The benefits of artificial selection is that you've taken the traits that you desire from a plant or an animal that could benefit your own survival. (Much like our ancestors bred the highest/most efficient crops, leaving us in a good farming position today). However, the drawbacks of artificial selection is that you effectively destroy any natural selection or "survival of the fittest" thus reducing the gene pool. If a virus or bacteria was effective against a crop that we bred, it would destroy our entire farming industry (also works with animals that we breed).