from the world's big
Magic mushrooms evolved to scramble insect brains, send them on wild, scary trips
How psilocybin evolved has more to do with sending insects on terrifying trips than it does making Phish sound good.
- Fungi species that produce psilocybin—the main hallucinogenic ingredient in "magic" mushrooms—aren't closely related to one another.
- Researchers have discovered that the way these fungi independently gained the ability to produce psilocybin is because of horizontal gene transfer.
- Based on how uncommon horizontal gene transfer is in mushroom-producing fungi and the types of fungi that produce psilocybin, it seems likely that the hallucinogenic chemical is meant to scramble the brains of insects competing with fungi for food.
Throughout our history, human beings have demonstrated a powerful and committed love of tinkering with our brain chemistry. We drink the waste of sugar-eating bacteria, smoke the leaves of garden-variety weeds, and munch on mushrooms whose chemicals give us such a strange experience we have to call it magic. We've been doing this for thousands and thousands of years, too: Cave paintings of certain mushroom species suggested that our ancestors liked to turn on, tune in, and drop out as well.
But the very fact that magic mushrooms exist and that their main psychoactive ingredient—psilocybin—can provide such a powerful experience is odd. Nearly all of the qualities of the various species of life on Earth have some kind of functionality. Deer don't have antlers because they're pretty; they're there for mating displays. Cheetahs don't run fast because they're big fans of cardio exercise; its their strategy for catching prey. Magic mushrooms don't produce psilocybin because it makes human beings hallucinate; it's there for a reason.
What makes psilocybin so unusual?
The researchers believe that psilocybin production evolved to disorient insects that would otherwise compete with the fungi for food or consume the fungi themselves.
New research in the journal Evolution Letters has uncovered evidence for the functional purpose of psilocybin in fungi. It's there to screw with insects; specifically, those insects that wouldn't mind chowing down on a fungi's mushroom or on the food that fungi themselves like to eat—dung and wood.
Part of what's made it so difficult to pin down the purpose of psilocybin in mushrooms is that psilocybin-producing mushrooms are mostly not related to one another. It doesn't appear as though a common ancestor developed the ability to produce psilocybin and passed it down to its offspring. Instead, five distinct, distantly related families of fungi make psilocybin.
Psilocybin is a secondary metabolite, meaning it's an organic compound not involved in the growth, development, or reproduction of the fungi itself. Necessarily, its expensive to produce secondary metabolites, and psilocybin in particular is a complicated molecule to make. So, it's extremely weird that it's popped up in disparate species of fungi.
What put the magic in magic mushrooms?
Psilocybe cianescans, one of the psilocybin-producing fungi that the researchers studied.
Photo: Wikimedia Commons
It's unlikely that psilocybin production evolved in distinct mushroom species spontaneously, and since these species aren't related, it's pretty clear that vertical gene transfer—passing down genes from parent to child—is not responsible either. Instead, the researchers surmised that horizontal gene transfer must be the culprit.
Horizontal gene transfer doesn't take up much space in the general public's understanding of evolution. We typically think of evolution as gradual, random changes in the gene that accidentally improve the species' fitness in its environment, which are then passed down to offspring. But genetic material can also be passed between distinct but co-existing species.
While there are a few different mechanisms for horizontal gene transfer, larger critters probably receive genes from other species via transposons, genes that mostly do nothing besides jump around in the DNA and cause problems. Sometimes, transposons take another gene along with them, occasionally getting mixed up with viruses, insects, or other third parties who then deposit the gene into another species.
As an example, the transposon BovB makes up about a quarter of cows' genome, and it's also found in snakes, zebrafish, geckos, and other random species. Rather than there being a branch on the tree of life that traces a distinct line of critters with BovB, instead it looks more like a Jackson Pollock painting—random islands of animals with the BovB gene. Clearly, BovB didn't get to these disparate species by a common ancestor. Instead, it jumped around, hitching rides with third-parties like viruses and insects. Here's a video explainer.
Environment over ancestry
Horizontal gene transfer also appears to be how magic mushrooms got their magic. The interesting part about this is the outsized effect the fungi's environment plays on their evolution. Fungi compete with insects for dung and wood and also are frequently eaten by insects themselves. Producing psilocybin is a great way to scramble the brains of any insect that gets too familiar. Because psilocybin production is so useful to fungi that eat dung and wood, when genes for psilocybin production are randomly inserted in their genome, they thrive, outproducing non-psilocybin-producing fungi.
Psilocybin has recently gained recognition for its ability to treat depression, PTSD, and other mental disorders, which is wonderfully serendipitous for a chemical that started off as an insecticide. In fact, most of the chemicals humans use recreationally or medicinally were made by plants and fungi to ward off insects that would eat them or eat their food. Now, thanks to this research, we have another way to identify what kinds of plants and fungi might hold secret chemicals we can use to improve our lives.
Join us at 2 pm ET tomorrow!
Construction of the $500 billion dollar tech city-state of the future is moving ahead.
- The futuristic megacity Neom is being built in Saudi Arabia.
- The city will be fully automated, leading in health, education and quality of life.
- It will feature an artificial moon, cloud seeding, robotic gladiators and flying taxis.
The Red Sea area where Neom will be built:
Saudi Arabia Plans Futuristic City, "Neom" (Full Promotional Video)<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="c646d528d230c1bf66c75422bc4ccf6f"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/N53DzL3_BHA?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Are we genetically inclined for superstition or just fearful of the truth?
- From secret societies to faked moon landings, one thing that humanity seems to have an endless supply of is conspiracy theories. In this compilation, physicist Michio Kaku, science communicator Bill Nye, psychologist Sarah Rose Cavanagh, skeptic Michael Shermer, and actor and playwright John Cameron Mitchell consider the nature of truth and why some groups believe the things they do.
- "I think there's a gene for superstition, a gene for hearsay, a gene for magic, a gene for magical thinking," argues Kaku. The theoretical physicist says that science goes against "natural thinking," and that the superstition gene persists because, one out of ten times, it actually worked and saved us.
- Other theories shared include the idea of cognitive dissonance, the dangerous power of fear to inhibit critical thinking, and Hollywood's romanticization of conspiracies. Because conspiracy theories are so diverse and multifaceted, combating them has not been an easy task for science.
Coronavirus layoffs are a glimpse into our automated future. We need to build better education opportunities now so Americans can find work in the economy of tomorrow.
- Outplacement is an underperforming $5 billion dollar industry. A new non-profit coalition by SkillUp intends to disrupt it.
- More and more Americans will be laid off in years to come due to automation. Those people need to reorient their career paths and reskill in a way that protects their long-term livelihood.
- SkillUp brings together technology and service providers, education and training providers, hiring employers, worker outreach, and philanthropies to help people land in-demand jobs in high-growth industries.
Source: McKinsey Global Institute analysis [PDF]<p>Work in understanding the skills at the heart of the new digital economy is leading to novel assessments that allow individuals to prove mastery to faithfully represent their abilities—but also to give weight and stackability to the emerging ecosystem of micro-credentials that make education more seamless across time and education providers. And we are seeing the beginnings of a renewal in the liberal arts, focused on building human skills in affordable ways that are accessible to many more individuals and far more effective.</p><p>Amidst these dark times, there is much opportunity to refresh the nation's education and training solutions to support the success of individuals and society writ large.</p>