Chapter 13
Population Genetics


A population is any group of members of the same species in a given geographical area.

Gene pool refers to the collection of all alleles in the members of the population.

Population genetics refers to the study of the genetics of a population and how the alleles vary with time.

Allele Frequencies

# of particular allele /total # of alleles

count both sets of the diploid chromosome  of each individual

Allele frequencies affect the genotype frequencies or the frequency of each type of homozygote and heterozygote in the population.

Phenotype frequencies

Frequency of a trait is determined from observation and varies in different populations.  i.e. PKU:  phenylketonuria, an inborn error of metabolism that causes mental retardation unless the person follows a special low protein diet from birth

 DNA finger printing techniques