-rich pond and transfer them to a predator-poor pond.
Answer: A
A) stabilizing selection; directional selection
B) stabilizing selection; stabilizing selection
C) less-intense directional selection; more-intense directional selection
D) less-intense disruptive selection; more-intense disruptive selection
Answer: C
1. directional selection for increased speed
2. stabilizing selection for speed that matches that of the mosquitofish
3. change in hunting behavior that replaces reliance on visual cues with reliance on tactile cues, which can be used to hunt at night
4. change in hunting behavior that eliminates speed in favor of better camouflage, which permits an ambush strategy
A) 1 only
B) 2 only
C) either 1 or 3
D) either 2 or 3
E) 1, 3, or 4
Answer: E
Which two of the following have operated to increase divergence between mosquitofish populations on Andros?
1. improved gene flow
2. bottleneck effect
3. sexual selection
4. founder effect
5. natural selection
A) 1 and 3
B) 2 and 3
C) 2 and 4
D) 3 and 4
E) 3 and 5
Answer: E
Which type of reproductive isolation operates to keep the mosquito fish isolated, even when fish from different ponds are reunited in the same body of water?
A) behavioral isolation
B) habitat isolation
C) temporal isolation
D) mechanical isolation
E) gametic isolation
Answer: A
What is the best way to promote fusion between two related populations of mosquitofish, one of which lives in a predator-rich pond, and the other of which lives in a predator-poor pond?
B) Transfer only female mosquitofish from a predator-rich pond to a predator-poor pond.
C) Perform a reciprocal transfer of females between predator-rich and predator-poor ponds.
D) Remove predators from a predator-rich pond and transfer them to a predator-poor pond.
Answer: A
If one builds a canal linking a predator-rich pond to a predator-poor pond, then what type(s) of selection should subsequently be most expected among the mosquitofish in the original predator-rich pond, and what type(s) should be most expected among the mosquitofish in the formerly predator-poor pond?
B) stabilizing selection; stabilizing selection
C) less-intense directional selection; more-intense directional selection
D) less-intense disruptive selection; more-intense disruptive selection
Answer: C
The predatory fish rely on visual cues and speed to capture mosquitofish. Mosquitofish rely on speed and visual cues to avoid the predatory fish. Which adaptation(s) might help the predators survive in ponds that are home to faster mosquitofish?
1. directional selection for increased speed
2. stabilizing selection for speed that matches that of the mosquitofish
3. change in hunting behavior that replaces reliance on visual cues with reliance on tactile cues, which can be used to hunt at night
4. change in hunting behavior that eliminates speed in favor of better camouflage, which permits an ambush strategy
A) 1 only
B) 2 only
C) either 1 or 3
D) either 2 or 3
E) 1, 3, or 4
Answer: E
The Origin of Species
- Suppose that a group of male pied flycatchers migrated from a region where there were no collared flycatchers to a region where both species were present. Assuming events like this are very rare, which of the following scenarios is least likely?
- Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The diploid number for species C would probably be
- Which of the following factors would not contribute to allopatric speciation?
- Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification?
- According to the punctuated equilibria model,
- Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?
- The largest unit within which gene flow can readily occur is a
- On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago.
- In order for speciation to occur, what must be true?
- Which of the following statements about speciation is correct?
- Speciation Speciation A) occurs at such a slow pace that no one has ever observed the emergence of new species. B) occurs only by the accumulation of genetic change over vast expanses of time. C) must begin with the geographic isolation of a small, frontier population. D) and microevolution are synonymous. E) can involve changes to a single gene.
- According to the concept of punctuated equilibrium,
- According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that
- A narrow hybrid zone separates the toad species Bombina bombina and Bombina variegata. What is true of those alleles that are unique to the parental species?
- The most likely explanation for the recent decline in cichlid species diversity in Lake Victoria is
- The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is
- Which of these should decline in hybrid zones where reinforcement is occurring?
- A hybrid zone is properly defined as
- The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and
- The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of
- Beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it?
- Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species?
- The difference between geographic isolation and habitat differentiation is the
- Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet?