Final answer:
The time to fixation of a neutral allele is directly proportional to the population size of the species.
Step-by-step explanation:
The time to fixation of a neutral allele is directly proportional to the population size of the species. This is because genetic drift, which is the random change in allele frequencies, has a larger impact on small populations. In small populations, genetic drift can cause alleles to be lost or fixed more quickly due to chance events. As a result, the time to fixation of a neutral allele is shorter in small populations compared to large populations.