Which statement best describes the outcome of genetic drift?

Genetic drift is a process that occurs when allele frequencies in a population change due to random sampling of organisms, particularly in smaller populations. This randomness can lead to significant shifts in allele frequencies, thereby affecting genetic variation. In small populations, the impact of genetic drift is more pronounced because random events can lead to the loss of alleles (sometimes beneficial ones) entirely from the gene pool. Over time, this can result in decreased genetic variation, making the population less adaptable to environmental changes and more susceptible to extinction.

The other statements do not accurately capture the nature of genetic drift. For instance, it is not a non-random process favoring the strongest alleles, as it operates randomly without regard to the alleles' adaptive value. Genetic drift does not guarantee any positive adaptations for the species, as it may lead to the fixation of harmful alleles instead. Similarly, it does not preserve genetic traits across generations; rather, it can result in the loss of genetic traits as allele frequencies change randomly. Thus, the second statement accurately reflects the consequence of genetic drift in biological populations.