For decades, the names THC, CBD, and CBC have floated through public conversation as if they were fixed, timeless features of the cannabis plant. They are discussed as chemical signatures, as medicinal possibilities, as cultural symbols. Yet a quieter and more fundamental question has lingered beneath all of this attention: where did these compounds actually come from? Not in a chemical sense, but in an evolutionary one. How did a plant come to possess the molecular tools needed to make them at all?
Researchers at Wageningen University & Research have now offered an answer grounded not in speculation, but in experiment. By reaching back millions of years into the evolutionary past of cannabis, they have shown how the plant gradually acquired the ability to produce its most famous cannabinoids. In doing so, they have also uncovered enzymes that may reshape how these compounds are made for medicinal use.
Rewinding Evolution in the Laboratory
The work, published online on 26 December in the Plant Biotechnology Journal, did something remarkable. Instead of studying only the cannabis plants that exist today, the researchers reconstructed enzymes that no longer exist in nature. These enzymes were active in ancient ancestors of cannabis, long before modern varieties appeared. In today’s plants, enzymes are central players in cannabinoid production, driving the chemical reactions that yield compounds such as THC, CBD, and CBC. The new study asks what those enzymatic players looked like before evolution refined them into their modern forms.
To answer this, the researchers used a method called ancestral sequence reconstruction. By comparing DNA from modern plants, they inferred the genetic sequences of enzymes that existed millions of years ago. These were not theoretical models left on a computer screen. The inferred enzymes were physically recreated in the laboratory and then tested to see what they could actually do.
This approach allowed the team to move beyond inference and into demonstration. It provided the first experimental evidence showing that the biosynthesis of cannabinoids such as THC originated within a relatively recent ancestor of cannabis, and that this biochemical ability became increasingly precise over evolutionary time.
When One Enzyme Did Many Jobs
In modern cannabis plants, cannabinoid production is highly specialized. Different enzymes are responsible for producing THC, CBD, and CBC, each tailored to generate a specific compound. The study reveals that this precision was not always present. The ancestral enzyme from which these modern enzymes descended was far less picky.
This ancient enzyme was a generalist. Rather than producing a single cannabinoid, it could generate several at the same time. The researchers showed that only after gene duplications occurred during cannabis evolution did distinct enzymes emerge. Each duplicated gene followed its own evolutionary path, gradually becoming specialized for the production of a particular compound.
This evolutionary story transforms the way cannabinoid biosynthesis is understood. What now appears as a finely tuned chemical assembly line began as a more flexible system, capable of producing multiple outcomes from the same molecular machinery. Over time, natural selection sculpted this flexibility into specificity.
Bringing Extinct Molecules Back to Life
Reconstructing ancestral enzymes is one thing; proving their function is another. The Wageningen researchers did not stop at genetic reconstruction. They expressed these ancient enzymes in the laboratory and observed their activity directly. In doing so, they effectively brought extinct molecular machines back to life.
The experiments revealed how cannabinoid biosynthesis evolved step by step. The ancestral enzymes could catalyze reactions leading to multiple cannabinoids, while later versions became increasingly refined. This gradual sharpening of function provides a rare experimental glimpse into evolutionary processes that are usually inferred only indirectly.
The findings also underscore the power of fundamental research into plant DNA. By understanding how genes and enzymes evolved, scientists can uncover not only the history of a plant, but also new possibilities for its future use.
Unexpected Strength in Evolutionary Imperfection
One of the most striking outcomes of the study was not just historical insight, but practical potential. The reconstructed ancestral enzymes turned out to be easier to produce in microorganisms, such as yeast cells, than their modern counterparts. This matters because cannabinoids are increasingly produced using biotechnological approaches rather than extracted directly from plants.
The reason lies in the nature of these ancient enzymes. They are more robust and flexible than the specialized enzymes found in modern cannabis. What might once have seemed like evolutionary incompleteness now appears as an advantage.
“What once seemed evolutionarily ‘unfinished’ turns out to be highly useful,” says WUR researcher Robin van Velzen, who conducted the study together with his colleague Cloé Villard. “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.”
In this light, evolution’s early experiments become tools for modern science. The very features that were later refined away may now offer solutions to technical challenges in cannabinoid production.
A Glimpse of New Medicinal Paths
Among the reconstructed enzymes, one in particular stands out. This enzyme represents an evolutionary intermediate and produces CBC very specifically. CBC is a cannabinoid that has drawn interest for its anti-inflammatory and analgesic properties. Yet in nature, it remains elusive in high concentrations.
“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,” says Van Velzen.
This observation highlights a bridge between evolutionary biology and applied science. By identifying and using enzymes that no longer exist in modern plants, researchers may be able to create new varieties or production systems that nature itself never completed.
Why This Discovery Matters
This research matters because it reshapes understanding on multiple levels at once. At the most fundamental level, it provides experimental evidence for how complex plant chemicals evolve. Cannabinoids did not appear fully formed; they emerged through a series of evolutionary steps, driven by gene duplication and gradual specialization of enzymes.
At a practical level, the work opens new doors for biotechnology. The ancestral enzymes described in the study are not just historical curiosities. Their robustness and flexibility make them promising tools for producing cannabinoids in microorganisms, a method that is increasingly important for medicinal applications.
Finally, the study offers a reminder that evolution does not always move toward immediate perfection. Traits that appear crude or unfinished in hindsight can carry hidden strengths. By revisiting these early forms, science can uncover opportunities that were lost along the path to specialization.
In tracing the origins of THC, CBD, and CBC back to their ancient enzymatic roots, the researchers have shown that the past of the cannabis plant is not merely a story of where it came from. It is also a map of where cannabinoid science might go next.
More information: Cloé Villard et al, Resurrected Ancestral Cannabis Enzymes Unveil the Origin and Functional Evolution of Cannabinoid Synthases, Plant Biotechnology Journal (2025). DOI: 10.1111/pbi.70475
