Lesson 2 Evolution of population (microevolution) 1. A gene pool consists of a. all the aleles exposed to natural selection. b. the total of all alleles present in a population. c. the entire genome of a reproducing individual. d. the frequencies of the alleles for a gene locus within a population. e. all the gametes in a population. 2. In a population with two alleles for a particular locus, B and b, the allele frequency of B is 0.7. What would be the frequency of her erozygotes if the population were in Hardy-Weinberg equilibrium? a. 0.7 b. 0.49 c. 0.21 d. 0.42 e. 0.09 3. In a population in Hardy-Weinberg equilibrium, 16% of the individuals show the recessive trait. What is the frequency of the dominant allele in the population? a. 0.84 b. 0.36 c. 0.6 d. 0.4 e. 0.48. 4. The average length of jackrabbit ears decreases the farther north the rabbits live. This variation is an example of a. a cline. b. discrete variation. c. polymorphism. d. genetic drift. e. diversifying selection. 5. Which of the following is an example of polymorphism in humans? a. variation in height. b. variation in intelligence. c. the presence or absence of a widow's peak (see figure 14.14a) d. variation in the number of fingers. e. variation in fingerprints. 6. Selection acts directly on a. phenotype. b. genotype. c. the entire genome. d. each allele. e. the entire gene pool. 7. A founder event favors microevolution in the founding population mainly because a. mutations are more common in a new environment. b. a small founding population is subject to extensive sampling error in the composition of its gene pool. c. the new environment is likely to be patchy, favoring diversifying selection. d. gene flow increases. e. members of a small population tend to migrate.
8. In a particular bird species, individuals with average sized wings survive severe storms more successfully than other birds in the same population with longer or shorter wings. This illustrates a. the founder effect. b. stabilizing selection. c. artificial selection. d. gene flow. e. diversifying selection. 9. Compare and contrast the bottleneck effect and the founder effect as causes of genetic drift. 10. Which of the following is not capable of evolving? a. a population of fruit flies b. a population of asexually reproducing bacteria c. your professor d. the collective cats of a city e. a plant species that only reproduces asexually 11. Which of the following statements about evolution is false? a. Individuals evolve. b. Populations evolve. c. An entire species can evolve. d. Evolution involves a change of frequency of alleles in the gene pool. e. Evolution can proceed to a limited extent without the occurrence of mutation. 12. The only known population of a reptile species lives on an African mountain. No close relatives of this species are known. Suppose you could stop all mutations within the population and all immigration into or emigration out of this population. Which statement best describes the probable future of this population? a. All evolution will promptly cease. b. The population will deteriorate after a few generations because of excessive inbreeding. c. Evolution will continue as selection acts on the variability produced by sexual recombination of genes. d. Genetic drift will cause major evolutionary changes in the population. e. Although the population will cease to change it may survive for as long as the environment remains constant. 13. Which of these actually evolves? a. individuals b. populations c. species d. communities e. mutations 14. Which of the following categories is the smallest capable of evolution? a. Individual b. Population c. Species d. Community e. Family 15. Evolution is: a. A rare event b. Currently occurring only in scientific laboratories c. Constantly occurring at the same rate in ALL organisms d. A process that occurs as a result of differences in reproductive fitness e. A process that occurred only in the past 16. Evolution can be defined as:
a. A change in the genetic makeup of a population over time b. A change in form of an organism c. A change in the genetic makeup of an organism d. An organism growing into another type of organism e. One species diverging into two species 17. The gene pool for a particular gene is: a. All the alleles that occur in the population for all the genes b. All the alleles for a particular trait in all the individuals in the population c. The sum of all the heterozygous individuals d. The sum of all the homozygous individuals e. All the alleles for a given trait in a given individual 18. Mutations: a. Are random b. Occur to solve problems for species (are goal oriented) c. Can alone cause drastic changes in the gene frequencies of a population d. Only choices a and b are correct e. Are always detrimental 19. Mutations: a. Can be helpful or harmful b. Are very rare c. Must rely on natural selection to spread through a population d. Provide only the potential for evolution e. All of these 20. Populations of organisms are continually evolving which means... a. they are improving b. they are at equilibrium c. the are becoming more human d. they are getting bigger e. they are changing 21. If within a large population no mutations occur, no migration occurs, all matings are random, and each individual has an equal chance of reproducing, which of the following will probably happen? a. Extinction will occur. b. A bottleneck will occur. c. Natural selection will occur at the normal rate for that species. d. A change in allele frequency will lead to rapid evolution. e. No evolution will occur. 22. Equilibrium actually means... a. no change in allele frequency. b. no change in population size. c. equal numbers of p and q alleles. d. equal numbers of males and females. e. immigration is equal to emigration. 23. Which example is favored in terms of natural selection? a. a woman who lives 105 years and has 2 children b. a woman who lives 50 years and has 5 children c. a woman who lives 70 years and has 5 children d. a woman who lives 35 years and has 4 children e. a woman who lives 25 years and has 6 children
24. The sexual displays (like male deer fighting with each other), which are common during breeding season are: a. Frequently fatal due to the potentially lethal weapons (like sharp antlers) that are used by the combatants to gain access to the females b. Important in ensuring that mating is nonrandom c. Ritualized and rarely fatal despite the potentially fatal weapons used on these displays of strength and vigor d. Only choices a and b are correct e. Only choices b and c are correct 25. Which of the following would stop evolution by natural selection from occurring? a. if humans become extinct because of a disease epidemic. b. if a thermonuclear war killed most living organisms and changed the environment drastically c. if ozone depletion led to increased ultraviolet radiation which caused many new mutations d. if genetic recombination, sexual reproduction, and mutation stopped and organisms could only reproduce sexually 26. Most of the 700 species of fruit flies found in the Hawaiian archipelago are each restricted to a single island. One hypothesis to explain this pattern is that each species diverged after a small number of flies had colonized each new island. This mechanism is called: a. sexual selection b. genetic equilibrium c. disruptive selection d. the founder effect e. assortative mating 27. You are studying leaf size in a natural population of plants. The second season is particularly dry, and the following year the average leaf size in the population is smaller than the year before. But the amount of overall variation is the same and the population size hasn't changed. Also, you've done experiments that show that small leaves are better adapted to dry conditions than are large leaves. What has occurred? b. directional selection c. stabilizing selection d. the founder effect e. disruptive selection 28. Which of the following possibilities can be measured to estimate an organism's evolutionary fitness? a. the number of offspring it produces over its lifetime that survive to breed. b. the number of offspring it produces over its lifetime. c. the number of eggs it produces over its lifetime. d. the size of its offspring. e. the number of gametes it produces during the years when it is likely to be reproducing. 29. A city was intensively sprayed with DDT to control houseflies. The number of houseflies was immediately greatly reduced. Each year thereafter the city was sprayed again, but the flies gradually increased in numbers until ten years later they were almost as abundant as they were when the control program began. Which of the following most likely explains this? a. Flies from other areas moved in and replaced the ones killed by DDT. b. The few flies that were affected by DDT but survived developed antibodies to DDT which they passed on to their descendants. c. The DDT caused new mutations to occur in the surviving flies resulting in resistance to DDT. d. The DDT killed susceptible flies. The few that were already naturally resistant survived and passed this resistance on to their offspring. e. DDT is only affective in dry years. Eventually another very dry year will occur and DDT will again wipe out the flies in the city.
30. Imagine a population of monkeys in South America whose habitat has been reduced to the point where only 25 monkeys survive. This is an example of: b. founder effect c. natural selection d. population bottleneck 31. Genetic drift results in a change in gene frequencies because: a. gene flow within the population is less than gene flow between populations. b. reproduction is non-random within the population. c. the population size is so small that chance occurrences can alter gene frequencies. d. the population has not yet stabilized. e. the population is so large that natural selection has little noticeable affect. 32. Which of the following can cause evolutionary change? in a small population b. mutation c. non-random reproduction d. two of these are correct e. a, b, and c are all correct 33. Of the following mechanisms of evolution, which are at work in species that only reproduce asexually? a. gene flow b. genetic drift c. nonrandom mating d. mutation e. all these are activities in asexually reproducing species 34. Which of these is best considered the raw material of evolution? a. Non-random mating b. Natural selection c. Small populations with massive migrations d. Mutation e. Genetic drift 35. Evolution by genetic drift is most obvious in... a. large populations b. aquatic organisms c. small populations d. invertebrate species e. migratory species 36. Shrews have been documented to travel across frozen lakes and establish populations on previously uninhabited islands. This is an example of... b. founder effect c. population bottleneck d. coevolution e. divergent evolution 37. Imagine a population of monkeys in South America whose habitat has been reduced to the point where only 25 monkeys survive. This is an example of... b. founder effect c. natural selection
d. population bottleneck 38. Population bottlenecks are dangerous to a population because... a. inbreeding depression often results b. genetic variability is lost c. the potential for evolution is decreased d. a and b 39. Which of these decreases genetic variation in a population? b. gene flow c. mutation d. asexual reproduction e. equilibrium 40. What vital process (important to the evolutionary biology of a species) occurs when a young male baboon leaves the troop that he was born in to join another troop? a. Non-random mating b. Gene flow c. Formation of a large population d. Natural selection e. Genetic drift 41. Founder populations may quickly become very different from the parent population in a similar habitat due to... a. natural selection b. artificial selection c. bottleneck d. genetic drift e. mutation 42. The sexual displays and contests common in the Animal Kingdom (such as male Bighorn Sheep bashing their heads together) result in: a. Random mating b. Nonrandom mating c. Mutations d. Stabilizing selection e. Migraine headaches 43. The Pennsylvania Amish have a very high frequency of an unusual allele that results in short arms and legs and extra fingers. This high frequency is thought to be the result of: a. Founder effect b. Mutations c. Population bottleneck d. Continental drift e. All of these 44. The extreme loss of genetic diversity that has occurred in the northern elephant seal and cheetah populations is the result of: a. Founder effect b. Population bottleneck c. Continental drift d. Genetic drift e. Natural selection
45. Habitat loss is dangerous to a species because it can result in... a. migration b. population bottlenecks c. increased predation d. loss of parasites e. natural selection 46. A small population is likely to evolve because of, but this is not likely to be true for large populations. a. Sexual selection b. Genetic drift c. Mutations d. Nonrandom mating e. Natural selection 47. The most important kind of selection acting on a well adapted population in a relatively constant environment is: a. catastrophism b. directional c. stabilizing d. disruptive e. there is no kind of selection under these circumstances 48. Natural selection selects for or against... a. genotypes b. phenotypes c. gene pools d. populations 49. Which of these is a true statement? a. Natural selection causes genetic change in an individual. b. Natural selection causes genetic changes in populations. c. Evolution causes natural selection. d. Environmental change causes most heritable variations in an individual. e. Natural selection is the only mechanism for evolution. 50. As predator and prey species coevolve, which is a likely result of the process of evolution? a. Predator evolves which is non-selective when it kills prey (kills all ages, colors, sick and healthy with equal probability). b. Predator evolves which kills mostly individuals with some genotypes but not with other genotypes. c. Predators evolve which kill only the best (large and healthy) of the prey population. d. Predators play no role in evolution. e. Predators will learn to not eat that prey species; the predator and prey species become mutualists. 51. Which of these is not one of the major categories of natural selection? a. Directional b. Stabilizing c. Disruptive d. Polymorphic e. All are categories of natural selection 52. When a species lives within a constant environment for a long time the "average type" individual may have the best chance of survival and produce the most offspring. What type of selection is occurring? a. Polymorphic b. Disruptive
c. Stabilizing d. Directional e. Sedentary 53. Giraffe leg and neck length increased under selection, but currently is probably maintained by selection. a. polymorphic; disruptive b. directional; stabilizing c. disruptive; stabilizing d. stabilizing; disruptive e. disruptive; directional 54. The peacock's beautiful tail is really a trade-off between... a. kin selection and natural selection b. natural selection and genetic crift c. sexual selection and natural selection d. directional selection and natural selection 55. If two or more genotypes in a population are both favored by different selective forces, what happens? a. Balanced polymorphism b. Directional selection c. Stabilizing selection d. Migration e. It is impossible for two favored genotypes to exist within a population. 56. The very high frequency of the sickle cell allele in the African population is an example of: a. Stabilizing selection b. Directional selection c. Disruptive selection d. Repeated mutations e. Balanced polymorphism 57. Female Bobolinks tend to choose males who sing a familiar song. This is an example of... a. kin selection b. reproductive fitness c. inbreeding d. harem breeding e. sexual selection 58. A long-term, close relationship between two individuals of different species, which is beneficial to at least one of the individuals is: a. Predation b. Hedonistic c. Mutualism d. Symbiosis e. Altruism 59. Behavior that "costs" an individual but is beneficial to related members of the same species is: a. Symbiosis b. Altruism c. Mutualism d. Heterotrophic e. Competition
60. Which of these interactions affects natural selection? a. Competition b. Predation c. Altruism d. Parasitism e. All of these 61. A new predator is introduced and can feed on millipedes < 20mm long. No millipedes exceed 15mm in length. What will happen? a. All millipedes will be potential prey. b. Millipedes will mutate to be longer. c. Millipedes will evolve to eat the predator. d. Directional selection will favor 15mm millipedes. e. Directional selection will favor predators who consume the smallest millipedes. 62. In Central Africa the frequency (percent) of the sickle cell allele, compared to the normal allele, has remained stable over the years because the sickle cell allele protects against malaria. In the United States, malaria was eradicated shortly before WWII by eliminating the mosquito that spreads the disease. What has happened to the frequency of the sickle in African Americans living in the United States since the elimination of malaria? a. The frequency of the sickle allele has increased b. The frequency of the sickle allele has decreased c. The frequency of the sickle allele has not changed during this time period d. The sickle allele has disappeared from the African American population e. The normal allele has disappeared from the African American population. 63. The above described state of the sickle cell allele in African Americans since malaria was eliminated in the United States is an example of a. directional selection b. stabilizing selection c. disruptive selection d. genetic drift e. the founder effect ESSAY 64. Describe five mechanisms in which gene frequencies in a population can be altered. 65. Assume that protein synthesis always reads along a chromosome three bases at a time to code for each successive amino acid in a protein. There are two kinds of point mutations, a base substitution and a base deletion. How are these two types of mutations likely to affect the protein coded for by a mutated gene? 66. Explain why localized distributions and overspecialization can increase a species' probability of becoming extinct.