Chapter 22 Evolution by Natural Selection PDF

Chapter 22 Evolution by Natural Selection 1) Darwin and Wallace's theory of evolution by natural selection was revolutionary because it ________. A) was the first theory to refute the ideas of special creation B) proved that individuals acclimated to their environment over time C) dismissed the ide...

Chapter 22 Evolution by Natural Selection 1) Darwin and Wallace's theory of evolution by natural selection was revolutionary because it ________. A) was the first theory to refute the ideas of special creation B) proved that individuals acclimated to their environment over time C) dismissed the idea that species are constant and emphasized the importance of variation and change in populations D) was the first time a biologist had proposed that species changed through time Answer: C 4) Lamarck developed a hypothesis to explain the inheritance of traits that is often referred to as the "inheritance of acquired characters." This idea suggests that ________. A) as an individual develops, its genotype changes in response to challenges posed by the environment, and it passes on new phenotypic changes to offspring B) as an embryo develops, its mother's phenotype changes in response to challenges posed by the environment, and the mother passes on these phenotypic changes to offspring C) as an individual develops, its genotype changes in response to challenges posed by the environment, and it passes on these genotypic changes to offspring D) as an individual develops, its phenotype changes in response to challenges posed by the environment, and it passes on these phenotypic changes to offspring Answer: D 5) Which of the pairs of plant structures below are homologous? A) Oak tree root and leaf B) Rose bush stem and flower C) Rose bush leaf and oak tree leaf D) There are no homologous plant structures. Answer: C 6) Which of the following most strongly supports the common origin of all life on Earth? All organisms ________. A) require energy B) use essentially the same genetic code C) reproduce D) show heritable variation E) evolve Answer: B 9) About thirteen different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the thirteen species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six 1 ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction? A) They should be limited to the six islands that most recently emerged from the sea. B) Their genomes should be more similar to each other than are the genomes of the five tree finch species. C) They should share fewer anatomical homologies with each other than they share with the tree finches. D) The chances of hybridization between two ground finch species should be less than the chances of hybridization between two tree finch species. Answer: B 10) Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree? A) None of the organisms depicted by the tree ate the same foods. B) Some of the organisms depicted by the tree had lived in different habitats. C) The skeletal remains of the organisms depicted by the tree were incomplete (in other words, some bones were missing). D) Transitional fossils had not been found. E) Relationships between DNA sequences among the species did not match relationships between skeletal patterns. Answer: E 11) Fossils of Thrinaxodon, a species that lived during the Triassic period, have been found in both South Africa and Antarctica. Thrinaxodon had a reptile-like skeleton and laid eggs, but small depressions on the front of its skull suggest it had whiskers and, therefore, fur. Thrinaxodon may have been warm-blooded. The fossils of Thrinaxodon are consistent with the hypothesis that ________. A) fossils found in a given area look like the modern species in that same area B) the environment where it lived was very warm C) mammals evolved from a reptilian ancestor D) Antarctica and South Africa separated after Thrinaxodon went extinct Answer: C 12) The giant sloth described by Georges Cuvier suggests that ________. A) organisms could not have originated by special creation B) organisms could go extinct C) the great flood or some other catastrophe caused the evolution of new species D) the Earth is old enough for evolution to have occurred Answer: B 13) Many crustaceans (e.g., lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of ________. A) convergent evolution B) a homologous structure C) natural selection D) a vestigial trait 2 Answer: D 14) Which of the following, if discovered, could refute our current understanding of the pattern of evolution? A) No fossils of soft-bodied animals B) A modern bird having reptile-like scales on its legs C) Radioactive dating of rocks showing that rocks closer to the Earth's surface are younger than lower rock strata. D) Diverse fossils of mammals in Precambrian rock Answer: D 15) Similar gill pouches in embryos of a chick, human, and cat are an example of ________. A) structural homology B) developmental homology C) genetic homology D) the inheritance of acquired characters Answer: B 16) The same basic internal organs (kidneys, stomach, heart, and lungs) are found in frogs, birds, snakes, and rodents. This is primarily an example of ________. A) structural homology B) developmental homology C) genetic correlation D) inheritance of acquired characteristics Answer: A 3 17) What must be TRUE of any organ described as vestigial? A) It must be analogous to some feature in an ancestor. B) It must be homologous to some feature in an ancestor. C) It must be both homologous and analogous to some feature in an ancestor. D) It needs to be neither homologous nor analogous to some feature in an ancestor. Answer: B 18) Which piece of evidence supports the hypothesis that cetaceans (whales) evolved from terrestrial mammals as opposed to some aquatic organisms? A) A phylogeny of fossil cetaceans indicates that a gradual transition occurred between terrestrial forms and aquatic, whale-like forms. B) DNA comparisons show that whales and hippos share more genetic sequences than whales share with other organisms. C) Some modern cetaceans have a vestigial hind limb buds. D) Whales arose from a terrestrial ancestor about 50 million years ago. E) Many independent lines of evidence converge on the conclusion that whales gradually evolved from a terrestrial mammalian ancestor about 50 million years ago. Answer: E 19) A dairy farmer chooses to mate a male bull only with the female heifers that always make the greatest amount of milk, rather than heifers that produce a small amount of milk. What process is the dairy farmer employing when producing the next generation of calves? A) Natural selection B) Artificial selection C) Sexual selection D) Balancing selection Answer: B 20) Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly-adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly-adapted individuals have decreased survivorship. A) 2 → 4 → 1 → 3 B) 4 → 2 → 1 → 3 C) 4 → 1 → 2 → 3 D) 4 → 2 → 3 → 1 E) 2 → 4 → 3 → 1 Answer: A 21) Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. To test the hypothesis that having longer hair is adaptive in these males, you should ________. 4 A) test whether other traits in these males are also adaptive B) look for evidence of hair in ancestors of tamarins C) determine if hair length is heritable D) test whether males with shaved heads are still able to mate Answer: C 22) A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened? A) The herbicide company lost its triazine formula and started selling poor-quality triazine. B) Natural selection caused the pigweed to mutate, creating a new triazine-resistant species. C) Triazine-resistant pigweed has less efficient photosynthesis metabolism. D) Triazine-resistant weeds were more likely to survive and reproduce. Answer: D 23) Researchers discovered that a new strain of bacteria that causes tuberculosis (M. tuberculosis) has a point mutation in the rpoB gene that codes for part of the RNA polymerase enzyme. This mutant form of RNA polymerase does not function as well as the more common form of RNA polymerase. A commonly used antibiotic called rifampin does not affect the mutant rpoB bacteria. A researcher mixes M. tuberculosis with and without the rpoB mutation and adds the bacteria to cell cultures. Half the cell cultures contain only standard nutrients, while the other half of the cell cultures contain rifampin and the standard nutrients. After many cell generations, the researcher finds that ________. A) very few M. tuberculosis in the standard nutrient cell cultures carry the rpoB gene mutation, but almost all of the M. tuberculosis in the cell cultures with rifampin carry the rpoB mutation B) almost all M. tuberculosis in the standard nutrient cell cultures carry the rpoB gene mutation, but very few of the M. tuberculosis in the cell cultures with rifampin carry the rpoB mutation C) very few M. tuberculosis in any of the cell cultures carry the rpoB gene mutation D) almost all of the M. tuberculosis in both types of cell cultures carry the rpoB mutation E) a mix of both M. tuberculosis strains thrive in the standard cell cultures, but no living bacteria can be found in the cell cultures that contain rifampin Answer: A 24) After the drought of 1977, researchers on the island of Daphne Major hypothesized that medium ground finches that had large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. If this hypothesis is correct, what would you expect to observe if a population of these medium ground finches colonizes a nearby island where T. cistoides is the most abundant food for the next 1000 years? Assume that (1) even the survivors of the 1977 drought sometimes had difficulty cracking the tough T. cistoides fruits and would eat other seeds when offered a choice; and (2) food availability is the primary limit on finch fitness on this new island. A) Evolution of yet larger, deeper beaks over time B) Evolution of smaller, pointier beaks over time C) Random fluctuations in beak size and shape D) No change in beak size and shape 5 Answer: A 25) After the drought of 1977, researchers hypothesized that on the Galápagos island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough T. cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island? A) Evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks B) Evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks C) Increased variation in beak size and shape over time D) No change in beak size and shape over time Answer: C 26) The following question is based on information from Frank M. Frey, "Opposing Natural Selection from Herbivores and Pathogens May Maintain Floral-Color Variation in Claytonia virginica (Portulacaceae)," Evolution 58(11), 2004: 2426-37. Claytonia virginica is a woodland spring herb with flowers that vary from white to pale pink to bright pink. Slugs prefer to eat pink-flowering plants over white-flowering plants (due to chemical differences between the two), and plants experiencing severe herbivory are more likely to die. The bees that pollinate this plant also prefer pink to white flowers, so Claytonia with pink flowers have greater relative fruit set than Claytonia with white flowers. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. With no other information, if the researcher removes all slugs from the study population, what do you expect to happen to the distribution of flower colors in the population over time? A) The percentage of pink flowers should increase over time. B) The percentage of white flowers should increase over time. C) The distribution of flower colors should not change. D) The distribution of flower colors should randomly fluctuate over time. Answer: A 28) DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects. Which of these would have prevented this evolution of DDT resistance in insect pests? A) Larger doses of DDT should have been applied from the air, into water, and within the soil. B) All habitats should have received applications of DDT at about the same time. C) The frequency of DDT application should have been higher. D) None of the insect pests would have genetic variations that resulted in DDT resistance. E) DDT application should have been continual. Answer: D 29) If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would happen in environments that lack antibiotics? 6 A) These genes would be maintained in case the antibiotics appear. B) These bacteria would be outcompeted and replaced by bacteria that have lost these genes. C) These bacteria would try to make the cost worthwhile by locating and migrating to microenvironments where traces of antibiotics are present. D) The number of genes conveying antibiotic resistance would increase in these bacteria. Answer: B 30) Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is TRUE? A) Each bird evolved a deeper, stronger beak as the drought persisted. B) Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted. C) Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation. D) The frequency of the strong-beak alleles increased in each bird as the drought persisted. Answer: B 31) There is a population of beetles that typically have black wings. A scientist studying these beetles knows that their eggs hatch in early spring, the young insects grow through the late spring and summer, they lay eggs in the early fall, and they die in the early winter. Recently some beetles have been born with white wings. Early in life, the black- and white-winged beetles seem to be very similar in number of mating events, eggs laid, and survival rates, but shortly after laying their eggs, the white beetles die, and there are only black-winged beetles during the late fall. Which of the following is a TRUE statement about the beetles? A) White- and black-winged beetles have equal fitness. B) Black-winged beetles have a higher fitness than white-winged beetles. C) The number of baby white-winged beetles will decrease in frequency over time. D) White wings are an adaptation. Answer: A 32) Biological fitness is best defined as ________. A) a heritable trait that increases the match of an individual to its environment B) variability in the population for a trait that increases survival C) the ability of an individual to produce offspring that survive and reproduce, relative to other individuals in the population D) competition among individuals for resources that allow them to have more offspring E) similar reproductive success among individuals in a population Answer: C 33) If you say that a ground squirrel has greater evolutionary fitness than another ground squirrel in the same population, you mean that the animal ________. A) has a longer life B) is able to mate more frequently C) is able to dominate other squirrels to gain access to food D) has more offspring that survive and reproduce themselves E) All of the above statements are correct. Answer: D 7 34) Vestigial traits and neutral changes in DNA sequences are good examples of ________. A) adaptation B) acclimation C) convergent traits D) nonadaptive traits E) none of the above Answer: D 35) Which of the following is a fitness trade-off (compromise)? A) In some hornbill species, the male helps seal the female in a tree with her nest until the young are ready to fledge. B) Hummingbirds are the best pollinators of certain flowers, but bees are the best pollinators for orchids. C) The strong, thick beak of a woodpecker helps it find insects in trees. D) Turtle shells provide protection but are heavy and burdensome when moving. Answer: D 36) Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses? A) Natural selection cannot account for losses but accounts only for new structures and functions. B) Natural selection accounts for these losses by the principle of use and disuse. C) Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits. D) The ancestors of these organisms experienced harmful mutations that forced them to lose these structures. Answer: C 37) A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do NOT seem to be optimally arranged because ________. A) natural selection has not had sufficient time to create the optimal design in each case but will do so given enough time B) in many cases, phenotype is determined by genotype and the environment C) though we may not consider the fit between the current skeletal arrangements and their functions excellent, we should not doubt that natural selection ultimately produces the best design D) natural selection is generally limited to modifying structures that were present in previous generations and/or in previous species Answer: D 38) Use the following information to answer the question below. In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20 percent of the β hemoglobin alleles in the human gene pool. 8 The sickle-cell allele is pleiotropic (i.e., it affects more than one phenotypic trait). Specifically, this allele affects oxygen delivery to tissues and affects one's susceptibility to malaria. Heterozygous individuals who have one normal and one sickle-cell allele have a phenotype that has both costs and benefits. The cost: Under conditions of low atmospheric oxygen availability, individuals heterozygous for this allele can experience life-threatening sickle-cell "crises." The benefit: Such individuals are less susceptible to malaria. Thus, pleiotropic genes/alleles reveal that ________. A) new advantageous alleles do not arise on demand B) evolution is limited by historical constraints C) adaptations are often compromises D) chance events can affect the evolutionary history of populations Answer: C 54) Which drawing of a population of bacteria does the best job of illustrating Darwin's first postulate, that there is variation among individuals in a population? (The color red represents the ability of the bacteria to digest the sugar lactose.) A) B) C) D) Answer: D LO: 22.3; EO: 22.3.2 9 55) Which drawing of a population of bacteria does the best job of illustrating Darwin's fourth postulate, that reproduction and/or survival are nonrandom? (The color red represents the ability of the bacteria to digest the sugar lactose.) A) B) C) D) Answer: B LO: 22.3; EO: 22.3.2 10 56) Chris has drawn a model of grass plants to represent which of Darwin's postulates? Select all that apply. A) Variation exists among individuals in a population. B) Some variation is heritable. C) Survival and reproductive success is variable. D) Survival and reproductive success is nonrandom. Answer: A, B, C, D 11 12