This research reveals how hallucinogenic mushrooms acquired and shared the genetic ability to produce psilocybin through horizontal gene transfer between species. The findings show that mushrooms likely evolved this capability as an ecological adaptation, possibly to influence insects and other organisms in their environment. This has implications for both understanding evolution and developing new therapeutic compounds. Key impacts on everyday life: – Provides new understanding of how natural psychedelic compounds evolved – Suggests new ways to discover novel pharmaceutical compounds from fungi – Helps explain the ecological roles of mushrooms in nature – Advances knowledge for potential therapeutic applications of psilocybin – Demonstrates how organisms can share beneficial genetic traits