forkbender, for mckenna's theory to be fully true, it is a long shot. let's suppose that all european natives are not allergic. did the mushrooms grew here ?
what about africa ? let's not forget that all the apes were not just all gathered under a tree. they were really scatered around the globe. what dates does mckenna point out ? do psilocybin mushrooms grow in indonesia, for example ? if they don't grow there (just an hipothesis, i am not sure of the fact and could be anywhere else), the apes have no chance to consume them, and therefore, they have been selected naturally.
did psilocybin affected them as much as it does to us ?
it is a very difficult thing to prove, even with numbers. other fields of interest, for example, linguistics, say that the improvement between homo sapiens and sapiens sapiens was caused by the need of language, and that only, could revolucionize our apes. ufologists say that was a monolith (and kubrickists too :wink: ). i think we should look at mckenna's theory like OUR view of that time. because it is interesting to us, as their theories are to them. we, as self-entitled psychonauts, some times use psychedelics, because they are shortcuts between worlds, and we have all the interest that this thing that we discovered was also used by our most remote ancestors. because we doing it against the society tabus, because it is forbidden, and it is a thing that it is most cherished by those who really understand it. this is our way of showing everyone that we are on the right track, and they were the ones who have been wrong all the time.
that's my view of it. mckenna, as a very bright person, and all of his ideas very supported and brightly argumentated, had his share of crazyness and weirdness (i am remembering timewave zero, for instance). just because he said so, doesn't make it true.