Lecture 26: Population: Evolution through time and space

Question 1

What is a population?

Answer 1

• Localised group of individuals of the same species

Question 2

What is a gene pool?

Answer 2

• Total aggregate of genes in a population at one time

Question 3

What happens to allele frequencies in a population over time?

Answer 3

• They remain constant over time unless acted upon by evolutionary forces

Question 4

What are the assumption of the Hardy Weinberg Theorem?

Answer 4

• Large population size
• Random mating
• No migration
• No mutation
• No natural selection

Question 5

What is the Hardy Weinberg equation (for 2 alleles)?

Answer 5

• p^2 + 2pq + q^2 = 1

- remember q + p = 1

Question 6

Why is the H W equation important?

Answer 6

• This enables us to estimate proportions of genotypes and alleles in the population

Question 7

Allele frequencies do change via…

Answer 7

• Non-random mating
• Assortative mating
• Inbreeding
• Random genetic drift
• Bottleneck effect
• Founder effect
• Natural Selection
• Gene flow
• Migration
• Mutation

Question 8

What is random genetic drift?

Answer 8

• A random change in allele frequencies due to sampling error over generations
• Small sample of flowers

Question 9

What is a bottleneck effect?

Answer 9

• Original population has equal frequencies
• Population reduction / bottleneck event
• Surviving population has altered allele frequencies

Question 10

What occurs during selective selection?

Answer 10

• Headsize at birth

Question 11

What occurs during sexual selection?

Answer 11

• Females usually choose the males whom she wants to mate with
• Bird with glued on tail still desirable
• Elongated even more desirable

Question 12

What is frequency dependent selection?

Answer 12

• It pays to be rare
• The fish with left mouths = more rare
• So fish that are always being eaten from the left will always be on the lookout
• Like a zig zag

Question 13

What is Cline?

Answer 13

• Gradual change in genetic make up proportions
• Clover + Cyanide
• No cyanide-y clover in Russia