Final answer:
Allele frequencies may fluctuate due to genetic drift, which is a random change in allele frequencies occurring in a population, especially in small populations. These changes can result in the increase, decrease, or stabilization of allele frequencies, potentially leading to the fixation of an allele over time.
Step-by-step explanation:
Genetic drift is a random change in allele frequencies within a population, which can cause these allele frequencies to fluctuate over time. This variation occurs due to chance events that affect which individuals survive to reproduce and pass on their genetic material. For example, if by chance, one organism with a particular allele is more successful in reproducing than others, the frequency of that allele may increase in the population. However, these changes are not necessarily stable or directional; allele frequencies can also decrease or simply change without fixation.
In small populations, genetic drift tends to have a more pronounced effect because each individual's genetic contribution represents a larger portion of the genetic makeup of the next generation. Over time, this can lead to the random increase or decrease of allele frequencies. The process can eventually result in the fixation of an allele within the population, where only a single allele remains and genetic variation is lost. This process of genetic drift is like a random walk, where allele frequencies fluctuate until they potentially reach fixation.
Therefore, answering the question, 'do allele frequencies go up overtime after genetic drift?', the answer is not absolute. Allele frequencies may go up, go down, or remain the same due to genetic drift, depending on random sampling and events in each generation. The change is spontaneous and does not consistently result in the increase of allele frequencies over time.