BIOL 180 Exam 3 TEST QUIZ GRADED A+ Q &
A MOD007 2023 ATESTED
What is a synapomorphy? correct answers A trait that is similar in two or more species because it is
derived from a trait that existed in a common ancestor.
Why do synapomorphies arise during evolution? correct answers When a new species begins evolving
independently, novel traits arise which are then passed on to its descendant species.
What does it mean to say that one phylogenetic tree is more parsimonious than another? correct
answers Fewer changes have to occur to make the origin of traits fit on the tree.
Is it correct to claim that traits always become more complex or specialized over time? correct answers
No, because it is common to observe that they don't.
What is a monophyletic group? correct answers a common ancestor and all of its descendants
What is an outgroup? correct answers a taxon that is closely related to a monophyletic group, but not
part of it
Homology and homoplasy produce similar traits. What is the key difference? correct answers whether
or not the similar traits were inherited from a common ancestor
What is a synapomorphy? correct answers a trait that is derived from an ancestor and identifies a
monophyletic group
As a principle in logic, what does parsimony mean? correct answers the simplest explanation is
preferred (more complicated explanations are less likely)
Why does convergent evolution occur? correct answers When natural selection favors similar traits in
similar environments.
On a phylogenetic tree, what does a branch represent? correct answers a population through time
On most phylogenetic trees, what does the length of a branch represent? correct answers nothing
On a phylogenetic tree, what does a node represent? correct answers a splitting event (one population
becomes two or more evolutionarily independent populations)
On a phylogenetic tree, what does a tip represent? correct answers any taxon (named group)
What criterion does the biological species concept use to identify species? correct answers reproductive
isolation
Which of the following is a strength of the biological species concept? correct answers It is focused on
genetic isolation—the key to speciation,
, Which of the following is a weakness of the biological species concept? correct answers It isn't
applicable to asexual, fossil, or geographically isolated species
Why is the morphological species concept a logical criterion for identifying species? correct answers If
species are evolving independently, they should have recognizable morphological differences
Which of the following is a strength of the morphospecies concept? correct answers It can be used with
fossil or asexually reproducing species, as well as sexually reproducing species.
Which of the following is a weakness of the morphospecies concept? correct answers Experts can
disagree about whether populations are similar enough to be the same species.
Why is genetic isolation--meaning, a lack of gene flow--required for speciation to occur? correct answers
Otherwise, gene flow will prevent populations from diverging (keep them alike).
What is a phylogenetic species? correct answers The smallest monophyletic group on a tree of
populations.
What is vicariance? correct answers A physical event that splits a population into two geographically
isolated groups.
In what sense is "disruptive selection" acting on apple maggot flies? correct answers Selection is
favoring individuals that prefer either apples or hawthorns--not both, or an intermediate.
Which of the following is NOT a key aspect of an adaptive radiation? correct answers It unfolds
gradually, in response to long-term environmental change.
How can morphological innovations trigger adaptive radiations? correct answers They allow organisms
to exploit resources in new ways.
How can ecological opportunity trigger adaptive radiations? correct answers They allow organisms to
exploit resources that are not being used by other organisms.
What is the logic behind the "new genes, new bodies" hypothesis for the Cambrian explostion? correct
answers New copies of genes that regulate development could make morphological innovations
possible.
What is the definition of a mass extinction? correct answers 60% of the species alive are wiped out in
less than 1 million years.
What's the major difference between background extinction and mass extinction? correct answers Mass
extinctions are intense but short-lived.
In terms of its impact on the array of species present, a mass extinction is most closely analogous to
which evolutionary force? correct answers drift (random changes in which species are present)
A MOD007 2023 ATESTED
What is a synapomorphy? correct answers A trait that is similar in two or more species because it is
derived from a trait that existed in a common ancestor.
Why do synapomorphies arise during evolution? correct answers When a new species begins evolving
independently, novel traits arise which are then passed on to its descendant species.
What does it mean to say that one phylogenetic tree is more parsimonious than another? correct
answers Fewer changes have to occur to make the origin of traits fit on the tree.
Is it correct to claim that traits always become more complex or specialized over time? correct answers
No, because it is common to observe that they don't.
What is a monophyletic group? correct answers a common ancestor and all of its descendants
What is an outgroup? correct answers a taxon that is closely related to a monophyletic group, but not
part of it
Homology and homoplasy produce similar traits. What is the key difference? correct answers whether
or not the similar traits were inherited from a common ancestor
What is a synapomorphy? correct answers a trait that is derived from an ancestor and identifies a
monophyletic group
As a principle in logic, what does parsimony mean? correct answers the simplest explanation is
preferred (more complicated explanations are less likely)
Why does convergent evolution occur? correct answers When natural selection favors similar traits in
similar environments.
On a phylogenetic tree, what does a branch represent? correct answers a population through time
On most phylogenetic trees, what does the length of a branch represent? correct answers nothing
On a phylogenetic tree, what does a node represent? correct answers a splitting event (one population
becomes two or more evolutionarily independent populations)
On a phylogenetic tree, what does a tip represent? correct answers any taxon (named group)
What criterion does the biological species concept use to identify species? correct answers reproductive
isolation
Which of the following is a strength of the biological species concept? correct answers It is focused on
genetic isolation—the key to speciation,
, Which of the following is a weakness of the biological species concept? correct answers It isn't
applicable to asexual, fossil, or geographically isolated species
Why is the morphological species concept a logical criterion for identifying species? correct answers If
species are evolving independently, they should have recognizable morphological differences
Which of the following is a strength of the morphospecies concept? correct answers It can be used with
fossil or asexually reproducing species, as well as sexually reproducing species.
Which of the following is a weakness of the morphospecies concept? correct answers Experts can
disagree about whether populations are similar enough to be the same species.
Why is genetic isolation--meaning, a lack of gene flow--required for speciation to occur? correct answers
Otherwise, gene flow will prevent populations from diverging (keep them alike).
What is a phylogenetic species? correct answers The smallest monophyletic group on a tree of
populations.
What is vicariance? correct answers A physical event that splits a population into two geographically
isolated groups.
In what sense is "disruptive selection" acting on apple maggot flies? correct answers Selection is
favoring individuals that prefer either apples or hawthorns--not both, or an intermediate.
Which of the following is NOT a key aspect of an adaptive radiation? correct answers It unfolds
gradually, in response to long-term environmental change.
How can morphological innovations trigger adaptive radiations? correct answers They allow organisms
to exploit resources in new ways.
How can ecological opportunity trigger adaptive radiations? correct answers They allow organisms to
exploit resources that are not being used by other organisms.
What is the logic behind the "new genes, new bodies" hypothesis for the Cambrian explostion? correct
answers New copies of genes that regulate development could make morphological innovations
possible.
What is the definition of a mass extinction? correct answers 60% of the species alive are wiped out in
less than 1 million years.
What's the major difference between background extinction and mass extinction? correct answers Mass
extinctions are intense but short-lived.
In terms of its impact on the array of species present, a mass extinction is most closely analogous to
which evolutionary force? correct answers drift (random changes in which species are present)
