Topic 2 Flashcards
what are the 5 agents of evolutionary change
- mutation
- gene flow
- non-random mating
- genetic drift
- selection
population definition
a localized group of interbreeding individuals
gene pool definition
a collection of alleles in the population
what is the difference between alleles and genes
a gene is a unit of hereditary information/ stretch of DNA on a chromosome
an allele is a version (sequence of variants) of a gene
allele frequency definition
says how common that an allele is in a population
how many A vs. a
evolution definition
change in allele frequencies in a population
what would make a population non-evolving
if you removed all agents of evolutionary change
- no genetic drift (too large of population)
- no migration (gene flow in-out)
- no mutation (no genetic change)
- random mating (no sexual selection)
- no natural selection (everyone is equally fit)
what is hardy weinberg equilibrium
hypothetic/non-evolving population (preserves allele frequencies)
serves as a null hypothesis model
natural populations are rarely in H-W equilibrium
why is hardy weinberg useful
it is a useful tool to measure if forces are acting on a population
it measures evolutionary change
in HW, what represents the frequency of dominant allele (A)
p
in HW, what represents the frequency of recessive allele (a)
q
HW equations
p+q=1
p^2 + 2pq + q^2 = 1
what represents homozygous dominant in HW
p^2
what represents homozygous recessive in HW
q^2
what represents the frequency of heterozygotes in HW
2pq
