What is a major factor influencing the persistence of allele G in a population?

The persistence of allele G in a population can be significantly influenced by its neutral fitness in heterozygotes. When allele G exhibits neutral fitness in heterozygous individuals, it means that individuals carrying one copy of allele G and one copy of another allele (let's call it allele A) do not have a fitness advantage or disadvantage compared to homozygous individuals (those carrying two copies of the same allele). This neutrality allows allele G to be maintained in the gene pool, as it doesn't face strong selection pressures that would otherwise eliminate it.

In a scenario where alleles have neutral impact on fitness, they are likely to drift and persist over generations simply due to random mating and genetic drift, rather than being selected against or for. This phenomenon is essential in understanding how genetic diversity is retained within populations, especially in fluctuating environmental conditions or when selective pressures vary.

Essentially, the lack of a fitness cost for heterozygotes means that allele G can continue to exist in the population, contributing to genetic diversity and potentially providing adaptive potential in future environmental changes.