A certain genetic mutation is found with a high frequency in populations of humans living in places that experienced a deadly disease in the past. This same mutation is rare in places that have no history of the disease. Based on how genes work, this data best supports which of the following explanations? a. The genetic mutation was present in all populations but did not get passed on in places where humans did not contract the disease.
b. This genetic mutation codes for the production of a protein that provides resistance to the disease.
c. The disease causes the genetic material of humans to mutate just before it causes their disease.
d. Humans with this mutation develop this disease and then spread it to other humans without the mutation.

ok

explanation:

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

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