Molecular evolution

Question 1

phylogenies:

Answer 1

• reflect patterns produced by evolution and reveal evolutionary relationships of organisms

Question 2

phylogenies model:

Answer 2

• evolution using relationships, morphology and DNA

Question 3

lineage:

Answer 3

series of organisms connected by genetic info passed form one generation to another

Question 4

common ancestor:

Answer 4

hypothetical organism that gave rise to different lineages

Question 5

sister taxa:

Answer 5

two lineages that share a common ancestor not shared by other groups

Question 6

phylogeny: tips

Answer 6

• leaves

- terminal lineage

Question 7

phylogeny: branch

Answer 7

line on a tree diagram representing lineage

Question 8

phylogeny: node

Answer 8

• point on phylogeny where one lineage splits into two

Question 9

list two methods of tree building:

Answer 9

• maximum parsimony

- maximum likelihood

Question 10

maximum parsimony:

Answer 10

tree with least number of overall changes (mutations) that explains the relationship of taxa

Question 11

maximum likelihood:

Answer 11

finds most probable tree given a model of DNA evolution

Question 12

monophyletic group (clade):

Answer 12

leaves which all share a common ancestor

Question 13

paraphyletic group:

Answer 13

all share common ancestor but left out one leaf

Question 14

polyphyletic group:

Answer 14

all leaves do not share common ancestor

Question 15

define character:

Answer 15

feature (usually morphological) that can be used to differentiate btw groups of organisms

Question 16

define shared ancestral character:

Answer 16

trait originated in ancestral organism

Question 17

define shared character:

Answer 17

evolutionary novelty within a clade

Question 18

define tree outgroup:

Answer 18

organism closely related to but not part of the species being investigated (ingroup)

Question 19

list types of phylogenies:

Answer 19

• cladogram
• phylogram
• chronogram

Question 20

define cladogram:

Answer 20

• represents relationships of taxa

- branch lengths are equal

Question 21

define phylogram:

Answer 21

represents rate of genetic change (scaled branch lengths) btw taxa

Question 22

define chronogram:

Answer 22

calibrated to time (fossil record)

Question 23

molecular clock:

Answer 23

• measures absolute time of evolutionary change based on regions of genome that appear to evolve at constant rates

Question 24

define assumption:

Answer 24

number of nucleotide substitutions is proportional to the time that has elapsed since divergence time (common ancestor)

Question 25

what do you calibrate molecular clock to:

Answer 25

fossil record

Question 26

use of molecular clock:

Answer 26

• estimate dates of events not known from fossil records

- approximation

Question 27

use of phylogenies:

Answer 27

• uncover evolutionary history of species
• identify novel and unique lineages
• conservation
• forensics