Chapter 23

Question 1

A cline is an example of what?

Answer 1

Geographic variation

Question 2

What 5 processes lead to micro evolution?

Answer 2

1. Mutations
2. Sexual reproduction
3. Natural selection
4. Gene flow
5. Genetic drift

Question 3

What are the types of genetic drift?

Answer 3

Founder effect and bottleneck effect

Question 4

What’s the only mechanism that leads to adaptive evolution?

Answer 4

Natural selection

Question 5

What are the 5 conditions in Hardy-Weinberg equilibrium?

Answer 5

1. No mutations
2. Random mating
3. No natural selection
4. Large population size (no genetic drift)
5. No gene flow

Question 6

What is relative fitness?

Answer 6

Contribution individual gives to gene pool of next generation (relative to others)

Question 7

Intrasexual selection vs intersexual selection

Answer 7

Intrasexual: members of one sex compete against each other
Intersexual: individual of one sex picky about choosing mate

Question 8

What are the 3 patterns of natural selection?

Answer 8

Directional, disruptive, stabilizing

Question 9

How is genetic variation preserved?

Answer 9

• Diploidy (hidden as recessive)

- Balancing selection (2 forms maintained)

Question 10

What are the 2 types of balancing selection?

Answer 10

1. Heterozygote advantage

2. Frequency-dependent solution (if phenotype is too common it will no longer be beneficial)

Question 11

Why can’t natural selection create perfect organisms?

Answer 11

• Only acts on existing traits
• evolution limited by historical constraints
• adaptions are often compromises
• chance, natural selection and environment interact

Question 12

What is average heterozygosity?

Answer 12

Percentage of heterozygous loci (measure of gene variability)