Lecture 8 - Population Genetics Flashcards
What is population genetics?
The study of allele frequency distribution and change under influence of the four main evolutionary processes:
- Genetic drift
- Natural selection
- Mutation
- Gene flow
What is evolution?
A change across generations in the frequencies of alleles.
What is population subdivision?
How genetic diversity is spread across a group of organisms.
What is a population?
A group of interbreeding individuals.
Who invented the Punnett Square?
Reginald Punnett
What is a punnett square used for?
To predict the genotypes amongst the offspring of a particular male and female.
In the Hardy-Weinberg equilibrium, what is
a) p?
b) q?
a) p = the frequency of one allele in the population (usually dominant)
b) q = the frequency of the other allele.
What is the equation for p?
p = 1 - q
What is the equation for q?
q = 1 - p
Give the Hardy Weinberg equation.
p^2 + 2pq + q^2 = 1
What does the Hardy Weinberg equation give you?
The frequencies of different genotypes expected to see in the offspring generation.
Give the Hardy-Weinberg assumptions.
- Organisms are diploid and sexual
- Allele frequencies are the same in each sex
- Mating occurs at random
- Population size is large, so no genetic drift
- No gene flow
- No mutations
- No selection
What is genetic drift?
Random changes in allele frequencies in small populations.
What is bottleneck?
Alleles are completely lost at random from a population, because there are very few of the alleles left.
What is the genetic marker of choice? What can it do?
- SNPs
- Can identify thousands of point mutations and can look at mutations across a whole genome.
