I'm an atheist, but I believe we we're created by alien beings, which you can call God. I bthink they probably whent through alot of trial and error to come up with who we are. But because nothing is perfect, adnomalities in our genes and just over time and being subjected to pollutent, natural or otherwize, we have deloped diseases. The only way to stop diseases like cancer, or MD is through minipulation of our genes. Find the gene or genes that are bad and repair them and alot of diseases could be cured. To wipe the disease out you would have to take the 2 people making a baby and test their genes (DNA) to find the genes in question and if the combination of 2 DNA's would or could cause a disease causing cell to form.
Pollution is a big cause of sickness and disease. We will probably never, totally get rid of pollution. Either from our foods, the water or the air. Just like in foods, like vegetables and or fruit, scientists are constantly coming up with ways to genetially make things disease resistant. Unfortunatley, they don't check enough to make sure people are disease resistant to the genetic modification. As long as it is a "ACCETABLE" low number of people that are allergic to or intollerable to the genetic fix it's allowed. What happens over time though. Constant consumption of the genetically change product, changes or mutates our DNA and we pass in down to our children and childrens, children.
Yes, we are constantly evolving as a species, but not always for the good. When ever you artificially change a product that is absorbed by the human body, you artificially change the human.