1. Phylogeny and the Tree of Life
Phylogeny and the Tree of Life

2. Which of the following taxonomic categories includes the fewest number of species?
Animalia
Panthera
Felidae
Carnivora
Mammalia
Answer: B

3. Which of the following taxonomic categories includes the fewest number of species?
Animalia
Panthera
Felidae
Carnivora
Mammalia 3

4. Animals that possess homologous structures probably _____.
evolved from the same ancestor
are headed for extinction
by chance had similar mutations in the past
are not related
have increased genetic diversity
Answer: A 4

5. Animals that possess homologous structures probably _____.
evolved from the same ancestor
are headed for extinction
by chance had similar mutations in the past
are not related
have increased genetic diversity 5

6. Which of the following would make the most suitable outgroup species for a cladogram relative to all the other species?
frog
tuna
snake
penguin
bat
Answer: B
The other choices are descended from terrestrial vertebrates. 6

7. Which of the following would make the most suitable outgroup species for a cladogram relative to all the other species?
frog
tuna
snake
penguin
bat 7

8. Which principle is not used to identify phylogenetic relationships?
maximum parsimony
Occam’s razor
maximum likelihood
minimum analogy
Answer: D 8

9. Which principle is not used to identify phylogenetic relationships?
maximum parsimony
Occam’s razor
maximum likelihood
minimum analogy 9

10. Given the DNA sequence data in the table, which phylogenetic tree is the most parsimonious?
Answer: A 10

11. Given the DNA sequence data in the table, which phylogenetic tree is the most parsimonious?11

12. Which of the following is the correct way to write the scientific name for humans?
Homo sapiens
homo sapiens
Answer: C
The name should be written in italics with the genus capitalized and the species lowercase. 12

13. Which of the following is the correct way to write the scientific name for humans?
Homo sapiens
homo sapiens 13

14. When describing a group of animals, you speak about an ancestral species and some but not all of its descendants. This is an example of a
monophyletic group.
polyphyletic group.
paraphyletic group.
Answer: C
A monophyletic group is an ancestor and all of its descendants, and a polyphyletic group is a group that has multiple ancestors. 14

15. When describing a group of animals, you speak about an ancestral species and some but not all of its descendants. This is an example of a
monophyletic group.
polyphyletic group.
paraphyletic group. 15

16. Hair on mammals when compared to other vertebrates is an example of a
shared derived character.
shared ancestral character.
paraphyletic character.
polyphyletic character.
Answer: A
Hair is something that only mammals share, and it is not found in their ancestors. If it were, then we would call it a shared ancestral character. 16

17. Hair on mammals when compared to other vertebrates is an example of a
shared derived character.
shared ancestral character.
paraphyletic character.
polyphyletic character. 17

18. Which of the following broad taxonomic groups is not one of the three domains of life?
Bacteria
Archaea
Plantae
Eukarya
Answer: C 18

19. Which of the following broad taxonomic groups is not one of the three domains of life?
Bacteria
Archaea
Plantae
Eukarya 19

20. Scientific Skills Exercise
Researchers have long debated different hypotheses for the phylogeny and classification of species in the bear family, Ursidae. In 2008, researchers obtained complete mitochondrial DNA (mtDNA) genome sequences for the eight living species of bears. Based on these data, the researchers constructed a phylogenetic tree for the family Ursidae. (See next slide.)

22. Which branch point represents the most recent common ancestor of all bears?
The most recent common ancestor to all living bears is not shown in this tree.
Answer: A

23. Which branch point represents the most recent common ancestor of all bears?
The most recent common ancestor to all living bears is not shown in this tree.

24. Which branch point represents the most recent common ancestor of the sloth bear and the spectacled bear?
branch point 1
branch point 2
branch point 3
The sloth bear and the spectacled bear do not share a common ancestor.
Answer: B

25. Which branch point represents the most recent common ancestor of the sloth bear and the spectacled bear?
branch point 1
branch point 2
branch point 3
The sloth bear and the spectacled bear do not share a common ancestor.

26. Which branch point represents the most recent common ancestor of the Asian black bear and the brown bear?
branch point 2
branch point 3
branch point 4
branch point 5
Answer: C

27. Which branch point represents the most recent common ancestor of the Asian black bear and the brown bear?
branch point 2
branch point 3
branch point 4
branch point 5

28. Which species is the basal taxon in this tree?
the polar bear
the spectacled bear
the sloth bear
the giant panda
Answer: D

29. Which species is the basal taxon in this tree?
the polar bear
the spectacled bear
the sloth bear
the giant panda

30. Identify the sister taxon to the polar bear.
the brown bear
the ancestor represented by branch point 7
the Asian black bear
the American black bear
Answer: A

31. Identify the sister taxon to the polar bear.
the brown bear
the ancestor represented by branch point 7
the Asian black bear
the American black bear

32. According to this tree, is the sun bear more closely related to the sloth bear or the polar bear?
The sloth bear and the polar bear are equally distant relatives of the sun bear.
Answer: A

33. According to this tree, is the sun bear more closely related to the sloth bear or the polar bear?
The sloth bear and the polar bear are equally distant relatives of the sun bear.

34. The tree includes the most recent common ancestor of all living species of bears (branch point 1). What does this tell you about this phylogenetic tree?
This phylogenetic tree contains homoplasies.
This phylogenetic tree is rooted.
The Ursidae family is a paraphyletic group.
The Ursidae family is a polyphyletic group.
Answer: B

35. The tree includes the most recent common ancestor of all living species of bears (branch point 1). What does this tell you about this phylogenetic tree?
This phylogenetic tree contains homoplasies.
This phylogenetic tree is rooted.
The Ursidae family is a paraphyletic group.
The Ursidae family is a polyphyletic group.

36. Which of the following groups of species is a monophyletic group, or clade?
all species of living bears
brown bear, polar bear, ancestral species 4, ancestral species 7
sun bear, Asian black bear, American black bear, ancestral species 5, ancestral species 6
sun bear, sloth bear, spectacled bear
Answer: C

37. Which of the following groups of species is a monophyletic group, or clade?
all species of living bears
brown bear, polar bear, ancestral species 4, ancestral species 7
sun bear, Asian black bear, American black bear, ancestral species 5, ancestral species 6
sun bear, sloth bear, spectacled bear