I am praying to god you are not a doctor!!!

First of all evelution cant happen to an indervitual, it's a population of inderviduals that slowly evolves due to mutations in there genctic make up.

And as for your other point, when you get a desease you immune system kicks in and your memory cells grip onto the pathogen and copy the protine sequence on the suface of it and make antibodies to combat it, even when the desease is gone your body still has those antibodies in it so if the desease comes back they attack and destroy it right away and u dont feel a thing.
Now lungs work nothing like that at all, they dont have a memory and so cant develop a tolorance.
MullManiac Reviewed by MullManiac on . Pot not a major cancer risk NEW YORK (Reuters Health) - Although both marijuana and tobacco smoke are packed with cancer-causing chemicals, other qualities of marijuana seem to keep it from promoting lung cancer, according to a new report. The difference rests in the often opposing actions of the nicotine in tobacco and the active ingredient, THC, in marijuana, says Dr. Robert Melamede of the University of Colorado in Colorado Springs. He reviewed the scientific evidence supporting this contention in a recent Rating: 5