2026\2027 A+ Grade
What is a synapomorphy?
- correct answer 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 answer 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 answer 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 answer No, because it is common to observe that they don't.
What is a monophyletic group?
- correct answer a common ancestor and all of its descendants
What is an outgroup?
- correct answer 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 answer whether or not the similar traits were inherited from a common ancestor
What is a synapomorphy?
- correct answer a trait that is derived from an ancestor and identifies a monophyletic group
As a principle in logic, what does parsimony mean?
- correct answer the simplest explanation is preferred (more complicated explanations are less likely)
, Why does convergent evolution occur?
- correct answer When natural selection favors similar traits in similar environments.
On a phylogenetic tree, what does a branch represent?
- correct answer a population through time
On most phylogenetic trees, what does the length of a branch represent?
- correct answer nothing
On a phylogenetic tree, what does a node represent?
- correct answer a splitting event (one population becomes two or more evolutionarily independent
populations)
On a phylogenetic tree, what does a tip represent?
- correct answer any taxon (named group)
What criterion does the biological species concept use to identify species?
- correct answer reproductive isolation
Which of the following is a strength of the biological species concept?
- correct answer It is focused on genetic isolation—the key to speciation,
Which of the following is a weakness of the biological species concept?
- correct answer It isn't applicable to asexual, fossil, or geographically isolated species
Why is the morphological species concept a logical criterion for identifying species?
- correct answer If species are evolving independently, they should have recognizable morphological
differences
Which of the following is a strength of the morphospecies concept?
- correct answer It can be used with fossil or asexually reproducing species, as well as sexually
reproducing species.