In his book Food of the Gods, Terrence McKenna proposed that the transformation from humans' early ancestors Homo erectus to the species Homo sapiens mainly had to do with the addition of the mushroom Psilocybe cubensis in its diet - an event which according to his theory took place in about 100,000 BC (this is when he believed that the species diverged from the Homo genus). He based his theory on the main effects, or alleged effects, produced by the mushroom. One of the effects that comes about from the ingestion of low doses, which agrees with one of scientist Roland Fischer's findings from the late 60s-early 70s,[23] is it significantly improves the visual acuity of humans - so theoretically, of other human-like mammals too. According to McKenna, this effect would have definitely prove to be of evolutionary advantage to humans' omnivorous hunter-gatherer ancestors that would have stumbled upon it "accidentally"; as it would make it easier for them to hunt.

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This is a clip from Duncan Trussell's Comedy Central Pilot "Thunderbrain."http://www.youtube.com/user/duncantrussell