How might genetic drift be important in a small population. see section 23.4 (page 470) . view available hint(s) how might genetic drift be important in a small population. see section 23.4 (page 470) . it decreases genetic diversity only by reducing population size. it increases genetic diversity by introducing alleles from one population into another. it decreases genetic diversity via sampling error during mating. it increases genetic diversity by introducing new genes into the dna of a species?

The correct answer is it decreases genetic diversity only by reducing population size.  

The great explanation for this is a bottleneck effect, which is an extreme example of genetic drift. The bottleneck effect occurs when the size of a population is reduced due to a catastrophe. When it happens, only a small, random number of individuals survive the event and pass through the bottleneck. Thus, the genetic composition of the random survivors is now the genetic composition of the entire population which means that the genetic diversity is reduced.