Because the psilocybin mushroom species have similar lifestyles within the ecosystem – they all grow in damp soil and feed by decomposing either dead wood or dung – an adaptation acquired in one species would be helpful to the rest. And given that the ability to synthesize psilocybin has popped up in hundreds of species and persisted for millennia, it must be a real boon to mushroom survival.
“We speculate that mushrooms evolved to be hallucinogenic because it lowered the chances of the fungi getting eaten by insects,” said lead author Dr Jason Slot in a statement.
Organisms that are at risk of being eaten often adapt chemical defense molecules, called secondary metabolites, that make them poisonous or unpalatable. But instead of killing or repelling their would-be predators as plants do, “these mushrooms are altering the insects’ ‘mind’ – if they have minds – to meet their own needs,” said Dr Slot.
What an insect experiences during a mushroom trip is definitely a subject for another day, but one known side effect is a reduction in appetite. Unfortunately for mushrooms, the same deterrent did not work too well for humans. Despite the risk of extreme nausea, people have been seeking out magic mushrooms for least 3,500 years.