Lecture 22 Phylogenetics and Macroevolution

Question 1

Monophyletic group

Answer 1

group that includes the complete set of species derived from a common ancestor

Question 2

paraphyletic group

Answer 2

group that contains some but not all species derived from a common ancestor

Question 3

homology

Answer 3

similarity of traits due to common ancestry

Question 4

homoplasy

Answer 4

similarity of traits as a result of convergent evolution

Question 5

convergent evolution

Answer 5

the process whereby unrelated organisms share similar traits because they share similar ecological niches

Question 6

how do you tell what is more closely related to what is on a phylogenetic tree?

Answer 6

organisms that have a more recent common ancestor (vertice)

Question 7

what does a node represent on a phylogenetic tree?

Answer 7

the most recent common ancestor

Question 8

what are key innovations in phylogenetic trees?

Answer 8

traits that facilitate increased diversification rates and a decrease in extinction rate

Question 9

what is the benefit of key innovations?

Answer 9

carriers of the trait can exploit new resources and sets of habitats

Question 10

what is the most important thing to associate key innovations with?

Answer 10

rapid evolutionary diversification

Question 11

why do asexual species not survive as long as sexual species?

Answer 11

In an unstable or unpredictable environment, asexually-reproducing species may be at a disadvantage because all the offspring are genetically identical and may not have the genetic variation to survive in new or different conditions

Question 12

ancestral trait

Answer 12

a trait shared with a common ancestor

Question 13

derived trait

Answer 13

a trait that differs from the ancestral trait in a lineage

Question 14

what is a sister group on a phylogenetic tree?

Answer 14

Two descendants that split from the same node