Final answer:
If rare beneficial alleles are lost due to genetic drift or inbreeding, it can lead to a decrease in fitness and genetic variation in the population.
Step-by-step explanation:
The allele frequencies of a population can change through various mechanisms, such as natural selection, genetic drift, and inbreeding. If rare alleles that are beneficial to individuals are lost due to drift or inbreeding, it means that the population may experience a decrease in fitness. This can lead to a reduction in the overall genetic variation of the population and an increased risk of negative genetic effects.