Lecture 7

Question 1

Fitness

Answer 1

how many genes are passed on compared to the successful population that have passed on their genes
- a relative quantity

Question 2

Selective advantage

Answer 2

the amount by which some individuals of a given genotype are better at adapting to an environment then others
- shows which one is fit or not
- saying AA has the highest advantage

Question 3

Adaptation

Answer 3

1. a trait that describes the fitness of an organism - are they better able to survive or adapt
2. the evolutionary process that leads to the maintenance of such traits
   -NS

Question 4

Natural selection on alleles

Answer 4

• positive selection/purifying selection
  -selection to maintain variation
• directional

Question 5

What are the models of selection

Answer 5

1. Stabilizing selection
2. directional selection
3. disruptive selection

Question 6

Stabilizing selection

Answer 6

the favoured traits are what the mean average is
- no extremes
- human birth weight

Question 7

Directional selection

Answer 7

shifts to either side of the extremes
- favours only one
- beak sizes for the finches
- depending on the drought - they either show a high freq of large beaks or small beaks
peppered moths

Question 8

Disruptive Selection

Answer 8

shifts to both extremes
- leads to trait divergence
- may lead to speciation
-

Question 9

How to study adaptations

Answer 9

1. study correlations in alleles
   - diversity over space and time
2. genes targeted by selection have to show distinctive patterns
3. experimental manipulations in a lab that force an adaption

Question 10

T/F
the peppered moth is an environmental adaptation correlation

Answer 10

true
due to the pollution in the environment
- there was directional selection to one of the extremes

Question 11

examples of environmental correlations to adaptation

Answer 11

toxicity evolved plants that have adapted to living in soil with heavy metals
- peppered moths due to pollution
-

Question 12

examples of genetic correlations to selection

Answer 12

G6PD - damages of RBCs
- when malaria is not present the favourability of this mutation goes down
(vice versa)

Question 13

Selective sweep

Answer 13

occurs when selection causes a new mutation to increase in frequency so quickly that nearby alleles hitchhike and also increase in frequency

Question 14

examples of lab approaches to adaption and selection

Answer 14

• E.coli experiment - freezing strains and growing more to be able to look back and compare to see evolution