Final answer:
Small populations are more susceptible to genetic drift, resulting in a loss of genetic diversity over time. On the other hand, large populations have a larger gene pool and are buffered against these effects.
Step-by-step explanation:
In biology, small populations are more susceptible to the forces of genetic drift. When there is a small population size, there is less genetic variation and a higher likelihood of losing alleles due to random chance events. On the other hand, large populations have a larger gene pool and are buffered against the effects of chance. For example, if one individual in a population of 10 dies before reproducing, 10% of the gene pool will be lost. However, in a population of 100, only 1% of the gene pool will be lost, which is less impactful on the population's genetic structure.