Quote:

The original poster makes a claim that man evolved with psychadelics and it is refuted with the arguement that shrooms won't change your genetics anymore than weighlifting will make your offspring stronger...

---

First of all, the assumption that since mushrooms dont have a direct effect on the user's DNA means that they havent influenced our evolution is asinine, and indicates a profound lack of understanding of the science of evolution. 

Evolution predates DNA.  Or do you think that Darwin was some kind of anachronistic geneticist who used his time-travelin choo-choo train to go back to the 1800's and set up shop? 

Anyway, I think its pretty safe to assume that every aspect of our natural environment has had some effect on our evolution.  And many socio-cultural factors have had evolutionary impacts as well. Being that mushrooms and certain other substances directly effect the brain and nervous system, and that they are aspects of both our natural and social environment, I would say its pretty safe to assume that they meet the qualifications of an evolutionary stressor on the brain.  The impacts of this stressor have not been fully explored, but I do believe they have been mostly positive.