posted by Harry .
Genetic drift results in a change in gene frequencies because
a. gene flow within the population is less than gene flow between populations.
b. reproduction is non-random within the population
c. the population size is so small that chance occurrences can alter gene frequencies.
d. the population has not yet stabilized.
e. the population is so large that natural selection has little noticable effect.
Since this is not my area of expertise, I searched Google under the key words "genetic drift" to get these possible sources:
To get future answers more quickly (using the appropriate key words), you can conduct your own searches.
I hope this helps. Thanks for asking.