Origin of Species Practice Questions
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Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books show them as eastern and western forms of a single species, the yellow-rumped warbler. Apparently, the myrtle warbler and Audubon's warbler _____. |
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| live in the same areas | ||
| successfully interbreed and produce fertile offspring | ||
| are almost identical in appearance | ||
| are merging to form a single species | ||
| live in different places | ||
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According to the "biological species" concept, what is a species? |
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| a population that interbreeds and produces fertile offspring | ||
| a population that is physically able to mate even if there are no offspring or the offspring is infertile | ||
| a population with a distinct fossil record | ||
| a clone of genetically identical organisms | ||
| a cluster of organisms that have a lineage of descent | ||
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Imagine a scenario in which part of a population of South American finches is blown by a storm onto an island far offshore and manages to survive and reproduce there for a period of 10,000 years. After that period, a climate change results in lower sea levels and the reconnection of the island with the mainland. Members of the formerly isolated island finch population can now interact freely with members of the original mainland population. Which of the following observations would, by itself, lead you to conclude unequivocally that the island finch population had evolved into a distinct species? |
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| The island birds all have red feathers, but the mainland birds have only green feathers. | ||
| Individuals from the different populations sometimes mate with each other, but all of the resulting eggs are sterile. | ||
| Individuals from the different populations seem to mate freely with each other, and the resulting offspring mate freely with either island birds or mainland birds. | ||
| Individuals from the different populations feed on the same kinds of seeds in the same habitats and frequently direct courtship behavior toward members of the other population. | ||
| Hybrid offspring of matings between individuals from the two populations do not look like either parent. | ||
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Which one of the following conditions is necessary for speciation to occur? |
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| reproductive isolation | ||
| sympatric allopatry | ||
| adaptive radiation | ||
| mass extinction | ||
| interbreeding among neighboring populations | ||
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For which one of the following groups would the biological definition of species be LEAST useful? |
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| elephants | ||
| pine trees | ||
| mosses | ||
| mushrooms | ||
| asexually reproducing organisms | ||
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According to the "biological species" concept (that is, our definition of "species"), members of different species _____. |
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| look different from each other | ||
| live in different geographic areas | ||
| do not mate successfully under natural conditions | ||
| speak different languages | ||
| belong to different political parties | ||
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Each species has a closed gene pool because _____. |
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| no gene lifeguard is on duty | ||
| each parent contributes only half of each offspring's genes | ||
| each species is reproductively isolated | ||
| different species can interbreed freely | ||
| lions and tigers can hybridize in captivity | ||
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The biological species concept CANNOT be applied to organisms that _____. |
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| have similar phenotypes | ||
| breed in different habitats | ||
| reproduce only asexually | ||
| are sympatric | ||
| all of the above | ||
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Imagine that part of a population of flies is blown from the California coast to an offshore island. The island flies have no contact with the mainland flies for 10,000 years. Then an earthquake rearranges the landscape and the island is rejoined to the mainland. The former island flies can now mingle freely with the mainland flies. If attempts at mating between flies from the two groups are successful and the resulting baby flies grow up strong and healthy and have offspring of their own, you could conclude that _________. |
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| over the past 10,000 years, a single species had split into two species | ||
| over the past 10,000 years, effective isolating mechanisms had evolved | ||
| over the past 10,000 years, no speciation occurred in these flies | ||
| there is insufficient information available to determine how many species of flies are now present | ||
| flies will mate no matter what | ||
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Which of the following is an example of a postzygotic reproductive barrier? |
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| One species of frog mates in April; another mates in May. | ||
| Two fruit flies of different species produce sterile offspring. | ||
| The sperm of a marine worm penetrate eggs of the same species only. | ||
| One species of flower grows in forested areas, another in meadows. | ||
| Two pheasant species perform different courtship dances. | ||
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Which of the following is an example of a postzygotic reproductive barrier? |
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| One Ceanothus shrub lives on acid soil, another on basic soil. | ||
| Mallard and pintail ducks mate at different times of the year. | ||
| Two species of leopard frogs have different mating calls. | ||
| The hybrid offspring of two species of jimsonweeds always die before reproducing. | ||
| Pollen of one kind of tobacco cannot fertilize another kind. | ||
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Which of the following is NOT an example of a postzygotic barrier? |
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| A hybrid fails to reach sexual maturity. | ||
| A hybrid fails to develop. | ||
| A hybrid fails to produce functional gametes. | ||
| The offspring of hybrids are infertile. | ||
| The two populations live in the same general area but not the same type of environment. | ||
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At which point in the adaptation of a population is it clear that speciation has occurred? |
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| gene pool changes adapt a population to a local environment | ||
| gene pool changes establish reproductive barriers between two populations | ||
| an allopatric separation occurs | ||
| hybrid inviability occurs | ||
| all of the above | ||
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Three or four of the following conditions may lead to reproductive isolation between two species of similar physical appearance. Which one, if any, will NOT lead to reproductive isolation? If all the conditions will lead to reproductive isolation, choose answer (5). |
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| Their geographic ranges do not overlap. | ||
| The mating behaviors of the two species are very different. | ||
| The gametes of the two species do not form a viable zygote when combined. | ||
| They have different habitat preferences. | ||
| All of the above conditions will lead to reproductive isolation. | ||
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Biologists have found more than 500 species of fruit flies on the various Hawaiian Islands, all apparently descended from a single ancestor species. This example illustrates _____. |
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| polyploidy | ||
| temporal isolation | ||
| adaptive radiation | ||
| hybrid breakdown | ||
| meiotic failure | ||
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Speciation is likely to occur in a population that has become allopatric if _____. |
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| both gene pools are large and exhibit sufficient diversity of alleles | ||
| it is a species of plant only; allopatric speciation does not occur in animals | ||
| at least one of the gene pools is small | ||
| nonrandom mating does not occur | ||
| some individuals live in fresh water while others remain on land | ||
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Which of the following organisms is most likely to be subject to allopatric speciation? |
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| whales of the same species on each side of the ocean | ||
| pine trees in Alaska and pine trees in New Brunswick | ||
| mountain lions in the canyons of Wyoming and in the canyons of Utah | ||
| fruit flies on bananas and fruit flies on oranges | ||
| bacteria in a hospital and bacteria in a nursery | ||
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Which of the following is NOT an example of adaptive radiation? |
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| bony fish fitting into all areas of the ocean and fresh water | ||
| insects adapting to every land environment | ||
| speciation of finches into each Galápagos island environment | ||
| the few species of roundworms existing virtually everywhere in the world | ||
| placental mammals replacing reptiles and earlier mammals in their niches | ||
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Which of the following is NOT a probable event in the evolution of a polyploid species? |
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| hybridization of the two parent species | ||
| failure of meiosis in the resultant hybrid | ||
| sterility of triploid individuals | ||
| gametes forming by mitosis | ||
| mutation of cell cycle genes | ||
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If a new species of plant is to be produced by means of allopolyploidy from two parental species that are 2n = 4 and 2n = 8, how many chromosomes would you expect in the somatic cells of the new species? |
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| 6 | ||
| 12 | ||
| 24 | ||
| 48 | ||
| none of the above | ||
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A new species can arise in a single generation _____. |
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| through geographic isolation | ||
| in a very large population spread over a large area | ||
| if a change in chromosome number creates a reproductive barrier | ||
| if allopatric speciation occurs | ||
| according to the gradualist model of speciation | ||
Answers: 1-B, 2-A, 3-B, 4-A, 5-E, 6-C, 7-C, 8-C, 9-C, 10-B, 11-D, 12-E, 13-E, 14-E, 15-C, 16-C, 17-B, 18-D, 19-E, 20-B, 21-C