|By Joseph Scalise | 2 years ago|
Researchers from Ohio State University may have discovered why several different mushroom species evolved as hallucinogens, according to new research published in Evolution Letters.
Psilocybin is a chemical compound that causes humans to hallucinate when they eat certain mushroom species. However, it may cause insects to lose their appetite as well.
The substance is found in over 200 different mushroom species, which is an odd trend for such a specific evolutionary trait. As a result, the group in the study took a closer look at the compound to see if its spread came about through horizontal gene transfer — a process that occurs when genetic material shifts between organisms in a way other than hereditary transfer.
In the study, the group analyzed both psilocybin and non-psilocybin mushrooms. While comparison allowed them to narrow the similarities between psilocybin mushrooms down to five genes, it did not explain why mushrooms from different groups evolved the same trait.
To answer that mystery, the group looked at psilocybin’s properties. They found that, though it causes hallucinations when ingested by humans, it also dampens the appetites of insects. As a result, it is likely a defensive trait that became widespread in regions that are teeming with bugs.
“We speculate that mushrooms evolved to be hallucinogenic because it lowered the chances of the fungi getting eaten by insects,” said lead author Jason Slot, an assistant professor of fungal evolutionary genomics at The Ohio State University, according to Science Alert. “The psilocybin probably doesn’t just poison predators or taste bad. These mushrooms are altering the insects’ ‘mind’ – if they have minds – to meet their own needs.”
Researchers are not sure how the genes moved across species, but its presence in so many different kinds of mushrooms suggest it came about through horizontal transfer. The team plans to follow up on their research to see if they can get a better idea of its exact purpose.
“[O]ur main question is, ‘How did it evolve?’” added Slot, in a statement. “What is the role of psilocybin in nature?”