Topic 14 Terms

population

A group of individuals of the same species that interbreed or have the potential to interbreed, forming a shared gene pool.

phenotype frequency

The proportion of individuals in a population that display a particular observable trait or phenotype.

genotype frequency

The proportion of individuals in a population that possess a specific genotype for a given gene.

allele frequency

The fraction of all copies of a gene in a population that are of a particular allele; reflects how common an allele is within the gene pool.

allele counting method

A method to calculate allele frequency by counting the total number of copies of each allele in a population and dividing by the total number of gene copies.

Hardy-Weinberg equilibrium

A theoretical state in which allele and genotype frequencies remain constant from generation to generation, assuming no evolutionary influences.

Hardy-Weinberg equation

A mathematical relationship describing genotype frequencies from allele frequencies in a non-evolving population: p² + 2pq + q² = 1.

population size

The number of individuals in a population; large populations minimize random changes in allele frequency due to genetic drift.

random mating

A condition in which individuals pair by chance and not according to their genotypes or phenotypes, ensuring alleles combine randomly.

selection

A process where certain genotypes confer a reproductive or survival advantage, causing allele frequencies to change over generations.

migration

The movement of individuals (and their alleles) between populations, which can introduce new alleles or alter allele frequencies.

mutation

A change in DNA sequence that can introduce new alleles into a population and potentially alter allele frequencies over time.