Chapter 26

Question 1

phylogenetic tree

Answer 1

branching diagram that shows the evolutionary history of a group of organisms

Question 2

sister taxa

Answer 2

groups of organisms that share an immediate common ancestor that is not shared by any other group

Question 3

rooted

Answer 3

a branch point within the tree represents the most recent common ancestor of all taxa in the tree

Question 4

basal taxon

Answer 4

a lineage that diverges from all other members of its group early in the history of the group

Question 5

clades

Answer 5

a group of common species, each of which includes an ancestral species and all of its descendants

Question 6

monophyletic

Answer 6

signifies that it consists of an ancestral species and all of its descendants

Question 7

paraphyletic

Answer 7

consists of an ancestral species and some, but not all, of its descendants

Question 8

polyphyletic

Answer 8

includes distantly related species but does not include their most recent common ancestor

Question 9

shared derived character

Answer 9

evolutionary novelty unique to a specific clade

Question 10

shared ancestral character

Answer 10

a character that originated in an ancestor of the taxon

Question 11

outgroup

Answer 11

a species or group of species from an evolutionary lineage that is closely related to but not part of the group being studied

Question 12

ingroup

Answer 12

the group of species being studied

Question 13

maximum parsimony

Answer 13

first investigate the simplest explanation that is consistent with the facts