In population genetics, what does "allele frequency" refer to?

Allele frequency refers to the proportion of a specific allele among all alleles for a particular gene in a population. It provides insight into the genetic diversity of that population and how common or rare a particular variant of a gene is compared to others present in that gene pool. High allele frequency suggests that the allele is prevalent, while low allele frequency indicates that it is less common. Understanding allele frequencies is crucial for studying evolution, as changes in these frequencies can suggest shifts in population dynamics, selective pressures, or genetic drift.

In contrast, the total number of alleles in a population does not provide meaningful information about genetic variation without considering how many of each allele are present, making the concept of frequency more useful. The notion of the most common genetic traits relates to phenotypic traits rather than directly addressing genetic variation at the level of alleles. Lastly, the occurrence of mutations is an important aspect of genetic diversity, but it doesn't define allele frequency, which specifically concerns the existing alleles rather than new mutations arising in a generation.