Final answer:
Genetic drift refers to random changes in allele frequencies from one generation to the next. There is no expectation of an allele frequency remaining the same or changing in a specific direction due to genetic drift. It can lead to fixation or loss of alleles, especially in small populations. The correct option is D.
Step-by-step explanation:
Under the rules of genetic drift, if an allele frequency is 0.60, there are no expectations of the allele frequency in the next generation. Genetic drift is the change in allele frequency from one generation to the next that occurs purely by chance. In terms of allele frequency, it is like tossing a coin.
When you have a small population and you randomly pick who reproduces, the allele frequency may change due to random events rather than due to any particular advantage the allele confers. Genetic drift can eventually lead to the fixation of an allele, where only one allele remains in the population, or to the complete loss of an allele.
For example, if only half the individuals of a species reproduce in one generation, and by chance most of the reproducing alleles are of one type, then in the next generation, the frequency of that allele will increase. This can lead to significant fluctuation in allele frequencies over time, especially in small populations.