For those not interested in reading the links, it appears that they posit a theory of linguistic evolution that was dependent on psilocybin-containing mushrooms. From one of those articles, In addition, because McKenna (who describes himself as "an explorer, not a scientist") is also a proponent of much wilder suppositions, such as his "Timewave Zero" theory, his more reasonable theories are usually disregarded by the very scientists whose informed criticism is crucial for their development. Probably not notable enough to merit inclusion, and the sources certainly aren't reliable enough.