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Allele Frequency Equation:
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Allele frequency is the relative frequency of an allele at a particular locus in a population. It shows how common an allele is in a population and is fundamental to population genetics and evolutionary biology.
The calculator uses the allele frequency equation:
Where:
Explanation: The equation counts all copies of the allele in the population (2 from each homozygous individual and 1 from each heterozygous individual) divided by the total number of gene copies (2 per individual).
Details: Allele frequencies are crucial for understanding genetic variation, studying evolutionary processes, assessing genetic risk factors, and conservation genetics.
Tips: Enter the count of homozygous dominant individuals (AA), heterozygous individuals (Aa), and total population size (N). All values must be non-negative integers with N > 0.
Q1: What does an allele frequency of 0.5 mean?
A: An AF of 0.5 means that 50% of all alleles at that locus in the population are the specific allele being measured.
Q2: How is this different from genotype frequency?
A: Genotype frequency refers to the proportion of individuals with a specific genotype, while allele frequency refers to the proportion of a specific allele among all alleles at that locus.
Q3: What's the range of possible allele frequencies?
A: Allele frequencies range from 0 (allele not present) to 1 (allele is the only variant at that locus in the population).
Q4: When would allele frequency be exactly 0 or 1?
A: Frequency of 0 means the allele is not present in the population. Frequency of 1 means all individuals have the same allele (fixed in the population).
Q5: How large should my sample size be?
A: Larger samples give more accurate estimates. For rare alleles, you may need hundreds or thousands of individuals to get reliable frequency estimates.