What do you think of the 'Stoned Ape' theory of evolution?

I do think that psilocybins, and psychoactive mushrooms had an impact on our evolution to some extent, but I do not possess the biological knowledge to know or support Mckenna's extensive claims. After all, Mckenna was a heavy addict of hallucinogens, and his love for the effects of them could have lead him to justify his usage by theorizing in this sort of way you have pasted here.