Lecture 26: Population: Evolution through time and space Flashcards
1
Q
What is a population?
A
- Localised group of individuals of the same species
2
Q
What is a gene pool?
A
- Total aggregate of genes in a population at one time
3
Q
What happens to allele frequencies in a population over time?
A
- They remain constant over time unless acted upon by evolutionary forces
4
Q
What are the assumption of the Hardy Weinberg Theorem?
A
- Large population size
- Random mating
- No migration
- No mutation
- No natural selection
5
Q
What is the Hardy Weinberg equation (for 2 alleles)?
A
- p^2 + 2pq + q^2 = 1
- remember q + p = 1
6
Q
Why is the H W equation important?
A
- This enables us to estimate proportions of genotypes and alleles in the population
7
Q
Allele frequencies do change via…
A
- Non-random mating
- Assortative mating
- Inbreeding
- Random genetic drift
- Bottleneck effect
- Founder effect
- Natural Selection
- Gene flow
- Migration
- Mutation
8
Q
What is random genetic drift?
A
- A random change in allele frequencies due to sampling error over generations
- Small sample of flowers
9
Q
What is a bottleneck effect?
A
- Original population has equal frequencies
- Population reduction / bottleneck event
- Surviving population has altered allele frequencies
10
Q
What occurs during selective selection?
A
- Headsize at birth
11
Q
What occurs during sexual selection?
A
- Females usually choose the males whom she wants to mate with
- Bird with glued on tail still desirable
- Elongated even more desirable
12
Q
What is frequency dependent selection?
A
- 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
13
Q
What is Cline?
A
- Gradual change in genetic make up proportions
- Clover + Cyanide
- No cyanide-y clover in Russia
