8/31 notes

Question 1

phylogeny

Answer 1

a diagram depicting evolutionary relationships

Question 2

what does a phylogeny look like?

Answer 2

often looks like a tree, so it can also be called a phylogenetic tree

Question 3

speciation

Answer 3

through time, evolutionary lineages (species) can persist, go extinct, or give rise to new lineages

Question 4

tree parts

Answer 4

• node
• internode
• tip
• root
• outgroup
• ingroup
• polytomy

Question 5

groups

Answer 5

• monophyly
• clade
• paraphyly
• sister taxa

Question 6

trait similarity

Answer 6

• homology
• homoplasy
• coonvergence
• parallelism
• reversal

Question 7

types of traits

Answer 7

• apomorphy
• synapomorphy
• plesiomorphy
• symplesiomorphy

Question 8

apomorphy trait type

Answer 8

derived traits

Question 9

synapomorphy trait type

Answer 9

shared & derived traits

Question 10

plesiomorphy trait type

Answer 10

ancestral traits

Question 11

symplesiomorphy trait type

Answer 11

shared & ancestral traits

Question 12

common name for internodes

Answer 12

branches

Question 13

taxon

Answer 13

a formally named group of organisms such as a species, genus, or family

Question 14

nodes

Answer 14

branching points in a phylogenetic tree, most recent common ancestor of two or more groups

Question 15

what do nodes connect?

Answer 15

sister taxa

Question 16

what do nodes represent?

Answer 16

• ancestors
• where one lineage splits into two or more descendants

Question 17

how to interpret a tree

Answer 17

look for common ancestors and the descendants of those common ancestors

Question 18

clade

Answer 18

• all the descendants of a common ancestor
• also called monophyletic groups

Question 19

all extant members of a clade are …

Answer 19

equally related to the most common ancestor

Question 20

does rotating nodes alter relationships?

Answer 20

no

Question 21

does pruning a tree alter realtionships?

Answer 21

no

Question 22

can tree be drawn in different ways?

Answer 22

yes

Question 23

four main types of phylogenetic trees?

Answer 23

• diagonal up
• diagonal down
• rectangular
• circle

Question 24

hard polytomy

Answer 24

simultaneous divergence

Question 25

soft polytomy

Answer 25

unresolved relationships

Question 26

monophyletic group

Answer 26

all the descendants of a common ancestor

Question 27

another term for monophyletic group

Answer 27

clade

Question 28

paraphyletic group

Answer 28

an ancestor and some, but not all of its descendants

Question 29

if there is a problem with paraphyly, why does paraphyly persist?

Answer 29

- tradition - adaptive zones

Question 30

polyphyletic group

Answer 30

a group is not monophyletic and does not include the common ancestor. This is always a mistake, and the features used to define such groups are usually convergently evolved

Question 31

homology

Answer 31

a trait in two or more taxa that was inherited from a common ancestor

Question 32

homoplasy

Answer 32

similarity found in different species that is due to convergent evolution, parallelism, or reversal (not a common ancestor)

Question 33

short hand definition of homoplasy

Answer 33

false homology, or analogy

Question 34

the three causes of homoplasy

Answer 34

- convergent evolution - parallelism - reversal

Question 35

convergent evolution

Answer 35

similarity between species that is caused by a similar, but evolutionary independent, response to a common set of selection pressures

Question 36

parallel evolution

Answer 36

- convergent within a species or between closely related species - differs from convergent evolution because related species can take advantage of the same developmental mechanisms or gene flow

Question 37

homoplasy reversal

Answer 37

loss of a trait --> trait re-evolved

Question 38

homoplasy reversal example

Answer 38

larvae --> loss of larvae --> larvae re-evolved

Question 39

shared traits

Answer 39

present in two or more taxa

Question 40

derived traits

Answer 40

change from the ancestral condition

Question 41

synapomorphy

Answer 41

- shared, derived traits - provides evidence of common descent

Question 42

automorphy

Answer 42

- a derived character found in only one taxon in a tree - does not provide evidence for relationships

Question 43

plesiomorphy

Answer 43

- ancestral trait - shared ancestral characters are a means of phenotypic similarity, but do not provide evidence of common ancestor

Question 44

symplesiomorphy

Answer 44

a means of similarity, but does not define clades

Question 45

taxa defined by symplesiomorphy are often ...

Answer 45

paraphyletic

Question 46

the three kinds of similarity

Answer 46

- symplesiomorphies - synapomorphies - homoplasy

Question 47

only ________ provide evidence of _________________

Answer 47

evidence, common ancestry

Question 48

why phylogeny is hard to reconstruct

Answer 48

there are many ways to look similar, but only some kinds of similarity provide evidence for common ancestry