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