Study: Mushrooms became hallucinogenic to keep away insects

Feb. 27 (UPI) — Scientists know what makes magic mushrooms magical, a chemical compound called psilocybin. But researchers have been less clear on how and why mushrooms evolve to produce the psychedelic ingredient. New research offers clues.

What’s so unusual about magic mushrooms is that the species that produce psilocybin aren’t closely related. They trace their roots to divergent lineages and boast unique genomes.

To better understand the relationship between different magic mushrooms, scientists sequenced the genomes of three psychedelic mushrooms species and compared them to the genomes of several of their non-psychedelic relatives. The comparative analysis revealed a group of genes shared by the three magic mushrooms.

Still, the analysis didn’t answer the scientists’ chief question: how and why did psilocybin evolve?

In a search for more answers, scientists looked to the origin of the species’ shared genes. Researchers believe the magic mushrooms share the genetic code for psilocybin production through a process called horizontal gene transfer.

Scientists hypothesized that magic mushrooms shared these genes in an environment rich with fungus-eating insects — an environment such as animal manure and rotting wood.

Psilocybin’s brain-altering abilities don’t just impact humans, they also disrupt the normal neural processes of insects. Research has shown that the compound depresses the appetite of flies.

“We speculate that mushrooms evolved to be hallucinogenic because it lowered the chances of the fungi getting eaten by insects,” Jason Slot, an assistant professor of fungal evolutionary genomics at Ohio State University, said in a news release.

Slot and his colleague published their hypothesis in the journal Evolution Letters.

“The psilocybin probably doesn’t just poison predators or taste bad,” Slot said. “These mushrooms are altering the insects’ ‘mind’ — if they have minds — to meet their own needs.”

Several studies have looked at the potential of psilocybin as treatment for mental health problems like anxiety and depression. Slot and his research partners suggest their work can help scientists better understand theses brain-altering molecules.