24.2 Speciation can take place with or without geographic separation Flashcards
20) Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons?
I. The environment is unlikely to change.
II. Human evolution is complete.
III. The human races are incompletely isolated.
A) I only
B) III only
C) I and II only
D) II and III only
E) I, II, and III
B) III only
21) In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In rangelands of the western United States, pronghorns and cattle often associate with one another. If some of these fleas develop a strong preference, instead, for cattle blood and mate only with fleas that, likewise, prefer cattle blood, then over time which of these should occur, if the host mammal can be considered as the fleasʹ habitat?
1. reproductive isolation
2. sympatric speciation
3. habitat isolation
4. prezygotic barriers
A) 1 only
B) 2 and 3
C) 1,2,and3
D) 2, 3, and 4
E) 1 through 4
E) 1 through 4
22) A defining characteristic of allopatric speciation is
A) the appearance of new species in the midst of old ones.
B) asexually reproducing populations.
C) geographic isolation.
D) artificial selection.
E) large populations.
C) geographic isolation.
23) A rapid method of speciation that has been important in the history of flowering plants is
A) genetic drift.
B) a mutation in the gene controlling the timing of flowering. C) behavioral isolation.
D) polyploidy.
D) polyploidy.
24) 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?
A) They interbreed freely and produce fertile hybrid offspring.
B) They no longer attempt to interbreed.
C) They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations.
D) They remain separate in the extremes of their ranges but develop a persistent hybrid zone in the area of overlap.
E) They interbreed in the region of overlap, but produce sterile offspring.
C) They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations.
25) The difference between geographic isolation and habitat differentiation is the
A) relative locations of two populations as speciation occurs.
B) speed (tempo) at which two populations undergo speciation.
C) amount of genetic variation that occurs among two gene pools as speciation occurs.
D) identity of the phylogenetic kingdom or domain in which these phenomena occur.
E) the ploidy of the two populations as speciation occurs.
A) relative locations of two populations as speciation occurs.
26) Among known plant species, which of these have been the two most commonly occurring phenomena leading to the origin of new species?
1. allopatric speciation
2. sympatric speciation
3. sexual selection
4. polyploidy
A) 1 and 3
B) 1 and 4
C) 2and3
D) 2 and 4
D) 2 and 4
27) Beetle pollinators of a particular plant are attracted to its flowersʹ 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?
A) allopatric speciation, ecological isolation
B) sympatric speciation, habitat differentiation
C) allopatric speciation, behavioral isolation
D) sympatric speciation, sexual selection
E) sympatric speciation, allopolyploidy
B) sympatric speciation, habitat differentiation
28) The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of
A) allopatric speciation.
B) sympatric speciation.
C) autopolyploidy.
D) habitat selection.
B) sympatric speciation.
On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the islandʹs lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and found 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 speciesʹ 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.
38) If a speciation event occurred on Sao Tomé, producing D. santomea from a parent colony of D. yakuba, then which terms apply?
I. macroevolution
II. allopatric speciation
III. sympatric speciation
A) I only
B) II only
C) I & II
D) I & III
D) I & III
On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the islandʹs lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and found 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 speciesʹ 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.
39) Using only the information provided in the paragraph, which of these is the best initial hypothesis for how D. santomea descended from D. yakuba?
A) geographic isolation
B) autopolyploidy
C) habitat differentiation
D) sexual selection
E) allopolyploidy
C) habitat differentiation
