Final answer:
An allele like delta 32 present at 1 percent in a gene pool would have a limited impact but could be affected by genetic drift. Such an allele's frequency could randomly decrease or increase, especially in small or isolated populations.
Step-by-step explanation:
An allele that is present at only 1 percent of the overall gene pool, such as delta 32, would be expected to have limited impact on the population's genetic structure.
The phenomenon that can alter the frequencies of such a rare allele is known as genetic drift, which is essentially the effect of chance events in small populations. As alleles are randomly sampled each generation, rare alleles might be lost or even become more common purely due to chance events like who survives or reproduces.
One example of genetic drift's impact involves a scenario where an allele is rare, such as a disease-causing recessive allele. Even though it might exist in a population, the likelihood of two carriers mating and producing offspring with the disease is low. However, the allele can maintain itself in the population at a low frequency over time unless a specific event, like inbreeding, increases its occurrence.
Likewise, in small populations or isolated environments, like an island, genetic drift can occur more rapidly, potentially causing significant changes in allele frequencies, and even leading to the elimination of alleles from the gene pool.