lecture 19- tree building and tree thinking Flashcards

1
Q

phylogenetic tree

A

visualizing relatedness of organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

node

A

point on phylogenetic tree showing two organisms share a common ancestor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

root to tip distance on phylogenetic tree

A

portrays the passage of time
fewer distances= more closely related= shorter root to tip distance to common ancestor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

history of aids

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

history of hiv: origins of strains

A

hiv is close to siv (disease impacting primates)

siv likely mutated into hiv and then entered the human population

phylogenetic trees are used to understand evolutionary origins and relationships of different hiv strains (hiv 1, america and hiv 2, west africa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

parsimony

A

take the most simplistic answer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

outgroup

A

nearby related but distinct species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

convergent evoluation

A

can lead to the emergence of traits multiple times in the phylogenetic treee

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

convergence

A

the process whereby distinct species independently evolve similar traits as a result of having to adapt to similar environments or ecological niches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

shared ancestry

A

share a common ancestor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

convergence

A

the tendency of unrelated animals and plants to evolve superficially similar characteristics under similar environmental conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

steps of drawing a phylogenetic tree

A

1) identify dna sites that differ between organisms
2) count dna differences between two organisms, do for all pairings between organisms to make full chart
3) identify closest pair (ones with least differences in chart)
4) draw closest pair into tree, separated by correct distance (Distance/2)
5) combine closest pair into one column and recalculate distances (average)
6) repeat tree drawing using next closest pair
7) repeat column combining with next closest pair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why might our tree differ from the accepted tree

A

1) we only used a small amount of dna sequence
2) we used dna sequence from one area of the genome
3) rates of dna sequence changes vary across the genome
4) rates of dna sequence changes vary between species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

why is 16s ribosomal dna useful to study the microbiome

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly