BIOL 290 Lecture Notes - Lecture 6: Allele Frequency, Panmixia, Gene Pool
41 views1 pages
HWE
Wednesday, September 26, 2018
12:19 PM
• Each copy of a gene is an allele
• Population: a group of interbreeding individuals of the same species that exist together in a time
and space
• Gene pool: the set of ALL alleles in a population from all members of one generation, which can be
contributed to the members of the next generation
• Random- mating population: a population in which all possible matings between females and
males are equal in probability; contribute equally to the gene pool
• Condition
• Everyone has an equal chance of winning
• Examples of non-random mating
• Conditions for HWE:
1. Infinite population size: enormous; it effects what happens to allocation of alleles
2. Random mating
3. No selection; no fitness
4. No mutation; no new alleles
5. No migration
6. No genetic drift (random changes in allele frequencies)
Hardy Weinberg Equillibrium
1. With all conditions true, allele frequencies are constant, within and across generations
2. In any population, after 1 generation of random mating, genotypic frequencies are also constant
in further generations
3. Genotypic frequencies are a specific function of allele frequencies
• At hwe ONLY :
• The allele frequencies p and q for the population will remain constant from one generation to the
next
• The frequencies of genotypes A1A1, A1A2, A2A2 for this locus will also remain constant
• The genotype frequency after one generation of random mating can always be calculated from
allele frequency