Deck 15: Extinction and Evolutionary Trends

Question 1

The probability of extinction via predation is NOT particularly high when

A) predator and prey have coevolved over long periods of time.
B) prey populations are stressed by additional environmental factors.
C) predators are a new arrival to the prey's habitat.
D) the prey species is long lived and has a low birthrate.

Answer 1

A

Question 2

Approximately what percentage of marine species was lost during the Permian extinction?

A) 40%-50%
B) 50%-60%
C) 70%-80%
D) 80%-90%

Answer 2

D

Question 3

Which statement best describes how our views on extinction have changed over the past several hundred years?

A) Our views have changed from denying that extinction ever took place to realizing that extinction occurs and Earth has experienced several mass extinction events.
B) Our views have changed from believing that extinctions never occurred to understanding that extinction does occur, but it is rare.
C) Our views have changed from believing that extinction never takes place to realizing that it only occurs sporadically, as evidenced by the mass extinction events in geologic history.
D) Our views have changed from believing that extinction never takes place to realizing extinction occurs at a constant rate across all taxa.

Answer 3

A

Question 4

Elevated levels of iridium are found in the geologic layer at the K-Pg boundary. Is this unusual?

A) Yes. Iridium is a common metal on Earth but rarely accumulates in a single layer.
B) No. Iridium is a rare element on Earth, but geological layers of iridium are not uncommon.
C) Yes. Iridium is a rare metal on Earth.
D) Yes. Composition differences between geological layers tend to equilibrate over time.

Question 5

Extinction of a species means that

A) all members of the species have died out and have left no descendants.
B) researchers are unable to find individuals of the species in nature.
C) members of the species are not reproducing.
D) the species has died out in part of its geographic range.

Question 6

Which of the following observations would be expected if an infectious disease were a contributor to amphibian decline?

A) Amphibian decline occurs simultaneously at many points throughout the entire range of amphibian populations.
B) Amphibian decline correlates with habitat alteration.
C) When transplanted into declining populations, individuals from healthy populations show the same symptoms as individuals from declining populations.
D) Symptoms of individuals from declining populations cannot be cured by medication.

Question 7

What particular trait made it more likely for a species to survive the Permian mass extinction?

A) adapted to low oxygen levels, known as hypoxia
B) adapted to living in the deepest part of the oceans
C) large in size
D) living underground

Question 8

A native species of wildflower belonging to the Asteraceae family only lives in the floodplains of the Illinois River in Illinois; in other words, it is native to only this one area of habitat. This species is ________ to this geographic area.

A) restricted
B) endemic
C) confined
D) limited

Question 9

For much of the Cretaceous, bivalves belonging to the Inoceramidae were among the most prominent bottom dwellers in aquatic communities, but then declined at the end of the Cretaceous, eventually going extinct. What does the figure tell us about the reason(s) the inoceramid species went extinct?

A) Shell deformities observed in fossils indicated a significant change in the chemistry of the oceans, which likely led to the extinction of the Inoceramidae.
B) Shell deformities observed in fossils indicated a significant increase in ocean temperature, which led to malformation of shells during development, causing the subsequent extinction of the Inoceramidae.
C) Shell deformities observed in fossils indicated a significant increase in predation, which likely led to the extinction of the Inoceramidae.
D) Shell deformities observed in fossils are difficult to interpret and could result from many factors.

Question 10

The graph shows the extinction rates for families of marine organisms over different periods of Earth's history. What is the best estimate for the background extinction rate given these data?

A) 14-20 families per million years
B) 8-12 families per million years
C) 2-5 families per million years
D) 2-20 families per million years

Question 11

The figure below shows the increasing morphological complexity in crustacean legs in 12 different phylogenetic comparisons. Why did the authors of this study choose to analyze the data independently for each comparison?

A) The lower sample size in each comparison makes for a more powerful statistical test.
B) This method allows testing for species selection within each of the 12 comparisons.
C) The observed pattern allows the exclusion of species selection as a possible evolutionary mechanism.
D) This method makes each comparison phylogenetically independent from the others.

Question 12

The graph shows extinction rates for families of marine organisms during different periods of Earth's history. How many mass extinction events do scientists commonly infer from these data?

A) 2
B) 13
C) 5
D) 3

Question 13

Which of the following is the greatest known mass extinction to date?

A) K-Pg
B) Permian
C) Triassic
D) Devonian

Question 14

Native plant A is endangered. You suspect that part of the reason for its decline is competition with an introduced exotic plant, B, which occupies a similar ecological niche. Which of the following experiments would NOT help you decide whether competition with B contributes to the decline of A?

A) Raise each species by itself in the absence of competition in a greenhouse, and measure growth and reproductive rates.
B) Establish experimental plots in which you remove plant B.
C) Count the number of seeds produced by A and B in nature.
D) Compare their DNA.

Question 15

Why are endemic species particularly at risk of extinction as a result of global climate change?

A) Endemic species occur predominantly in colder regions.
B) All endemic species have long generation times that make evolutionary adaptation to climate change prohibitively slow.
C) All endemic species are already stressed by other human impact.
D) Small and isolated geographic ranges make avoiding unfavorable climate conditions difficult.

Question 16

While studying a group of ammonites (an extinct lineage of cephalopods) that lived during the Mesozoic, you measure the shell diameter of different fossil ammonite species. The table represents the data you collected for each of six different time periods. To what rule does the data conform? $\begin{array} { | l | l | } \hline \text { Time interval } & \text { Mean shell diameter } ( + / - \text { standard error } ) \\\hline 245 - 214 \text { MYA } & 15 \mathrm {~mm} ( + / - 5 \mathrm {~mm} ) \\\hline 215 - 184 \text { MYA } & 21 \mathrm {~mm} ( + / - 7 \mathrm {~mm} ) \\\hline 185 - 154 \text { MYA } & 36 \mathrm {~mm} ( + / - 12 \mathrm {~mm} ) \\\hline 155 - 124 \text { MYA } & 63 \mathrm {~mm} ( + / - 21 \mathrm {~mm} ) \\\hline 125 - 94 \text { MYA } & 72 \mathrm {~mm} ( + / - 24 \mathrm {~mm} ) \\\hline 95 - 65 \text { MYA } & 84 \mathrm {~mm} ( + / - 28 \mathrm {~mm} ) \\\hline\end{array}$

A) biogenetic rule
B) Allen's rule
C) Cope's rule
D) Bergmann's rule

Question 17

Where would you place the actual extinction date of a taxon if you knew that the Signor-Lipps effect was at work?

A) exactly at the date of the last-known fossil
B) after the date of the last-known fossil
C) before the date of the last-known fossil
D) It is not possible to determine when extinction occurred relative to the date of the last-known fossil.

Question 18

Which mass extinction led to the disappearance of the dinosaurs?

A) K-Pg
B) Permian
C) Triassic
D) Devonian

Question 19

Which of the following conditions favors fossilization?

A) A dead organism remains exposed for a long time.
B) A dead organism is covered by soft sediment.
C) A dead organism is covered by water.
D) A dead organism is exposed to scavengers that clean the bones.

Question 20

What kinds of evolutionary trends are represented by each of the two diagrams below? The x-axis represents an arbitrary scale for a trait value, in this case eyespot diameter on a butterfly's wing. A


B

A) A = active trend; B = passive trend
B) A and B= active trend
C) A = passive trend; B =active trend
D) A and B = passive trend

Question 21

Explain how the figure suggests that extinction probability is independent of a taxon's age. Keep in mind that the y-axis is measured on a logarithmic scale.

Question 22

What does this figure tell about the differences in extinction probabilities between planktotrophic and nonplanktotrophic species? Planktotrophic


Nonplanktotrophic

A) Planktotrophic species tend to have relatively long durations and large geographic ranges, while nonplanktotrophic species have short durations and small geographic ranges.
B) Planktotrophic species tend to have relatively long durations and small geographic ranges, while nonplanktotrophic species have short durations and large geographic ranges.
C) Planktotrophic species tend to have relatively short durations and large geographic ranges, while nonplanktotrophic species have long durations and small geographic ranges.
D) Planktotrophic species tend to have relatively short durations and small geographic ranges, while nonplanktotrophic species have long durations and large geographic ranges.

Question 23

The history of life on Earth as recorded by fossil evidence of one type or another is referred to as

A) the fossil record.
B) carbonization.
C) Lagerstatten.
D) the law of superposition.

Question 24

You are a paleontologist studying the fossil marine fauna immediately after the K-Pg mass extinction. You find ammonite fossils in the post-K-Pg layer even though ammonites are believed to have vanished in the K-Pg extinction. You submit your sensational findings to a journal, but one of the reviewers questions your claim of ammonite survival. He points to the fact that your ammonite fossil was found in rock that shows extensive burrowing activity by benthic organisms. Why does the reviewer question your conclusion?

Question 25

What effect of mass extinctions is described by the expression "dead clade walking"?

Question 26

Alison Boyer (2008) analyzed data on the extinction of native birds in the Hawaiian Islands, particularly looking at extinctions resulting from two waves of human colonization. How did the patterns of extinction differ? A


B


C


D

A) The first wave of human colonization resulted in the extinction of large, flightless ground-nesting birds as a result of introduced predators, while the second wave resulted in the extinction of birds that fed on insects and nectar due to destruction of lowland forests.
B) The first wave of human colonization resulted in the extinction of birds that fed on insects and nectar due to destruction of lowland forests, while the second wave resulted in the extinction of large, flightless ground-nesting birds as a result of introduced predators.
C) In both waves of colonization, habitat destruction was responsible for the extinction of native Hawaiian birds, with large, flightless birds going extinct in the first wave and birds that eat insects and nectar going extinct after the second wave.
D) The first wave of human colonization resulted in the extinction of large, flightless ground-nesting birds as a result of hunting, while the second wave resulted in the extinction of birds that fed on insects and nectar due to destruction of lowland forests and introduced predators.

Question 27

Yellowstone National Park in the United States has a caldera, essentially a super volcano, lying beneath its picturesque surface. When the caldera erupts again, it will blanket all of North America in varying depths of volcanic ash in addition to temporarily changing the atmosphere for at least a decade. This alteration of continental ecosystems will likely result in the extinction of some species. Which of the following species would be the most likely to become extinct?

A) a flowering plant that is only distributed in Yellowstone and the states immediately surrounding the park
B) a salamander species endemic to the Ozark region of Missouri and known only from the Mark Twain National Forest
C) a species of chipmunk that lives in the upper Midwestern United States, including Yellowstone and the states adjacent to the park
D) white-tail deer, which have a broad range across the middle and eastern United States

Question 28

Why was the near extinction of all ocean plankton in the Permian mass extinction so devastating to marine species?

A) Plankton are the base of aquatic food chains.
B) Plankton provide oxygen for other aquatic species.
C) Without plankton sequestering carbon, an enhanced period of global warming caused ocean temperatures to increase.
D) The dead plankton smothered coral reefs, killing them, which was a critical loss of nursery habitat for most marine species.

Question 29

Leigh Van Valen (1973) tested the relationship between species longevity and extinction probability. Do these data support or reject the hypothesis that the longer a taxon has existed, the less likely it is to go extinct?

A) These data would support the hypothesis; there is a strong correlation between the age of the taxa and the probability of extinction.
B) These data would reject the hypothesis; there is no relationship between age of the taxa and the probability of extinction.
C) These data are inconclusive; the pattern of the relationship between taxa longevity and probability of extinction is unclear.
D) These data indicate that the opposite of the hypothesis is true, that longer-lived taxa are much more likely to go extinct.

Question 30

The earliest Homo sapiens fossils are about 200,000 years old. Could you use radiocarbon dating to determine the age of fossils from that period? Briefly justify your answer.

Question 31

The K-Pg extinction was likely the result of a catastrophic asteroid impact that resulted in an extinction that happened over a very short geological time period. How could the K-Pg impact cause the collapse of the global food chain that led to this mass extinction?

A) Flash fires resulting from the impact spread globally, putting significant amounts of smoke and particulate matter in the atmosphere, which reduced photosynthesis.
B) The particulate matter ejected from the impact created a significant amount of sedimentation that disrupted plankton production.
C) The impact created giant tsunamis that eliminated a vast amount of plant life as the waves impacted the continents.
D) Huge amounts of particulate matter were discharged into the atmosphere as a result of the impact, blocking sunlight and causing photosynthesis to plummet.

Question 32

A paleontologist collected fossils in the Grand Canyon and recorded the following data. $\begin{array} { | l | l | } \hline \text { Fossil ID } & \text { Depth from canyon rim } \\\hline \text { PCO3 } & 1,800 \mathrm {~m} \\\hline \text { B8B } & 75 \mathrm {~m} \\\hline \text { 22RD } & 1,757 \mathrm {~m} \\\hline \text { IT-O } & 757 \mathrm {~m} \\\hline \text { GH7 } & 293 \mathrm {~m} \\\hline\end{array}$
The oldest fossil collected is ________ while the youngest fossil collected is ________.

A) B8B; PCO₃
B) PCO₃; B8B
C) 22RD; B8B
D) IT-O; 22RD

Question 33

Which statement best describes the chain of events that indirectly led to the near extinction of Urocyon littoralis (island fox) in Roemer et al.'s 2002 study?

A) Feral pigs were introduced, golden eagles began feeding on the pigs, golden eagles then began attacking foxes, foxes nearly became extinct, and skunk populations increased.
B) Feral pigs were introduced, feral pigs began attacking foxes, golden eagles began feeding on pigs, skunk populations increased, and foxes nearly became extinct.
C) Golden eagles were introduced to control the feral pig population, golden eagles began feeding on pigs, golden eagles then began attacking foxes, foxes nearly became extinct, and skunk populations increased.
D) Feral pigs began competing with foxes for food, golden eagles began feeding on feral pigs, skunk population increases as feral pigs decrease, and fox population declines as their primary food source (feral pigs) declines.

Question 34

Fossil evidence from the Cambrian period indicated a large, rapid spike in speciation of marine species accompanied by increases in the number of genera and families. This would support which model of evolutionary change?

A) quantum theory
B) saltationism
C) punctuated equilibrium
D) phyletic gradualism

Question 35

Based on the fossil record, it was estimated that coelacanths had become extinct in the late Cretaceous, approximately 66 million years ago. However, a live coelacanth was discovered off the coast of South Africa in 1938. This is an example of

A) forward smearing.
B) the Signor-Lipps effect.
C) radiocarbon dating.
D) the law of superposition.

Question 36

Why would a paleontologist new to his or her profession who has decided to study human origins choose to focus his or her field work in Africa?

A) The vast majority of previous fossil finds regarding human origins have been discovered on the African continent.
B) The vast majority of Africa has not been explored for fossils of human ancestors; he or she would therefore be looking in areas where no one has found fossils before.
C) Although fossils of human ancestors have not been discovered on the African continent, DNA analysis of modern human genomes suggests they should be found there.
D) Due to political change, many nations in Africa are much easier to travel to than previously.

Question 37

Why do paleontologists find many more fossils of skeletal structures than remains of soft tissues?

A) Soft tissues cannot fossilize.
B) The hard parts of animals do not ever decompose, so they are more likely to be buried.
C) Scavengers typically eat the soft tissue, only leaving bones, teeth, and other hard structures.
D) Soft tissues rarely remain long enough to fossilize.

Question 38

Which of the following scenarios may produce an active trend in evolutionary change? Briefly justify your answer.
A. The mechanic stability of the exoskeleton of a group of terrestrial arthropods imposes an upper limit on the body size of these organisms.
B. The evolution of an endoparasitic lifestyle results in overall smaller body size as parasite species diversify to utilize small-bodied hosts, which are more common than large-bodied hosts.

Question 39

As a refuge manager for the US Fish and Wildlife Service, you have the difficult decision of selecting which refuges will be sold and put up for sale to be developed and which ones will be preserved. Selling refuge "A" will result in the loss of the Serpentes, the sale of refuge "B" will result in the loss of the Lacertoidae, and the sale of refuge "C" will result in the loss of the Tuataras. Based on phylogenetic history, you decide to save refuge "C" and have to explain to your supervisor why. Which statement best explains your decision?

A) Saving refuge "C" saves the greatest number of species in the phylogeny.
B) Saving refuge "C" saves the last two remaining species of tuataras, Sphendon punctatus and Sphendon gunther.
C) Saving refuge "C" saves the group with the deepest, oldest phylogenetic history.
D) Saving refuge "C" saves the greatest geographic area and is therefore likely to preserve all the groups on this phylogeny.

Question 40

In Chapter 5, one of the examples of evolution presented illustrated the changes in equine skull morphology that gradually led to the transformation of the ancestral species to a new equine species. What model of evolutionary change does this illustrate?

A) punctuated equilibrium
B) passive trend
C) phyletic gradualism
D) active trend

Question 41

Why is the Permian mass extinction event often referred to as an event where life almost died? What do scientists believe caused this event and why did it result in such a catastrophic loss of diversity?

Question 42

A biologist studying salamanders in Great Smoky Mountain National Park observes that several of his salamander populations are experiencing extirpation. If he wanted to determine if the extinction of these populations was related to an infectious disease or whether it was due to competition, for what patterns would he look?

Question 43

How did the cause(s) of the K-Pg extinction event differ from the Permian extinction? How were they the same?

Question 44

What factors help a paleontologist select sites for research?

Question 45

Explain the difference between preserving "species diversity" and preserving "phylogenetic diversity."

Question 46

Which figure illustrates phyletic gradualism and which figure illustrates punctuated equilibrium? How does the concept of evolutionary change differ between the two?

Question 47

Explain how forward smearing can result in an incorrect estimate of an extinction event.

Question 48

Describe the example of indirect effects on extinction studied by Roemer et al. (2001) in California's Channel Islands.

Question 49

What two evolutionary processes result in an active trend of evolutionary change?