Studying natural selection in the field can be challenging list three possible challenges

List at least three possible challenges Darwin might have faced. Traits other than beak type might affect natural selection. It could take many generations to observe adaptions to a population. The environment may be complex and hard to study

i tried the eyeshadow trick you told me about and it worked so good i i did a yellow going into orange colors and it was bright and you could see it on my eyes

"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."