Assignment 8 – Evolution and Natural Selection

Assignment 8 – Evolution and Natural Selection Use this image to answer the following 4 questions: 1) Which of the numbers in this tree represents the most recent common ancestor of amphibians and lizards? 2 2) An amnion is a shared homologous characteristic for which of the following lineages? Select all that apply. a) b) c) d) Mammals Crocodiles Amphibians lungfishes 3) Based on this tree, which of the following groups of organisms is most closely related to crocodiles? a) b) c) d) Hawks Lungfishes Mammals Lizards and snakes 4) What can you conclude about the lungfish lineage based on this tree? a) The most recent common ancestor of lungfishes and amphibians had digit-bearing limbs. b) The species designated by branch point 1 was a lungfish. c) Lungfishes do not share a common ancestor with the other lineages shown in this evolutionary tree. d) The most recent common ancestor of lungfishes and amphibians did not have an amnion. 5) Each of the following scenarios belongs under which of the appropriate field of evidence for evolution: A) Observation of Natural Selection in action; B) Fossil Evidence; C) Comparative Anatomy; D) Biochemistry (answers can be used more than once) ____b___ 1. Discovery of bones from many different dinosaur species ____c___ 2. Similar forelimb anatomy in different species of mammals ___a____ 3. Changes in average beak size in finches following dry or wet years ____a___ 4. Same genetic language of DNA and similar genes in yeasts, fruit flies, and humans ___a____ 5. development of pesticide resistance in insects ____a___ 6. Transitional forms that link whales with land-dwelling ancestors that are now extinct _____b__ 7. Discovery of shells of extinct species _____d__ 8. vestigial pelvis in right whales 6) Charles Darwin ___________ a) b) c) d) e) was the first person to conclude that organisms evolve proposed natural selection as the mechanism of evolution eagerly published his theory before it was well-developed was the first to realize that fossils are remains of ancient organisms proposed that unused parts of the body deteriorate 7) Which of the following observations would have helped Darwin shape his concept of descent with modification? a) Fewer species live on islands than on the nearest continents. b) Species diversity is lower farther from the equator. c) Birds live on islands located farther from the mainland than the birds' maximum nonstop flight distance. d) South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe. 8) What role does variation among individuals play in natural selection? a) The environment exerts pressure on individuals to vary their traits in order to make them better suited to their environment. b) Individuals that can vary their traits will reproduce more than those who cannot. c) Variability only occurs due to chance and cannot affect natural selection. d) Individuals with characteristics that more closely match their environment are more likely to survive and reproduce than those that are less well suited to the environment. 9) Which of the following pairs of structures are NOT homologous? a) wings of a flying fish vs. wings on birds b) wings of bats vs. arms of primates c) the neck of a giraffe vs. the neck of a dog d)the phospholipid bilayer in all animals 10) From his observations of organisms in the Galapagos islands, Darwin reasoned that _____. a) the organisms in the Galapagos had been specially created to thrive in that environment b) organisms had adapted to new environments, giving rise to new species c) the shape of a bird's beak does not affect its ability to survive and reproduce d) all island species should be similar to each other e) none of the above 11) Which one of the following researchers developed a theory of evolution that was very similar to Charles Darwin's? a) b) c) d) e) Lamarck Cuvier Lyell Hutton Wallace 12) A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of the fish are light brown, but about 10% are mottled. This fish species is often prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction of what will happen to this fish population? a) The proportion of mottled fish will likely increase over time. b) The ratios will not change. c) There is no way to predict the result. d) In two generations, all the fish will be mottled. e) As the mottled fish are eaten, more will be produced to fill the gap. 13) Which of the following is not an observation or inference on which natural selection is based? a) b) c) d) There is heritable variation among individuals. Species produce more offspring than the environment can support. Only a fraction of an individual's offspring may survive. Poorly adapted individuals never produce offspring. 14) Different finch species have beaks of different shapes and sizes. What do these beak differences tell us? a) Different finch beak shapes are evidence that finch species adapted to different environments over many generations. b) Different finch beak shapes are evidence that all Galápagos finches share a common ancestor. c) Different finch beak shapes are evidence that individual birds changed their beaks so that they could feed efficiently. d) Different finch beak shapes are evidence that several finch species with different beak types came to the Galápagos Islands from the mainland. 15) The wing of a bat is homologous to the _____ of a whale. a) b) c) d) e) baleen rib cage tail blowhole flipper 16) Varieties of Staphylococcus aureus that are resistant to the drug methicillin _____. a) b) c) d) developed in response to the use of methicillin already existed in the population before methicillin was developed always have an advantage in every environment were strongly selected for as methicillin became widely used to treat bacterial infections e) The second and fourth answers are correct. 17) Excavation of undisturbed layers of sedimentary rock in Africa reveals giraffe fossils varying in age (Table 1). Fossilized neck bones allow neck length to be determined, indicating that giraffes from 2000 years ago had shorter necks. Which statement best explains these results. Sedimentary Approximate Neck Length Layer Age (years) (meters) a) b) c) d) e) 1 500 1.9 2 1000 1.7 3 2000 1.6 The differences in neck lengths support Lamarck’s hypothesis. Environmental pressure resulted in giraffes with longer necks. The giraffes from the different layers are not related. Trees (giraffes eat Acacia tree leaves and twigs) were not as high 2000 years ago. This is an example of artificial selection. 18) The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data? a) Whales are not properly classified as mammals. b) Genes mutate faster in whales than in humans or bats. c) Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. d) Forelimb evolution was adaptive in people and bats, but not in whales. 19) DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that a) b) c) d) humans and chimpanzees share a relatively recent common ancestor. convergent evolution led to the DNA similarities. humans evolved from chimpanzees. chimpanzees evolved from humans.