Introduction to Population and Evolutionary Genetics

Variability and Gene (or Allelic) Frequencies

• Genetic data for a population can be expressed as gene or allelic frequencies
• All genes have at least two alleles
• Summation of all the allelic frequencies for a population can be considered a description of the population
• Frequencies can vary widely among the alleles in a population
• Two populations of the same species do not have to have the same allelic frequencies