Lecture 7: Phylogenies

Question 1

If one combines speciation and natural selection over a long period of time, the net result is?

Answer 1

COMMON ANCESTRY

Question 2

Phylogeny

Answer 2

An evolutionary history of species or a group of species

Question 3

Branches

Answer 3

The lines of the phylogeny

Question 4

Node

Answer 4

The place where three branches connect to each other; points out common ancestors

Question 5

Tips

Answer 5

The trees endpoints (represent a living species)

Question 6

Outgroup

Answer 6

A taxon that is known to have split very early from the other taxa

Question 7

Poltyomy

Answer 7

A node that divides into more than one branch

Question 8

Homology vs Homoplasy

Answer 8

Homology: Similarity due to common ancestry
Homoplasy: Similarities NOT due to common ancestry

Question 9

Synapomorphy

Answer 9

A shared, derived trait

Question 10

Monophyletic groups

Answer 10

An evolutionary unit that includes an ancestral population and all of its descendants but no other

Question 11

Walter Fitch

Answer 11

Compared DNA sequeunces between organisms and used the information to determine phylogenic relationships

Question 12

What are the steps in comparing DNA

Answer 12

Step 1: Lign up the DNAS
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Step 2: Use the DNA sequences from different organisms and use the information to determine the phylogeny

Question 13

What gene is used when comparing DNA and used to construct the tree of life?

Answer 13

Ribosmal DNA gene

Question 14

What are the 3 reasons about why we should care about phylogenies?

Answer 14

1. Molecular phylogenies can solve difficult questions about particular species
2. Molecular phylogenies can solve difficult wuestions about broad patterns of evolution
3. You can solve cool problems