Convergent biosynthesis of psilocybin in an ectomycorrhizal lineage: is the psychoactive end-product the selected trait?
Mellica Askari, Varun Surapaneni
EcoEvoRxiv July 1, 2026 preprint DOI: 10.32942/x2fd49 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Theoretical or philosophical paper |
|---|---|
| Topics | Psilocybin |
| Key points | Argues that the fungivore-deterrence hypothesis for psilocybin's evolution lacks direct experimental support, and proposes instead that selection acted mainly on the injury-triggered polymerized indoloquinoid end-state of the blueing reaction, with psilocybin serving as its stable storage precursor and vertebrate 5-HT2A psychoactivity being plausibly incidental. The authors outline a five-tier comparative experimental program to adjudicate among these alternatives. |
Abstract
The fungivore-deterrence hypothesis, that psilocybin evolved as a chemical defence against arthropod fungivores via 5-HT receptor agonism, has become the working consensus in fungal chemical ecology, despite resting on a phylogenomic pattern of horizontal gene transfer among saprotrophs and remarkably little direct experimental evidence. Recent biochemistry shows that the ectomycorrhizal Inocybe corydalina assembles psilocybin through a convergently evolved, non-homologous ips cluster whose branched pathway yields baeocystin, not psilocybin, as the primary end-product. We argue that psilocybin's psychoactivity at vertebrate 5-HT2A receptors is plausibly incidental, with selection most likely acting on the injury-triggered polymerized indoloquinoid end-state of the blueing reaction (with psilocybin functioning as its stable storage precursor) and only secondarily on the monomeric congeners baeocystin or aeruginascin. We propose a five-tier comparative experimental program to adjudicate among these alternatives.
Comparable studies
Other theoretical and historical papers on psilocybin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics | 2019 | Theoretical or philosophical paper | |
| Psychedelics as Medicines: An Emerging New Paradigm General population | 2016 | Theoretical or philosophical paper | |
| Theorizing that Psychedelic Assisted Therapy May Play a Role in the Treatment of Trauma-Induced Personality Disorders. | 2024 | Theoretical or philosophical paper | |
| What Geometric Visual Hallucinations Tell Us about the Visual Cortex | 2002 | Theoretical or philosophical paper | |
| Psilocybin-assisted therapy of major depressive disorder using Acceptance and Commitment Therapy as a therapeutic frame | 2020 | Theoretical or philosophical paper |