L21 - population genetics and NS Flashcards
Hardy-Weinberg Equilibrium
*looks like punnett square
*looks at alleles in pop over time
*genotypic f: p2 + 2pq + q2 = 1
(p2 is the homo dom, 2pq are the hetero q2 is the homo recessive
Population
Localised group of individuals of the sane species
Gene pool
Total amount of genes in the population
Why do we need to estimate f of Genotypes in pop?
- Predict how many individuals will inherit a genetic disease
- estimate proportion of pop that will be carriers of the genetic disease
How to calculate allele f?
p + q = 1
Alllele frequencies change by:
Non - random mating
§ assortative mating
§ inbreeding
Random Genetic Drift
Bottleneck Effect
Founder Effect
Natural Selection
Gene Flow or Migration
Mutation
What is assortative mating
Attracted to similar phenotype
Disassortative mating
Attracted to a very different phenotype to your onw
inbreeding
leads to more homozygosity and legal recessives being expressed
Random genetic drift
Change in allele frequency due to random chance
effective pop
A small population
Bottleneck effect
A traumatic event that affects the allele frequency, new population recovers with alleles different to the og
Founders effect
A small pop moving to a new area bring their alleles that arent fully representative of the parental population
Stabilising selection
reduces variation but does not affect the mean
Directional selection
Moves towards one extreme of the curve
