Phylogenetic Trees

Question 1

phylogenetic tree

Answer 1

graphical summaries of the ancestor-descendent relationship among species (or populations)

Question 2

branch

Answer 2

represents a population through time

Question 3

root

Answer 3

most ancestral branch on the tree

Question 4

node

Answer 4

point within a tree where a branch splits into two or more branches

Question 5

nodes represent

Answer 5

MRCA - most recent common ancestor

Question 6

tip

Answer 6

living or extinct taxa

Question 7

sister taxa

Answer 7

any taxa derived from a common ancestral node

Question 8

polytomy

Answer 8

node with more than two descendent branches

Question 9

polytomy indicates

Answer 9

not enough information to determine which taxa are more closely related

Question 10

monophyletic group (clade)

Answer 10

ancestral group and all of its descendents (use snip test)

Question 11

how to determine which species are most closely related

Answer 11

taxa that share more recent common ancestor

Question 12

outgroup

Answer 12

species that is closely related to a group in study but not part of it

Question 13

ancestral trait

Answer 13

characteristic of the outgroup

Question 14

derived trait

Answer 14

modified trait from the outgroup

Question 15

synapomorphies

Answer 15

shared derived traits

Question 16

homoplasy

Answer 16

similarity in organisms due to reasons other than common ancestry (trait derives separately)

Question 17

convergent evolution

Answer 17

when two species or populations independently evolve the same trait

Question 18

analogous traits

Answer 18

functionally similar but independent evolutionary origin

Question 19

homology

Answer 19

similarity in organisms due to common ancester

Question 20

loss

Answer 20

a derived trait undergoes a reversal to the ancestral character

Question 21

SINEs

Answer 21

short interspaced nuclear elements - type of transposable element

Question 22

how are SINEs good evidence for phylogenies

Answer 22

chance of inserting SINE at exact same place is very low - species with SINE at same location share ancestry

Question 23

adaptive radiation

Answer 23

single lineage that leads to a diverse group of new species that are adapted to different habitats

Question 24

adaptive radiations have single

Answer 24

ancestral species - make a monophyletic group

Question 25

adaptive radiation indicates diversification from a

Answer 25

single origin

Question 26

adaptive radiations show rapid

Answer 26

speciation - small populations lead to opportunities for isolation

Question 27

adaptive radiations impact ecosystem by

Answer 27

filling many niches, having different roles in the ecosystem (evological diversification)

Question 28

adaptive radiation triggered by

Answer 28

ecological opportunity

Question 29

ways of taking advantage of ecological opportunity

Answer 29

invasive species, pioneer species, morphological innovations

Question 30

invasive species

Answer 30

new to an area - lack of natural predators

Question 31

pioneer species

Answer 31

first to be able to take advantage of an unused resource

Question 32

morphological innovation

Answer 32

development of new skill (ex. angiosperms)