How Populations Evolve Part 1

How Populations Evolve Multiple-Choice Questions 1) Blue-footed boobies have webbed feet and are comically clumsy when they walk on land. Evolutionary scientists view these feet as A) an example of a trait that is poorly adapted. B) the outcome of a trade-off: Webbed feet perform poorly on land, but are very helpful in diving for food. C) an example of a trait that has not evolved. D) a curiosity that has little to teach us regarding evolution. Answer: B 2) The core theme of biology, which explains both the unity and diversity of life, is A) genetics. B) ecology. C) evolution. D) metabolism. Answer: C 3) Aristotle believed that A) species evolve through natural selection and other mechanisms. B) an individual's use of a body part causes it to further evolve. C) species are fixed (permanent) and perfect. D) the best evidence for change within species is seen in fossils. Answer: C 4) Darwin found that many of the species on the Galápagos islands A) resembled species on the nearest mainland. B) resembled species in Europe. C) resembled species from Australia. D) were identical to South American species. Answer: A 5) Lyell's book Principles of Geology, which Darwin read on board the H.M.S. Beagle, argued in favor of which of the following concepts? A) Earth's surface is shaped mainly by occasional catastrophic events. B) Meteorite impacts may have been a major cause of periodic mass extinctions. C) Earth's surface is shaped by natural forces that act gradually and are still acting. D) The processes that shape Earth today are very different from those that were at work in the past. Answer: C 6) Who developed a theory of evolution almost identical to Darwin's? A) Lyell B) Wallace C) Aristotle D) Lamarck Answer: B 7) Which of the following statements would Darwin have disagreed with? A) Species change over time. B) Living species have arisen from earlier life-forms. C) Descent with modification occurs through inheritance of acquired characteristics. D) Descent with modification occurs by natural selection. Answer: C 8) During the 1950s, a scientist named Lysenko tried to solve the food shortages in the Soviet Union by breeding wheat that could grow in Siberia. He theorized that if individual wheat plants were exposed to cold, they would develop additional cold tolerance and pass it to their offspring. Based on the ideas of artificial and natural selection, do you think this project worked as planned? A) Yes; the wheat probably evolved better cold tolerance over time through inheritance of acquired characteristics. B) No, because Lysenko took his wheat seeds straight to Siberia instead of exposing them incrementally to cold. C) No, because there was no process of selection based on inherited traits. Lysenko assumed that exposure could induce a plant to develop additional cold tolerance and that this tolerance would be passed to the plant's offspring. D) Yes, because this is generally the method used by plant breeders to develop new crops. Answer: C 9) Broccoli, cabbages, and Brussels sprouts all descend from the same wild mustard and can still interbreed. These varieties were produced by A) artificial selection. B) natural selection. C) genetic drift. D) inheritance of acquired characteristics. Answer: A 10) Which of the following best expresses the concept of natural selection? A) differential reproductive success based on inherited characteristics B) inheritance of acquired characteristics C) change in response to need D) a process of constant improvement, leading eventually to perfection Answer: A 11) Which of the following assumptions or observations is not part of Darwin's idea of natural selection? A) Whether an organism survives and reproduces is almost entirely a matter of random chance. B) Heritable traits that promote successful reproduction should gradually become more common in a population. C) Populations produce more offspring than their environment can support. D) Organisms compete for limited resources. Answer: A 12) Which of the following thinkers argued that much of human suffering was the result of human populations increasing faster than food supply, an argument that later influenced Charles Darwin's ideas of natural selection? A) Charles Lyell B) Thomas Malthus C) Jean-Baptiste Lamarck D) Gregor Mendel Answer: B 13) A dog breeder wishes to develop a breed that does not bark. She starts with a diverse mixture of dogs. Generation after generation, she allows only the quietest dogs to breed. After 30 years of work she has a new breed of dog with interesting traits, but on average, the dogs still bark at about the same rate as other dog breeds. Which of the following would be a logical explanation for her failure? A) There is no variation for the trait (barking). B) The tendency to bark is not a heritable trait. C) The selection was artificial, not natural, so it did not produce evolutionary change. D) There was no selection (differential reproductive success) related to barking behavior. Answer: B 14) Which of the following statements regarding natural selection is false? A) Natural selection depends on the local environment at the current time. B) Natural selection starts with the creation of new alleles that are directed toward improving an organism's fitness. C) Natural selection and evolutionary change can occur in a short period of time (a few generations). D) Natural selection can be observed working in organisms alive today. Answer: B 15) Which of the following would prevent an organism from becoming part of the fossil record when it dies? A) It is fully decomposed by bacteria and fungi. B) It is buried in fine sediments at the bottom of a lake. C) It gets trapped in sap. D) It is frozen in ice. Answer: A 16) Which of the following statements regarding the currently available fossil record is false? A) The currently available fossil record shows that the earliest fossils of life are about 3.5 billion years old. B) The currently available fossil record shows that younger strata were laid down on top of older strata. C) The currently available fossil record documents gradual evolutionary changes that link one group of organisms to another. D) The currently available fossil record shows that the first life-forms were eukaryotes. Answer: D 17) Which of the following disciplines has found evidence for evolution based on the native distributions (locations) of living species? A) molecular biology B) comparative anatomy C) geographic distribution D) paleontology Answer: C 18) Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of A) geographic similarity. B) homology. C) adaptation by natural selection. D) coincidental similarity. Answer: B 19) Which of the following represents a pair of homologous structures? A) the wing of a bat and the scales of a fish B) the wing of a bat and the flipper of a whale C) the antennae of an insect and the eyes of a bird D) the wing of a bat and the wing of a butterfly Answer: B 20) What evidence is used to determine the branching sequence of an evolutionary tree? A) experiments in artificial selection B) anatomical or molecular homologous structures C) the genetic code D) an overall assessment of general similarities between organisms Answer: B 21) Darwin was the first person to draw an evolutionary tree, a diagram that represents A) records of breeding in domesticated animals. B) records of lineages in humans (also known as a family tree). C) evidence-based hypotheses regarding our understanding of patterns of evolutionary descent. D) groupings of organisms based on overall similarity. Answer: C 22) A population is A) a group of individuals of the same species that live in the same area and interbreed. B) all individuals of a species, regardless of location or time period in which they live. C) a group of individuals of different species living in the same place at the same time. D) a group of individuals of a species plus all of the other species with which they interact. Answer: A 23) Microevolution, or evolution at its smallest scale, occurs when A) an individual's traits change in response to environmental factors. B) a community of organisms changes due to the extinction of several dominant species. C) a new species arises from an existing species. D) a population's allele frequencies change over a span of generations. Answer: D 24) The ultimate source of all new alleles is A) mutation. B) chromosomal duplication. C) genetic drift. D) natural selection. Answer: A 25) The frequency of homozygous dominant individuals in a population that is in HardyWeinberg equilibrium is equal to A) q or p. B) p2. C) 2pq. D) 2p. Answer: B 26) Which of the following terms represents the frequency of heterozygotes in a population that is in Hardy-Weinberg equilibrium? A) p B) q C) 2pq D) q2 Answer: C 27) Which of the following conditions would tend to make the Hardy-Weinberg equation more accurate for predicting the genotype frequencies of future generations in a population of a sexually reproducing species? A) a small population size B) little gene flow with surrounding populations C) a tendency on the part of females to mate with the healthiest males D) mutations that alter the gene pool Answer: B 28) Imagine that you are studying a very large population of moths that is isolated from gene flow. A single gene controls wing color. Half of the moths have white-spotted wings (genotype WW or Ww) and half of the moths have plain brown wings (ww). There are no new mutations, individuals mate randomly, and there is no natural selection on wing color. How will p, the frequency of the dominant allele, change over time? A) p will increase; the dominant allele will eventually take over and become most common in the population. B) p will neither increase nor decrease; it will remain more or less constant under the conditions described. C) p will decrease because of genetic drift. D) p will fluctuate rapidly and randomly because of genetic drift. Answer: B 29) The recessive allele of a gene causes cystic fibrosis. For this gene among Caucasians, p = 0.98. If a Caucasian population is in Hardy-Weinberg equilibrium with respect to this gene, what proportion of babies is born homozygous recessive and therefore suffers cystic fibrosis? A) (0.02)2 = 0.0004 B) 0.02 C) (0.98)2 = 0.9604 D) 2(0.02 × 0.98) = 0.0392 Answer: A 30) Genetic drift resulting from a disaster that drastically reduces population size is called A) natural selection. B) gene flow. C) the bottleneck effect. D) the founder effect. Answer: C 31) In populations of the greater prairie chicken in Illinois, genetic diversity was A) lost through mutation and restored by natural selection. B) lost through genetic drift and restored by natural selection. C) lost through gene flow and restored by mutation. D) lost through genetic drift and restored by gene flow. Answer: D 32) A population of 1,000 birds exists on a small Pacific island. Some of the birds are yellow, a characteristic determined by a recessive allele. The others are green, a characteristic determined by a dominant allele. A hurricane on the island kills most of the birds from this population. Only 10 remain, and those birds all have yellow feathers. Which of the following statements is true? A) Assuming that no new birds come to the island and no mutations occur, future generations of this population will contain both green and yellow birds. B) The hurricane has caused a population bottleneck and a loss of genetic diversity. C) This situation illustrates the effect of a mutation event. D) The 10 remaining birds will mate only with each other, and this will contribute to gene flow in the population. Answer: B 33) Thirty people are selected for a long-term mission to colonize a planet many light-years away from Earth. The mission is successful, and the population rapidly grows to several hundred individuals. However, certain genetic diseases are unusually common in this group, and the group's gene pool is quite different from that of the Earth population they have left behind. Which of the following phenomena has left its mark on this population? A) founder effect B) bottleneck effect C) high rates of mutation D) natural selection Answer: A 34) Genetic differences between populations tend to be reduced by A) gene flow. B) mutation. C) the founder effect. D) natural selection. Answer: A 35) Which of the following statements best describes the true nature of natural selection? A) Only the strongest survive. B) The strong eliminate the weak in the race for survival. C) Organisms change by random chance. D) Heritable traits that promote reproduction become more frequent in a population from one generation to the next. Answer: D 36) Which of the following will tend to produce adaptive changes in populations? A) genetic drift B) gene flow C) natural selection D) the founder effect Answer: C 37) An elk herd is observed over many generations. Most of the full-grown bull elk have antlers of nearly the same size, although a few have antlers that are significantly larger or smaller than this average size. The average antler size remains constant over the generations. Which of the following effects probably accounts for this situation? A) directional selection B) stabilizing selection C) a bottleneck effect that resulted in low genetic diversity D) a high rate of gene flow Answer: B 38) After a copper smelter begins operation, local downwind populations of plants begin to adapt to the resulting air pollution. Scientists document, for example, that the acid tolerance of several plant species has increased significantly in the polluted area. This is an example of A) stabilizing selection. B) disruptive selection. C) directional selection. D) genetic drift. Answer: C