Bio 345 Final Exam

Front 1

How often base substitution occurs depends on whether the mutation is:

Back 1

Neutral (no change in fitness)

Deleterious (Decreasing in fitness)

Beneficial/Advantageous (increasing fitness-positively selected)

Front 2

In any population with ____ size (N), a new neutral mutation can reach fixation by _______

Back 2

finite / genetic drift

Front 3

2N alleles at the locus, including _______, are ______ likely to be fixed in the future

Back 3

this new mutation / equally

Front 4

The fixation probability of a neutral mutation is _____

Back 4

1/(2N)

Front 5

If all mutations are neutral, the substitution rate per generation (k/t) is simply _______

Back 5

the mutation rate

Front 6

Neutral Mutations:

Relative fitness:
Fixation prob.:
Substitution rate per gener.:

Back 6

1

1/(2N)

mu

Front 7

Deleterious mutation:

Relative fitness:
Fixation prob.:
Substitution rate per gener.:

Back 7

1-s

0

0

Front 8

Beneficial Mutation

Relative fitness:
Fixation prob.:
Substitution rate per gener.:

Back 8

1+s

pfix >>1/(2N)
probability of fixation is high if the mutation is + selected

2N(mu)pfix>>(mu)
DNA seq evolves much faster than under genetic drift

Front 9

If all mutations are neutral:

The expected divergence :

Back 9

D=L x mu x 2t

L =sequence length (bp)
mu=mutation rate per bp
2t=divergence time

Front 10

Evolution of protein-coding seq:

First Kind

Back 10

1. Mutations that do not change amino acid sequence (mutations at synonymous sites)

No change in function of protein or in fitness

NEUTRAL mutations

Front 11

Evolution of protein-coding seq:

Second kind:

Back 11

2.Mutations that change amino acid sequence (nonsynonymous sites)

Either: Functional change-->No Fitness change --> Neutral (f0)

Or: Functional change--> Change in fitness--> deleterious (f1) or advantageous (f2)

or no/little functional change--> neutral (f0)

Front 12

f0 + f1 + f2 =

Back 12

1