Wherefore the Magic? The Evolutionary Role of Psilocybin in Nature
Ecology and Evolution April 1, 2026 Kirsty J. Matthews Nicholass, Ilona Flis, Me Hanley et al.
Psilocybin, the psychedelic compound in 'magic' mushrooms, is produced by fungi across eight distantly related genera, but why natural selection favored its biosynthesis is unknown. Exposing Drosophila larvae to extracts from Psilocybe mushrooms reduced survival, pupation rates, and locomotion, and adults that developed from exposed larvae had smaller thorax and wing sizes and subtle asymmetries in wing venation, indicating developmental stress. However, flies lacking the serotonin receptor 5HT2A—which mediates psilocybin's effects in humans—showed the same response as wild-type flies. DNA metabarcoding showed that Psilocybe semilanceata's invertebrate community overlapped with the non-psychedelic fungus Mycena epipterygia, suggesting psilocybin's ecological role remains unclear.