Lecture 3.1 Phylogenetic Trees

Question 1

Terminal taxa?

Answer 1

the relationship your trying to understand

Question 2

taxon?

Answer 2

any group that forms an unit of interest

Question 3

root of the tree?

Answer 3

common ancestor of all the terminal taxa in the tree

Question 4

node?

Answer 4

the most recent common ancestor of the taxa it connects

Question 5

lineage and divergence?

Answer 5

• a sequence of species that form a line of desecnt
• the relative timing of splitting events

Question 6

Clade?

Answer 6

a taxon that includes a common ancestor and all of its descendants

Question 7

sister taxa?

Answer 7

two taxa that are eachothers closest relatives

Question 8

Anagenesis?

Answer 8

Gradual change in a lineage over time

Question 9

Chanogenesis?

Answer 9

Evolution of an ancestral species into two descendant species

aka producing a new species increasing biodiveristy

Question 10

Monophyletic taxon?

Answer 10

Comprises one clade

Question 11

paraphyletic

Answer 11

includes a common ancestor and some, but not all, of its descendents

Question 12

polyphyletic

Answer 12

includes taxa from different clades, but not their most recent common ancestor

Question 13

Homologies

Answer 13

traits similar due to shared ancestor

Question 14

homoplasies

Answer 14

traits evolved independently in different lineages

Question 15

deuterostome

Answer 15

mouth second

Question 16

protosome

Answer 16

mouth first

Question 17

characteristics used to form phylogenies

Answer 17

Deveopmental

Behaviors

Molecular

Question 18

synapomorphies

Answer 18

derived state shared by two or more taxa

• jaws
• lungs
• claws/nails
• scales
• feathers…

Question 19

Ecosystem

Answer 19

Group of communities interacting with each other and with their shared physical (non-living) enviornment

Question 20

Biomes

Answer 20

Similar type of ecosystem distributed all over the world