Actually, cloning has NOT allowed us to weed out anything as the clone is a copy of the original, warts and all.
(Start by researching your topic)
There are a lot of things both positive and negative about selection.
I will not write your paper for you (didn't think we would did you?) but the arguments can now be made both ways based on the recent history of the last 60 years.
For example, you can start your paper with corn. It started as a small grass and was cultivated and bread to be the primary foodstuff of the New Wolrd. This would be a positive "design." On the other hand, you can point out that breading of dogs has lead to problems. The German Shepard has poor hips. the bulldog has trouble breathing, all the result of breading for one trait without realizing what else could happen.
Then you have the sociological examples in the world today. China's "One Child" policy lead to the killing of many female children leading to a social imbalance. As China became more industrialized and women became more independent, this increased the problem of not enough women to go around. The enhancing of "desirable traits" often comes with unknown consequences. "Life," to use the quote, "finds a way."