Evolution IS the response to the environment and life-affecting issues. Evolution is, in a manner of speaking, random genetic mutations that result in having a better chance of surviving those environmental changes. So, yes, modern medicine is definitely a factor in keeping people from passing on their genes. Take for example, a childhood leukemia victim. If modern medicine saves that child, that child now has the ability to pass on whatever genes predisposed them to that leukemia. Now, I'm not saying that that person shouldn't be saved, but it serves to support both the article and the medicine aspect. Society's support of curing leukemia, combined with the ability to do so, have limited the evolutionary path.