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.

http://www.google.com/search?as_q=&hl=en&num=10&btnG=Google+Search&as_epq=Genetic+drift+&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=&as_qdr=all&as_nlo=&as_nhi=&as_occt=title&as_dt=i&as_sitesearch=.edu&as_rights=&safe=images

Since this is not my area of expertise, I searched Google under the key words "genetic drift" to get these possible sources:

http://en.wikipedia.org/wiki/Genetic_drift
http://www.talkorigins.org/faqs/genetic-drift.html
http://evolution.berkeley.edu/evosite/evo101/IIIDGeneticdrift.shtml
http://www.britannica.com/eb/article-9036394/genetic-drift

To get future answers more quickly (using the appropriate key words), you can conduct your own searches.

I hope this helps. Thanks for asking.

The correct answer is c. Genetic drift results in a change in gene frequencies because the population size is so small that chance occurrences can alter gene frequencies. Genetic drift refers to the random fluctuations in gene frequencies in a population and is caused by chance events. In small populations, these chance occurrences can have a significant impact on the gene pool and lead to changes in gene frequencies. This is because random sampling may result in the loss or fixation of certain alleles, which can alter the genetic composition of the population over time. The other options listed as possible answers do not accurately describe the mechanism of genetic drift.