Ch 8

25 July 2022
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While on the voyage of the HMS Beagle, Darwin:
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nurtured his love of studying nature, exploring plant and animal diversity, and collecting fossils.
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Tiktaalik appears to:
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represent a transitional species, somewhere between fish and land animals.
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Which scientist is incorrectly matched to his scientific/evolutionary contribution?
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Georges Cuvier showed through genetic experiments that extinction had occurred.
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____________ selection favors organisms that have character values at both extremes of the phenotypic distribution.
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Disruptive
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Which of the following is a primary line of evidence demonstrating the occurrence of evolution?
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all of the above
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The chief concern among conservation biologists trying to protect small populations is:
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to preserve genetic diversity.
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In dry years in the Galápagos Islands, finches had to eat large, hard seeds. In wet years, however, finches could eat smaller, soft seeds. The alternation between dry and wet years in the habitat of these Galápagos finches illustrates that:
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natural selection does not march simply toward an optimized endpoint.
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It is said that the fossil record is an incomplete record. Why is that?
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Both the first and second choices best explain this statement.
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Which of the following best describes worldwide views before and after Darwin?
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BEFORE: A creator put all organisms on earth at the same time. AFTER: Over time, species evolved, but it all started with one organism.
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Adaptation:
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refers both to the process by which organisms become better matched to their environment and to the features of an organism that make it more fit than other individuals.
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Which of the following is incorrectly matched?
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molecular biology: examination of life at the level of atoms and compounds
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Which of the following work by earlier scientists was LEAST important for Darwin's development of the theory of evolution by natural selection?
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Wallace's discovery of distinct bioregions in the Malaysian archipelago
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Which of the following does NOT cause mutation?
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social influences
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The consistent accumulation of mutations that creates differences in the DNA sequences of two diverging groups of organisms is referred to as:
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molecular clock
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Maze-running behavior in mice:
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heritable trait
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Estimates of evolutionary relatedness based on a "molecular clock" are supported by:
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The first two choices support the molecular clock estimates of evolutionary relatedness.1
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The average time to death from starvation in a fruit fly is about 20 hours. Selecting for increased starvation resistance in fruit flies:
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can produce populations in which the average time to death from starvation is 160 hours.
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Consider a population of 5,000 garter snakes. Two hundred of those snakes split off from the population to a new habitat. When the original population dropped from 5,000 to 4,800, the allele frequencies of various genes changed. The evolutionary process that caused the change in allele frequencies in the original population is:
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migration
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Which of the following statements best describes artificial selection?
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Artificial selection still exhibits differential reproductive success; however, mating and crossing is directed by humans and not nature.
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The amino acid chains making up hemoglobin in different species:
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differ depending how long it has been since the species last shared a common ancestor.
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During genetic drift, where do the genes drift to?
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The genes do not drift at all—drift is a mathematical metaphor that means gene frequencies are unstable and drift from one number to another.
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Which of the following statements about the relationship between humans and evolution is FALSE?
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Because evolutionary processes are operating today just as they have been since life first appeared on earth, humans have not influenced evolutionary processes.
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Which of the following are true about marsupial mammals?
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first and fourth answer
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Which of the following statements about mutations is FALSE?
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Mutations always decrease an organism's fitness.
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In the 1790s, Georges Cuvier found the fossil remains of mastodons. This conflicted with the prevailing worldview in Europe because:
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it meant that extinction must occur, since nothing resembling mastodons existed on earth at that time.
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All northern elephant seals come from a very small genetic pool. This is because in the 1890s a large number of them were very quickly killed until their population size was reduced to only about 20 individuals. Though their population has since increased to over 30,000 individuals, all their genes have come from those 20 individuals. Which of the following population genetic concepts does this example represent?
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the bottleneck effect
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Which of the following statements is NOT consistent with evolution by natural selection?
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Individuals change during their lifespans to fit their environment better, and these changes can be inherited by their offspring.
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Which of the following types of selection is INCORRECTLY matched with its example?
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Stabilizing selection: Turkeys have been selected based on increased size of their breast muscles.
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In a population in which a trait is exposed to stabilizing selection over time:
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the mean stays approximately the same and the variation decreases.
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Which of the following is NOT an important reason that natural selection does not lead to perfect organisms?
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all of the above
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Based on the information given, which of the organisms described below most likely has the LOWEST fitness?
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a sterile organism that lives twice as long as the average longevity in its population
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In the early 1800s when Darwin was growing up, it would have been difficult to develop a theory about how populations change over time because:
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almost everyone believed that humans and all other species, once created, could not change.
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Among the following group of organisms, which of the following would be considered the "fittest" organism?
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a small black spider that hatches 100 spiderlings
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"Survival of the fittest" is a misleading phrase. Individuals with the greatest __________ ________ are the most fit in any population.
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reproductive output
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When a group of individuals colonizes a new habitat, this is likely to be an evolutionary event because:
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small founding populations are rarely genetically representative of the initial population.
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Which of the following statements about the relationship between humans and evolution is FALSE? Like all living things, humans are still evolving. Humans' ability to control pest populations makes us powerful agents of evolutionary change. Preferential sport hunting can change the phenotypic distribution of traits in the hunted population. Correct: Because evolutionary processes are operating today just as they have been since life first appeared on earth, humans have not influenced evolutionary processes. Because evolutionary processes are operating today just as they have been since life first appeared on earth, humans have not influenced evolutionary processes. Human activity has changed the rate of extinction of many other species.
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During gene flow, where do the genes flow to? The genes flow from a locus on one chromosome to a locus on another chromosome. The genes flow through cyberspace. The genes flow from a locus on one chromosome to another locus on the same chromosome. The genes do not flow at all—flow is a mathematical metaphor that means gene frequencies are unstable and are drifting from one number to another. Correct: The genes flow into and out of the population due to migration of individuals from one population to another. The genes flow into and out of the population due to migration of individuals from one population to another.
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Which of the following statements best describes artificial selection? Artificial selection is not something seen in everyday life; it is, however, studied in highly sophisticated research labs. Artificial selection results after a large catastrophe strikes a region and results in the death of >90% of the individuals in a population. Artificial selection does not produce variable offspring. Correct: Artificial selection still exhibits differential reproductive success; however, mating and crossing is directed by humans and not nature. Artificial selection still exhibits differential reproductive success; however, mating and crossing is directed by humans and not nature. Artificial selection results in greater numbers of mutated organisms due to its reliance on forced mutations.
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In dry years in the Galápagos Islands, finches had to eat large, hard seeds. In wet years, however, finches could eat smaller, soft seeds. The alternation between dry and wet years in the habitat of these Galápagos finches illustrates that: finches with larger beaks went extinct during wet years. in dry years, smaller beaks were selected for. finches with smaller beaks are more likely to mate with finches with larger beaks in dry years. Correct: natural selection does not march simply toward an optimized endpoint. natural selection does not march simply toward an optimized endpoint. natural selection does not differentiate between the amount of rainfall that occurs in the habitat of a species.
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Which of the following statements about Charles Darwin is INCORRECT?
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He influenced Malthus's ideas about the limits of population growth.
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A population is:
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a group of individuals who live in the same location and have the potential to interbreed
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While on the Beagle, Darwin was intrigued by glyptodonts because:
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they resembled a species that currently exsisted, but were much larger
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Which of the following does NOT describe a way that scientific understanding of the world has changed following the publication of The Origin of Species by Charles Darwin?
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Changes acquired by individuals during their lifetime are passed on to their offspring.
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If evolution has occurred:
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allele freq. have changed
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The origin of all genetic variation is:
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mutation
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In a given population, a few individuals may, by random chance, leave behind more descendants than other individuals. Thus, the genes of the following generation will have a higher proportion of the alleles of the "lucky" individuals. Which of the following concepts is this example representative of?
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genetic drift
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___________ can result from many processes, including ___________ and __________.
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evolution; mutation, immigration
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The graph above shows data on the average beak size in finches (across multiple years). Based on this graph, what seems to happen as the climate gets drier?
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Birds with larger beaks survive and reproduce better than birds with smaller beaks
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Exceptionally large babies increase a mother's mortality risk when giving birth and exceptionally small babies tend to die at birth or shortly afterward. For these reasons, birth weight in human babies is generally:
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subject to stabilizing selection.
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Which of the following is not a source of evidence demonstrating the occurrence of evolution? A. comparative anatomy and embryology B. the fossil record C. molecular biology D. biogeography E. All of the above are sources of evidence demonstrating the occurrence of evolution. Feedback
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e
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Estimates of evolutionary relatedness based on a "molecular clock" are supported by: A. the fossil record. B. observations of comparative anatomy. C. the mutation rate of other genes. D. Both A and B support the molecular clock estimates of evolutionary relatedness. E. All of the above support the molecular clock estimates of evolutionary relatedness. Feedback
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d
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Which of the following is an example of evolution by natural selection that has taken place over the last few decades in a manner that has allowed scientists to observe the evolutionary process? A. Insect wings evolved by first functioning as thermoregulatory organs, and slowly becoming flight organs. B. Honey-creepers on Hawaii have radiated into niches occupied by parrots and hummingbirds in other areas. C. Many strains of the bacterium Staphylococcus aureus have become resistant to penicillin. D. Blood-sucking bats retain their molars even though they have a completely liquid diet. E. All of the above.
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c
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What can be concluded about comparing differences in molecular biology between different species? A. Birds are more closely related to humans than dogs are. B. Genetic similarities demonstrate species relatedness. C. The longer two species have been evolving on their own, the fewer the genetic differences between them. D. Only DNA sequences can be used to compare relatedness between species. E. Extremely different species are fundamentally unrelated in any way.
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b