|
Cannabis Campaigners' Guide News Database result:
|
|
Cannabis Did Not Always Produce THC and This Study Shows How Evolution Figured It Out Tibi Puiu ZME Science Friday 31 Jul 2026 Cannabis did not evolve THC with a single, elegant molecular stroke. Instead, the plant appears to have stumbled toward it by “experimenting” chemically, copying useful genes, and slowly refining a messy process into the precise cannabinoid assembly line we recognize today. According to a new study from Wageningen University & Research, the familiar compounds THC (tetrahydrocannabinol), CBD (cannabidiol), and CBC (cannabichrome) emerged from such an evolutionary period of biochemical improvisation. By resurrecting long-extinct enzymes and testing them in the lab, researchers have reconstructed how cannabis acquired the ability to make its signature molecules (including those that can make you high). This is the first experimental evidence for how cannabinoid biosynthesis originated and diversified within the cannabis lineage. The results also hint at something unexpected: the oldest versions of these enzymes may be better suited for modern biotechnology than their highly specialized descendants. When Cannabis Enzymes Did Not Pick Sides In living cannabis plants, cannabinoid production looks tidy. Different enzymes handle different jobs. One mostly produces the precursor to THC. Another focuses on CBD. A third leads to CBC. But evolution rarely starts with tidy systems. The Wageningen team shows that the earliest cannabis-specific enzyme involved in cannabinoid biosynthesis was a generalist. Rather than making a single product, it converted the same starting molecule into several different cannabinoid acids at once. That starting molecule, known as CBGA, is sometimes called the “mother cannabinoid.” Modern enzymes push it down narrow chemical paths. The ancestral enzyme did not. It generated a mixture: THCA, CBDA, and CBCA together. Rebuilding Enzymes from Deep Time To uncover this history, the researchers used ancestral sequence reconstruction, a technique that allows scientists to infer ancient proteins from modern DNA. They compared cannabinoid-related genes from cannabis with those from close relatives such as hops. Using evolutionary models, they predicted what key enzymes must have looked like millions of years ago. Then they synthesized those genes and expressed them in yeast, effectively bringing ancient plant enzymes back to life. This approach let them test not just what the genes looked like, but what they actually did. The results revealed a clear sequence. Enzymes predating cannabis showed no ability to process CBGA. The first enzyme unique to cannabis could process it, but did so broadly, producing multiple cannabinoids. Only after later gene duplications did enzymes emerge that strongly favored THC or CBD pathways. This pattern — generalists first, specialists later — is common in evolution. It gives organisms room to explore chemical possibilities before natural selection locks in the most useful ones. Copying Genes, Inventing Chemistry Gene duplication seems to have been key in the cannabis plant’s journey towards molecular specialization. When a gene duplicates, one copy can maintain its original function. The other gains freedom to mutate. Sometimes that freedom leads nowhere. Sometimes it leads to entirely new chemistry. Cannabis appears to have used this evolutionary trick repeatedly. Duplications of a single ancestral enzyme allowed different copies to drift toward different cannabinoid products. Over time, those copies became increasingly specialized. This challenges earlier assumptions that CBD-like compounds came first. Instead, the ancestral enzyme already produced THC precursors alongside others, suggesting that psychoactive chemistry emerged early — and only later became finely tuned. For the plant, these compounds were unlikely to matter because of their effects on humans. More likely, they played roles in defense, stress response, or microbial resistance. Chemical diversity itself can be an advantage when threats are unpredictable. Ancient Enzymes, Modern Advantages The study’s evolutionary insights come with a practical twist. The resurrected ancestral enzymes turned out to be easier to work with than modern ones. In yeast cells, they expressed more readily and functioned more robustly. “What once seemed evolutionarily ‘unfinished’ turns out to be highly useful,” says Robin van Velzen in a Wageningen University & Research press release. “These ancestral enzymes are more robust and flexible than their descendants, which makes them very attractive starting points for new applications in biotechnology and pharmaceutical research.” This matters because demand for medically relevant cannabinoids keeps rising, while plant-based production remains slow and variable. Biotechnological approaches—such as using microbes instead of crop fields—promise consistency and scale, but enzyme performance often limits progress. Ancient enzymes may offer a shortcut. Rethinking Rare Cannabinoids like CBC One cannabinoid stands out in the study: CBC. CBC has drawn scientific interest for potential anti-inflammatory and pain-related effects, yet it appears only in small amounts in most cannabis plants. According to the researchers, this scarcity stems from enzyme specialization that favored other pathways. “At present, there is no cannabis plant with a naturally high CBC content. Introducing this enzyme into a cannabis plant could therefore lead to innovative medicinal varieties,” van Velzen says. In the lab, the team engineered intermediate enzyme forms that produced CBC with striking specificity. That opens two possible futures: cannabis plants redesigned to favor rare cannabinoids, or microbes engineered to produce them efficiently. What Evolution Still Keeps Hidden Despite the clarity and elegance of the experiments, gaps remain. The researchers note that limited genomic data from hop leaves open the question of whether early cannabinoid activity arose just before or just after cannabis split from its relatives. Evolutionary reconstructions also cannot perfectly capture the order of ancient mutations. Still, the study marks a shift. It moves cannabinoid evolution from speculation to experimental testing. By replaying evolution in the lab, scientists can now see how cannabis chemistry took shape. In this view, THC is not just a cultural artifact or a pharmacological tool. It is the product of evolutionary trial and error, refined over millions of years. And some of the most promising tools for tomorrow may come not from cannabis’s present, but from its deep molecular past. The findings appeared in the Plant Biotechnology Journal. https://www.zmescience.com/science/news-science/cannabis-evolution-of-thc/
After you have finished reading this article you can click here to go back.
|
This page was created by the Cannabis Campaigners' Guide.
Feel free to link to this page!