Quiz_ EX Reading Assign. Quiz.pdf

1/31/24, 9:57 PM Quiz: EX Reading Assign. Quiz https://canvas.ubc.ca/courses/130808/quizzes/702648/take 1/16 EX Reading Assign. Quiz Started: Jan 31 at 9:27p.m. Quiz Instructions Please make sure you have read and completed the Worksheet before starting this submission. Get the Worksheet in pdf format or in docx format from the Homework (https://canvas.ubc.ca/courses/130808/modules/903620) module . This Reading Assignment Quiz is only a means of submitting your worksheet responses. This Reading Assignment explores global scale natural “disasters” or hazards, as well as objects that have impacted, or threaten to impact, our planet. We will first read and learn about the times of major extinctions and causes. Then we will access an article from a scientific journal to work through data that the authors have assembled on rates of extinctions. We will learn about the implications of these on the "sixth extinction". Finally, we will consider just one of the possible contributors to mass extinctions: meteor or asteroid impacts. 1 pts Question 1 The figure below is a “linear” geological time line presented in a circular format. You may see this or a similar depiction of geological time in class. Seven times are shown with small stars, and labelled A through G. At which of these times (i.e. which letter- labels) are each of the “big 5” extinction events?

1/31/24, 9:57 PM Quiz: EX Reading Assign. Quiz https://canvas.ubc.ca/courses/130808/quizzes/702648/take 2/16 Triassic–Jurassic or Tr-J E Permian–Triassic or P-Tr D Ordovician–Silurian or O-S B Late Devonian extinction or Late D C Cretaceous–Paleogene or K-Pg F 1 pts Question 2 From this figure, for roughly what proportion of Earth’s entire history did Earth experience the two periods of “snowball Earth”? 45% - 55% less than 3% 15% - 20%

1/31/24, 9:57 PM Quiz: EX Reading Assign. Quiz https://canvas.ubc.ca/courses/130808/quizzes/702648/take 3/16 85% - 95% 65% - 75% 25% - 30% 8% - 10% 1 pts Question 3 17 In total, how many extinction events are listed in that table? Answer with a number, NOT a word (e.g. ‘10’, not ‘ten’). 1 pts Impacts or “craters” 3 Changes in sea level, ocean chemistry or anoxia (not including “climate change” without sea-level changes) 2 Volcanic, flood basalt, magmatic provinces or “traps” events 1 Question 4 Below is a list of possible causes of extinctions that have been identified. Put these causes into order with “1” being MOST commonly identified and “3” being LEAST commonly identified. (If you need more information on one of the possible cause identified in the table, look it up!)

1/31/24, 9:57 PM Quiz: EX Reading Assign. Quiz https://canvas.ubc.ca/courses/130808/quizzes/702648/take 4/16 1 pts Question 5 What type of evidence is used to identify “extinction events”? HINT: This is NOT about evidence for how it happened but whether an “extinction event” occurred. Astronomical information such as evidence for supernovae, gamma ray bursts, etc. Geological evidence of impactors (asteroid or meteorite collisions with Earth) The fossil record Geological evidence of volcanic events Climate records (or proxies for climate variation) 1 pts Question 6 3 How many of all the extinction events (NOTE: The Great Oxygenation is not an extinction event.) in the table have at least one possible cause identified WITHOUT a reference or citation for that cause? Answer with a number, NOT a word (e.g. ‘10’, not ‘ten’). 1 pts Question 7 Rather than attributing widespread and rapid decrease in the biodiversity to a single cause, at least two types of causes seem to be necessary, each possibly including many factors. The first cause, long-term pressures on the ecosystem, called a press (one word only) by Arens and West, 2006 , make an ecosystem vulnerable. Then the second cause, a different set of more sudden changes, called a pulse (one word only), appears to tip the system into collapse.

1/31/24, 9:57 PM Quiz: EX Reading Assign. Quiz https://canvas.ubc.ca/courses/130808/quizzes/702648/take 5/16 1 pts Question 8 According to this short section, periods with more diverse ecosystems appear to be correlated with increasing rates at which species disappear. Also, periods with less diverse ecosystems appear to be correlated with increasing rates at which species appear. 1 pts Question 9 For which of the big 5 extinction events was the total number of genera the smallest just before the extinction? O-S Late D K-Pg Tr-J P-Tr 1 pts Question 10 What general lesson can be learned from this pair of figures by examining trends rather than the spikes representing extinction events? Earlier in time there seems to have been ______. lower diversity, and higher proportions of that diversity suffered in extinctions higher diversity, and lower proportions of that diversity suffered in extinctions

1/31/24, 9:57 PM Quiz: EX Reading Assign. Quiz https://canvas.ubc.ca/courses/130808/quizzes/702648/take 6/16 higher diversity, and higher proportions of that diversity suffered in extinctions lower diversity, and lower proportions of that diversity suffered in extinctions 1 pts Question 11 According to the data we are shown here, our planet suddenly lost over half of it’s marine genera ______ time(s) since 542 million years ago. 9 5 6 10 7 8 1 3 4 2 1 pts Question 12 In the abstract, the authors imply that background extinction rates are lower than their own estimate for average current rate of vertebrate species loss over the last century. If the authors had used even MORE conservative estimates for current rates of extinction, their result would have been higher than the estimate they gave.

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