4.1-4.3

Question 0

internal node

Answer 0

-nodes within phylogeny representing ancestral populations or species

Question 1

cladogram

Answer 1

-only show species and not period of time (but know general order of speciation events)

Question 2

node

Answer 2

• point in phylogeny where lineage splits

- speciation event

Question 3

tips

branches

Answer 3

• ends of phylogeny that represent species

- lineages evolving through time between successive speciation events

Question 4

clade

Answer 4

-an organism and all of its descendants

Question 5

monophyletic

Answer 5

-group of organisms in a clade

Question 6

synapomorphy

Answer 6

• shared derived character

- evolved in immediate common ancestor of clade and inherited by all descendants

Question 7

cladistics

Answer 7

-grouping clades according to synapomorphies (in phylogenetic trees)

Question 8

homoplasy

Answer 8

• from convergent evolution or evolutionary reversal

- character similarity NOT due to shared descent

Question 9

convergent evolution

Answer 9

• type of homoplasy

- independent origin of similar traits in separate lineages

Question 10

evolutionary reversal

Answer 10

• type of homoplasy
• reversion of derived character to its ancestral state
  eg. snakes lost limbs

Question 11

outgroup

Answer 11

• group of organisms (eg. species) which is outside of monophyletic group we are analyzing (but still closely related)
• used to infer ancestral characters