Deck 27: Phylogenies and the History of Life

Question 1

Your professor wants you to construct a phylogenetic tree of orchids.She gives you tissue from seven orchid species and one lily.What is the most likely reason she gave you the lily?

A)to serve as an out-group
B)to see if it's a cryptic orchid species
C)to see if the lily and the orchids show all the same shared derived characters (synapomorphies)
D)to see if you were paying attention

Answer 1

A

Question 2

In plant communities today,leaf morphology is correlated with mean annual temperature,so paleobotanists use fossil leaf morphology to estimate the mean annual temperature of paleoclimates.However,the angiosperm fossil record contains an overabundance of samples fossilized near lakes or rivers where vines are especially common.Since vine leaves have a somewhat different association with temperature,use of data from vine-rich locations leads to mean average temperature estimates that are lower than actual recorded temperatures in modern plant communities.This potential bias in paleobotanical climate estimates is due to which type of bias in the fossil record? (R.J.Burnham,N.C.A.Pitman,K.R.Johnson,and P.Wilf.2001.Habitat-related error in estimating temperature from leaf margins in a humid tropical forest.American Journal of Botany 88:1096-1102.)

A)Taxonomic bias
B)Temporal bias
C)Habitat bias
D)Abundance bias

Answer 2

C

Question 3

Which of the following would be useful in creating a phylogenetic tree of a taxon?

A)morphological data from fossil species
B)genetic sequences from living species
C)gehavioral data from living species
D)all of the above
E)none of the above

Answer 3

D

Question 4

The Mesozoic era is nicknamed the Age of Reptiles and the Cenozoic era is nicknamed the Age of Mammals.What do these nicknames mean?

A)They indicate that the two eras are about the same length,because one lineage dominates the fauna of Earth only for a set period of time.
B)They identify the time of greatest diversity of these groups in the fossil record.
C)They identify the point of origin of these groups in the fossil record.
D)Both A and C are true.
E)Both B and C are true.

Question 5

You find a new fossil deposit,containing many species with shells but no soft-bodied species.What is the most logical conclusion?

A)There were no soft-bodied organisms at this time and location.
B)Conditions were not right to fossilize soft-bodied organisms.
C)There was a mass extinction event among hard-bodied,but not soft-bodied,species at this location.

Question 6

The phenetic approach to estimating phylogenetic trees is most like the approach of which species concept?

A)morphospecies concept
B)biological species concept
C)phylogenetic species concept

Question 7

Which of the following traits is useful in generating a phylogeny of species W,X,Y,and Z?

A)Trait 1
B)Trait 2
C)Trait 3
D)All of the above are useful traits.

Question 8

Which of the following statements best describes the rationale for applying the principle of parsimony in constructing phylogenetic trees?

A)Parsimony allows the researcher to "root" the tree.
B)Similarity due to common ancestry should be more common than similarity due to convergent evolution.
C)The molecular clock validates the principle of parsimony.
D)The out-group roots the tree,allowing the principle of parsimony to be applied.

Question 9

Some beetles and flies have antler-like structures on their heads,much like male deer do.The existence of antlers in beetle,fly,and deer species with strong male-male competition is an example of

A)convergent evolution.
B)a synapomorphy.
C)homology.
D)parsimony.

Question 10

Which of the following organisms would be most likely to fossilize?

A)a rare worm
B)a common worm
C)a rare squirrel
D)a common squirrel

Question 11

Which of the following would be least likely in the fossil record?

A)burrowing species
B)marine-dwelling species
C)marsh-dwelling species
D)desert-dwelling species

Question 12

Which of the following is an example of homoplasy?

A)fur in bears and seals
B)cell walls in plants and fungi
C)chlorophyll in flowering plants and algae
D)scales in snakes and lizards

Question 13

Which of the following statements is true about a phylogeny,as represented by a phylogenetic tree?

A)Descendant groups (branches)from the same node do not necessarily share any derived characters.
B)A monophyletic group can be properly based on convergent features in addition to synapomorphies.
C)The ancestral group is often identified by out-group analysis.
D)All of the above answers are correct.
E)None of the above answers are correct.

Question 14

Figure 27.1
Which of the following trees depicts the same relationship among species as shown above?

A)

B)

C)

D)None;the above trees all depict a different relationship among species.

Question 15

Figure 27.6
Applying the principle of parsimony to the trait "ability to fly," which of the two phylogenetic trees above is better?

A)Tree 1
B)Tree 2
C)Both trees are equally parsimonious.

Question 16

The cladistic approach to estimating phylogenetic trees is most like the approach of which species concept?

A)morphospecies concept
B)biological species concept
C)phylogenetic species concept

Question 17

Figure 27.7
For the streamlined bodies shown in Figure 27.7 above to be homologous instead of homoplasious,which of the following groups would also have to have streamlined bodies?

A)lizards and elephants
B)pterosaurs,dinosaurs,birds,and lizards
C)synapsids,monotremes,marsupials,elephants,primates,and rodents
D)all of the above
E)either B or C

Question 18

You have obtained the following data on genetic similarity among five species.The higher the number,the closer the relationship between the two species (so a species is related to itself 100%).What approach can you take to construct a phylogeny using these data?

A)Use phenetic analysis to cluster similar species.
B)Use cladistic analysis to infer the branching sequence.
C)Use parsimony to identify monophyletic groups.
D)None of the above answers is correct.

Question 19

Which listing of geological periods is in the correct order,from oldest to most recent?

A)Cambrian,Devonian,Permian,Cretaceous
B)Devonian,Cambrian,Permian,Cretaceous
C)Cambrian,Permian,Devonian,Cretaceous
D)Permian,Cambrian,Cretaceous,Devonian

Question 20

Figure 27.5
In the phylogenetic trees above,numbers represent species and the same species are shown in both trees.Which two species are represented as sister species in Tree 2 but are not shown as sister species in Tree 1?

A)1 and 2
B)2 and 3
C)3 and 4
D)6 and 5
E)The two trees show all the same phylogenetic relationships.

Question 21

A hypothetical island lies far from any other landmasses.There are many different types of plants,but only one animal-a beetle that can fly or walk from plant to plant and feeds by chewing leaves.Which morphological change would be most likely to trigger an adaptive radiation of the beetles?

A)a change in wing shape that improves flight speed
B)an additional segment on a pair of legs
C)a mouthpart that can pierce fruits and seeds

Question 22

Which of the following key adaptations is found in many animals from the Burgess Shale fauna,but not found in the Doushantuo and Ediacaran faunas?

A)mouthparts
B)segmentation
C)burrow formation
D)multicellularity

Question 23

The theory of plate tectonics describes movement of plates of the Earth's crust through time.Which of the following can you deduce from what you learned in this chapter about plate tectonics?

A)The continental plates have stopped moving,so continents are now in their final locations.
B)Some other organisms must have speciation patterns similar to those of ratites due to plate tectonics.
C)All distributions of animals on land can be explained by vicariance events due to past plate movements.
D)None of the above statements is true.

Question 24

Figure 27.9
What does the circled part of the phylogenetic tree above indicate?

A)an adaptive radiation
B)a mass extinction event
C)rapid speciation
D)A and C
E)all of the above

Question 25

The largest extinction,measured as a percentage of species that disappeared,occurred at the end of which geological period?

A)Permian
B)Cretaceous
C)Tertiary
D)Devonian
E)Silurian

Question 26

What is still lacking in the hypothesis of an asteroid impact as the cause of the end-Cretaceous mass extinction?

A)evidence of the location where an asteroid hit Earth
B)evidence that an asteroid hit Earth at the time of the extinctions (65 million years ago)
C)a convincing explanation of why mammals radiated after the event
D)a convincing explanation of why some lineages survived while others vanished

Question 27

Why would gene duplication events,such as those seen in the Hox gene complex,set the stage for adaptive radiation?

A)There are more copies of genes,meaning speciation had occurred by polyploidy.
B)The original gene copy is the out-group,and the new gene copies are the adaptive radiation.
C)Without duplicated genes,species would be vulnerable to extinction.
D)One copy of a gene can perform the original function while other copies are available to take on new functions.

Question 28

You are using a molecular clock to investigate how long ago two taxa diverged.In the sequence of mitochondrial DNA you are using,in one location an arginine mutated to a thymine;thousands of years later,it mutated from thymine back to arginine.What effect will this reversion to arginine have on your estimate of the time of divergence?

A)It will have no effect.
B)You will slightly overestimate the time since the two taxa diverged.
C)You will slightly underestimate the time since the two taxa diverged.

Question 29

You know that a particular stretch of DNA changes at the rate of 1 base per 10 million years.You sequence this length of DNA in two species and find that they differ by 4 bases: AATGCGATCG and AATGTTATGC.Based on these data,how long has it been since these two species diverged? (Hint: Ancestral sequence is AATGCTATGG.)

A)10 million years
B)20 million years
C)40 million years
D)100 million years

Question 30

Which statement best describes why the Cambrian explosion was important?

A)because good fossils from this period are available to study
B)because there was an explosion in animal abundance
C)because there was an explosion in ecological diversity among animals
D)because plant and animal fossils were found together for the first time

Question 31

Which of the following likely has the most Hox genes?

A)jellyfish
B)slugs
C)dolphins
D)bees

Question 32

Figure 27.8
The graphs above show percentage of change in three different molecular sequences plotted against time.Which of these molecular sequences would make a good candidate for a molecular clock?

A)Graph A,because the curve levels off over time
B)Graph B,because DNA is more important to organisms and,therefore,will give a more accurate picture of divergence
C)Graph C,because the change in sequence is the most rapid
D)Graph A or C,because changes in amino acid sequence are more likely to be neutral than changes in DNA
E)Graph B or C,because they are straight lines

Question 33

Deletions in mice in the Hoxa3 gene,on the A cluster,result in abnormal formation of glands in the neck.Deletions in the homologous Hoxd3 gene,on the D cluster,result in abnormal formation of the neck skeleton.The protein-coding sequences of Hoxa3 and Hoxd3 are about 50% the same.Researchers inserted a functional copy of the coding sequence of Hoxd3 in place of the coding sequence of a nonfunctional Hoxa3.They left all promoters,enhancers,splicing signals,and processing signals of Hoxa3 in place.Normal neck gland development was restored.What can you conclude? (J.M.Greer,J.Puetz,K.R.Thomas,and M.R.Capecchi.2000.Maintenance of functional equivalence during paralogous Hox gene evolution.Nature 403:661-65.)

A)The protein-coding sequence is most important in producing different functions.
B)Regulation of the genes is most important in producing different functions.
C)Either A or B could be true.

Question 34

Which value(s)would be required to calculate how long ago the most recent ancestor of ungulates lived?

A)the number of base pairs that differ among species in a certain genetic sequence
B)the total number of base pairs in the genetic sequence examined
C)the age of a fossil ancestor for calibration
D)All of the above

Question 35

To use a genetic sequence as a molecular clock,the changes in nucleotides in the sequence must have accumulated at a steady pace over time.Drawing on what you know about codons and redundancy in the genetic code,which type of change would most likely be the type that is useful for a molecular clock?

A)changes in the first nucleotide pair in the codon
B)changes in the second nucleotide pair in the codon
C)changes in the third nucleotide pair in the codon
D)All of these changes are equally useful for a molecular clock.

Question 36

How do mass extinctions differ from background extinctions?

A)Mass extinctions account for most species that have gone extinct in the history of life on Earth.
B)It is now recognized that mass extinctions but not background extinctions are generally caused by asteroid impacts.
C)Mass extinctions involve a relatively rapid extinction of a large proportion of organisms that were alive at that time.

Question 37

All of the following events can trigger an adaptive radiation except

A)a vicariance event splitting the habitat.
B)the evolution of a new morphological feature.
C)the colonization of a new habitat.
D)the extinction of competitors.
E)gene duplication events.

Question 38

Islands are well known for having many endemic species-species that are unique to that location.What is a likely explanation for this pattern?

A)Colonizers encounter fewer competitors on an island,so they can diversify.
B)Islands are more complex habitats than continents are,so they have more niches for specialization.
C)Humans bring partly or fully domesticated species with them when they arrive on islands.
D)The type of organism that is a good colonizer has more than the average amount of genetic variability,so it's more likely to speciate.

Question 39

Which of the following are typically responsible for island extinctions?

A)introduced species and habitat destruction
B)overharvesting and introduction of nonnative predators and herbivores
C)earthquakes followed by tsunamis
D)increased CO₂ levels and global warming

Question 40

What is thought to be the significance of the duplication of homeotic genes?

A)Compared to fish,the increased number of genes made evolution of the tetrapod foot possible.
B)Compared to jellyfish,the increased number of genes made evolution of more complex body forms possible.

Question 41

According to the phylogeny above,which of the following is true?

A)Chimpanzees are more closely related to humans than bonobos are.
B)Bonobos and chimpanzees are more closely related to each other than humans.
C)Chimpanzees and bonobos evolved from humans.
D)Chimpanzees and bonobos are more evolved than gorillas.

Question 42

Which of the following organisms would be most likely to fossilize?

A)a species of rat that lives in the desert
B)a species of clam found in a shallow marine habitat
C)a species of slug that lives in the rain forest
D)a species of flower found in Ontario forests

Question 43

Dicynodonts were pig-sized reptiles that lived during the Permian geologic period.An increase in dicynodont species diversity occurred soon after the Permian extinction.Given what you know of this period,this increase in dicynodont species diversity represents ________,most likely due to ________.

A)competitive exclusion;the fact that they needed new food sources
B)adaptive radiation;a morphological innovation among dicynodonts
C)adaptive radiation;the availability of previously unoccupied niches
D)competitive exclusion;intrasexual selection leading to anagenesis