1 Geology 331: Questions for Test 1, Fall 2015 All test questions will be based on the following list of questions, except that additional questions may be asked about diagrams or figures from assigned readings, PowerPoint slides, and class handouts. Any of these questions may also be re-formatted into multiple-choice, matching, and fill-in-the-blank questions. Jackson, p. 2-9 When animals grow shells composed of calcium carbonate, what are the names of the two different minerals with this composition? Which of these two minerals is more readily dissolved after death and burial? The study of how living organisms become fossils is called __________? What is a fossil assemblage? In fossil preservation, what is the difference between permineralization and replacement? In fossil preservation, what is the difference between recrystallization and replacement? How is a fossil mold (or mould) formed? Adequacy of The Fossil Record Lectures, and reading from Kidwell and Sepkoski (1999) Draw a typical rarefaction curve of number of specimens (X axis) vs. number of species sampled (Y axis) and label that part of the curve where additional data provides diminishing information. What can be said about the quality of the fossil record at various taxonomic levels? Use rarefaction curves to illustrate your answer. Sketch and properly label the logarithmic decay model for the adequacy of the fossil record. What was the approximate number of marine fossil species described as of 1976? What is the approximate number of marine animal species alive today? What is the approximate number of marine animal species that may have lived in the geologic past? Round off to the closest million. According to calculations by Kidwell and Sepkoski that were reviewed in class, what percentage of marine animal species with hard parts are probably represented in the fossil record? How representative might this sample size be in describing patterns in the history of life? Explain your answer. How can we use spindle diagrams to understand patterns of diversity change in the fossil record of life? You may be asked to explain patterns for various spindle diagrams we reviewed in class, such as compare and contrast spindle diagrams between Bivalves and Trilobites. Be able to draw a simple spindle diagram for diversity changes through time. For example: Families of Corals: O, 3; S, 5; D, 12; C, 8; P, 2 Be able to answer basic questions about patterns of radiation, extinction, and evolutionary replacement on the crinoid diversity plots/graphs shown in class. Why do we look at the diversity data using plots of both counts and proportions (percentages)? Principles of Historical Geology & Geologic Time Scale Define the difference between relative and absolute geologic time. Define the principles of superposition, original horizontality, lateral continuity, cross-cutting relationships, and intrusive relationships. Know the different types of unconformities and how they are defined. Be able to work out the sequence of relative ages on a geologic cross section. Give an example of how the principles of historical geology can be used to find petroleum. What is William Smith known for? Geologic Time Scale: know it! 2 Radiometric Dating What are the two measurements needed for radiometric dating? For isotopes other than C14, what is the origin of radioactive isotopes in rocks? Define half-life. Sketch and label the curves of parent and daughter nuclides on a plot of half-lives vs. percent nuclides. If the parent:daughter ratio (P:D) of a radioactive isotope is 1:7 (1:15, etc.), how many half-lives have elapsed? Which decay constant is associated with a longer half-life? U235: 9.72x10-10 atoms per year; K40: 5.34x10-10 atoms per year Given the radiometric dating equation, t = (ln (P+D)/P)/be able to set it up to calculate a date if given information on P:D or D:P ratios, and the decay constant for a given radioactive element. For example, Pb207:U235 = 0.50 and U235: 9.72x10-10 atoms per year How is the radiometric clock set for isotopes in rocks? In radiometric dating, why are specific minerals used rather than whole rock analysis? How is the radiometric clock set for C14? What is the approximate maximum age for C14 dating? Give two examples of materials that can be dated with C14 dating. Explain in detail the methods used to determine that the first trilobites are 530 million years old, or that the last dinosaurs are 65 million years old. It is insufficient to simply state that radiometric dating is used. The late Famennian expansa conodont zone contains a volcanic ash layer dated at 363 Ma. The late Frasnian rhenana conodont zone contains a volcanic ash layer dated at 377 Ma. The early Famennian triangularis condodont zone does not contain any volcanic ash layers, but has been dated at approximately 375 Ma. Explain how was this done. If certain conodonts are found in a Late Devonian formation, and these conodonts are known to be from a particular biozone, how is it possible to say that biozone is 381 million years old? How old are the oldest rocks on earth? How was the true age of the earth determined at 4.55 Ga? Organization of Life and Biodiversity (class notes) What are the two domains of life? List the six kingdoms of the two domains of life. Know their domains. List 5 of the 10 phyla of animals that are common as fossils. List the major taxonomic categories, in order, of the Linnaean classification scheme starting with Kingdom. List three differences between prokaryotes and eukaryotes. What does a phylogenetic tree show? Give an example of a cnidarian. What are the Bilateria? What is the difference between Protostomia and Deuterostomia? (protostomes vs. deuterostomes) What is the difference between an inarticulate and an articulate brachiopod? Give an example of a class of molluscs. Give an example of a class of echinoderms other than crinoids. Homo sapiens is a member of which phylum? Give one example of an animal phylum with little or no fossil record. Explain why that is. Jackson, p. 10-20 List 3 items that you would take in the field when collecting fossils. 3 When collecting fossils in the field, why is it important to save both the part and counterpart of fossils in rocks? What is a horizon in sedimentary rocks? What is fossil curation, and why is it important? How is a Scanning Electron Microscope different from a Mass Spectrometer? Why is over collecting of fossils scientifically irresponsible? What is the science of taxonomy? What are holotypes and paratypes? What is the difference between the two? DK – Prehistoric Life, p. 30-31 How does Linnaean classification differ from Phylogenetic classification? Hint: which one is based on drawing evolutionary trees? Evolution (class notes) What are the two domains for the study of evolution? What was the name of Darwin’s most famous book? What are the three facts that lead to the conclusion: “Survival of the fittest?” What are the two sources of variation available to natural selection? What roles does sex play in evolution? Why were the Galapagos Islands a natural laboratory for Darwin to develop the Theory of Natural Selection? What are vestigial organs, and what is their significance? Give an example of an adaptive radiation. What are homologies? What is convergent evolution? Why has the number of species continued to increase over geologic time? Define allopatric speciation. What do sterile hybrids between closely related species tell us about the process of speciation? What is the role of geographic isolation in speciation? Define punctuated equilibrium both in words and with a labeled sketch. Define phyletic evolution or phyletic gradualism. Why do small populations evolve more rapidly than large populations? What is an evolutionary bottleneck? Why is a population bottleneck related to Punctuated Equilibrium? Give an example of evolutionary change operating in the present. What is the difference between microevolution and macroevolution? What are the four primary ways that the fossil record contributes to the understanding of evolution? What role do mass extinctions play in evolution over geologic time? DK – Prehistoric Life, p. 26-29 What is the definition of life? What is the definition of evolution? What drives evolution? How does speciation occur? Define the difference between microevolution and macroevolution with clear examples of each. Jackson, p. 21-31 Describe conditions during the Hadean part of Earth history. In which geologic eon did life appear on Earth? What are the oldest known fossils? 4 What does the appearance of the Cambrian Small Shelly Fossils indicate? What is a ‘living fossil’? What are stem groups on the ‘tree of life’? Why did Darwin’s book ‘The Origin of Species’ cause a storm of debate among scientists when it was first published in 1859? Give an example of gradual evolutionary change covered on page 28. What was the cause of the end-Ordovician mass extinction? Give two reasons for the Pleistocene mass extinctions of large mammals. Extinction List the five major mass extinctions in earth history. List a major taxonomic group that went extinct at the end of the Devonian; Permian; Cretaceous. List a major taxonomic group that nearly went extinct at the end of the Devonian; Permian; Cretaceous. The greatest reduction of trilobite orders was at the end of which geologic period? Which mass extinction event was the most extensive in earth history? Describe the difference between background extinctions and mass extinctions. Discuss the role of natural selection in both background and mass extinctions. Make a sketch showing the relative levels of O2 and CO2 in the atmosphere during the Phanerozoic. Describe the changes in the oceans and atmosphere associated with the Permian mass extinction. What were the possible killing mechanisms resulting from these changes? List five kinds of evidence for asteroid impact at the K/T boundary. What are the two major hypotheses for the primary killing mechanism associated with the K/T impact? What role might have infrared radiation played in the extinction of the dinosaurs? DK – Prehistoric Life, p. 32-33 How many mass extinction events can be linked to meteorite/asteroid impacts? Name them. What have scientists found at the Permian-Triassic boundary clays in Italy? Iron pyrites in marine sedimentary rocks in Greenland are evidence for what conditions associated with which mass extinction?