“Magic” mushrooms seem to have passed their genes for mind-altering substances around among distant species as a survival mechanism: By making fungus-eating insects “trip,” the bugs become less hungry — and less likely to feast on mushrooms.
The researchers studied a group of mushrooms that all produce psilocybin — the chemical agent that causes altered states of consciousness in human beings — but aren’t closely related. The scientists found that the clusters of genes that caused the ‘shrooms to fill themselves with psilocybin were very similar to one another, more similar even than clusters of genes found in closely related species of mushrooms.
HGT isn’t really one process, as the biologist Alita Burmeister explained in the journal Evolution, Medicine and Public Health in 2015. Instead, it’s the term for a group of more or less well-understood processes — like viruses picking up genes from one species and dropping them in another — that can cause groups of genes to jump between species.
The researchers suggested — but didn’t claim to prove — that the crisis in this case was droves of insects feasting on the defenseless mushrooms. Most of the species the scientists studied grew on animal dung and rotting wood — insect-rich environments (and environments full of opportunities to perform HGT). Psilocybin, the scientists wrote, might suppress insects’ appetites or otherwise induce the bugs to stop munching quite so much mush’.