Genetic Drift: Population Size

Try these parameter values:

Small Population

N: 5
m: 1.0E-4

Larger Population

N: 200
m: 1.0E-4

Genetic Drift: Population Size

The rate of fixation of selectively neutral alleles is inversely related to the population size:

The rate of loss is:

Genetic drift occurs because the population size is not infinite, allowing chance events (sampling error) to occur.

Genetic Drift: Population Size

Adjust the population size and the mutation rate to the right:

Initially, each of the 10 genes in this population has only one allele. Mutations introduce a second allele at the mutation rate chosen (m). Because the population size is not infinite, the frequency of the introduced allele fluctuates and may either become fixed or lost. Adjust the population size to see its effect on the amount of genetic drift experienced by the population.