Evolution and Ecology

Transcription

1 Evolution and Ecology REVIEW QUESTIONS Multiple Choice 1. Which of the following cannot be an example of evolution? a. As a consequence of legislation promoting cleaner air, the frequency of black peppered moths in Europe has decreased in the last half century. b. After repeated exposure to high temperatures, an individual turtle can tolerate heat more successfully. c. As a consequence of climate change, robins in the northeastern United States sing earlier in the spring than they did two decades ago. d. Due to a genetic bottleneck, the frequency of one allele has increased in a population of the fruit fly Drosophila subobscura. 2. Tall people generally have tall parents, and short people tend to have short parents. Based on this observation, we can infer that height is a. evolving in the human population. b. due to a single gene. c. a heritable trait. d. not a genetically-based trait. 3. Grasshoppers and crickets share many similar characteristics such as general body form, elongated hind wings (which they use for jumping), and particular wing structures. The simplest hypothesis that would explain the similarities between these insects is that they resulted from a. shared ancestry. b. gene flow. c. genetic drift. d. mutation. 4. Which process is the least likely to be the direct cause of appreciable change in allele frequencies over short periods of time? a. Mutation b. Genetic drift in small populations c. Gene flow d. Directional selection 5. Which of the following can produce new combinations of alleles in a population? a. Directional selection b. Stabilizing selection c. Genetic drift d. Recombination 6. After large seeds became more common, the average beak size of the medium ground finch increased in size over the course of a few years. This change was most likely a case of a. disruptive selection. b. directional selection. c. stabilizing selection. d. genetic drift. pg. 1

2 Human Impacts on Evolution 1. Trophy hunting in bighorn sheep has had an inadvertent evolutionary consequence: the sheep have become and their horns have become. a. larger; larger b. larger; smaller c. smaller; larger d. smaller; smaller The graphs below show the changes associated with the overall size of bighorn sheep (top), and the size of their horns (bottom) during the period between 1975 and According to the graphs, the sheep in 2005 on average weighed approximately than sheep weighed in a. 10 kg less b. 20 kg less c. 10 kg more d. 20 kg more 3. According to the graphs, the sheep in 2005 had horns that were approximately than average horn lengths found in sheep in a. 20 cm shorter b. 26 cm shorter c. 30 cm shorter d. 38 cm longer pg. 2

3 NATURAL SELECTION Refer to the diagram below showing four cases of selection on egg number in a population of flour beetles. The solid blue line represents the frequency of the original population, and the dashed red lines represent the frequency distributions after eight generations. 1. Which of the following most likely represents a case of disruptive selection? a. Graph A b. Graph B c. Graph C d. Graph D 2. Which of the following most likely represents a case of stabilizing selection? a. Graph A b. Graph B c. Graph C d. Graph D 3. Graph B most likely represents a case of a. stabilizing selection. b. directional selection. c. disruptive selection. d. increased mutation. pg. 3

4 4. In which case did the variance within the population for egg laying increase the most? a. A b. B c. C d. D 5. In which process do some individuals have heritable phenotypic traits that give them an advantage in either survival or reproduction? a. Directional selection b. Disruptive selection c. Genetic drift d. Both a and b 6. Which process changes allele frequencies by chance alone? a. Disruptive selection b. Stabilizing selection c. Genetic drift d. Both a and b 7. Which statement about genetic drift is false? a. It affects allele frequencies the most when populations are small. b. It can cause slightly deleterious alleles to be fixed in populations. c. It tends to decrease genetic variation within populations. d. It tends to decrease genetic differences among different populations. 8. What factor is important in minimizing the impacts of genetic drift? a. Mutation rate b. Population size c. Generation time of the organism d. None of the above; the effects of genetic drift are constant across all populations. 9. Which pair of evolutionary processes can introduce new alleles into a population? a. Mutation and recombination b. Genetic drift and recombination c. Disruptive selection and gene flow d. Gene flow and mutation 10. Suppose that several flies of a population that previously fed on blueberries start to feed on honeysuckle. Due to genetic differences that accumulate as the flies adapt to feeding on honeysuckle, these honeysuckle flies eventually breed earlier than the ancestral flies. This change most likely represents an early stage of speciation brought about by a. a geographical barrier. b. an ecological barrier (specifically temporal isolation). c. genetic drift. d. adaptive radiations. 11. As a habitat becomes fragmented, the population sizes of a species in the habitat should, effects of genetic drift should, and genetic variation within populations of this species should. a. increase; increase; increase b. increase; increase; decrease c. decrease; increase; decrease d. decrease; decrease; increase pg. 4

5 1. 4. Refer the figure below. You are studying a remote island before and after a volcanic eruption. Data at time 1 was collected one month before the eruption, and data at time 2 was collected one month after the eruption. All of the species on the island are endemic. The island is 100 km across. Species A and B (the two snail species) generally only move a distance of 2 m a day. Species C (the bird) often covers 20 km a day in search of food. After the eruption, the lava flow hardens, and the island is divided by a 20-km strip of bare rock with few if any resources these animals need to survive. Figure 1 1. Would you expect to see a change in patterns of gene flow in species B and C? Why or why not? 2. Deaths of individuals due to the volcanic eruption could change the frequency of alleles in these very small island populations. However, you do not have data on the allele frequencies before and after the eruption for any of these species. Based on your understanding of genetic change, do you expect that these three species would be affected by genetic drift? Why or why not? 3. Based on your knowledge of gene flow, genetic drift, and speciation, what do you predict will happen over the long term to these species? Do you predict that the current species will remain the same species, or do you think they might split? How would you be able to determine whether a species had split into two new species? 4. What is the most likely explanation for what happened to species A as a result of the volcanic eruption? pg. 5

6 Figure 2 Textbook Reference: Concept 6.4 Long-term patterns of evolution are shaped by large-scale processes such as speciation, mass extinction, and adaptive radiation Bloom s Category: 5. Evaluating 1. Which species is the oldest? What evidence do you have to support this? 2. Which two species are most closely related? What evidence do you have to support this? 3. Species D is no longer living. When could it have become extinct? 4. When did an adaptive radiation take place? 5. Suppose that species B, C, E, and F all share characteristics that are very different from those of species D, but there are currently no living species that fill the gap between the B/C/E/F group and species D. Now suppose you could team up with a paleontologist to look for fossils to better understand how B/C/E/F became so different from species D. What age of rocks would you look for to target your search? pg. 6