Cannabis has been deeply connected to human civilization for generations. People have valued the plant for its functional fibers, medical applications, and recreational uses. Its presence appears in ancient cultures and continues in modern medical and recreational spaces. Marijuana has certainly sparked plenty of interest and disagreement.
Its widespread use continues, yet true cannabis origins remained hidden for centuries. Political rules, legal limitations, and hidden growing practices created gaps in scientific knowledge about the plant’s past. A significant scientific step forward just happened.
A research team uncovered new genetic details. These details explain where Cannabis sativa first grew. Cannabis sativa is a species that includes marijuana and hemp. Science now shows how it split into the kinds we know today. An article in the journal Science Advances details this discovery. It gives a new view on the history of a famous, debated plant.
Looking at Cannabis Genes to Find Answers
Scientists examined 110 different cannabis genomes collected from across the globe. Advanced DNA sequencing technologies helped create a clearer picture. People now understand better how Cannabis sativa changed and branched out over time. A deep molecular look illuminated a long-missing chapter of the plant’s story.
Researchers built phylogenetic trees by analyzing DNA sequences. These trees are similar to genetic family trees and outline how different cannabis lines relate. Genetic maps revealed a structured development into four separate cannabis groups. Most importantly, they identified a base group called “basal cannabis.” Earlier research efforts had missed this group entirely.
Discovering the Oldest Known Cannabis Relative
Researchers made a remarkable finding identifying basal cannabis. People describe it as a sister group to all other cannabis types. Basal cannabis stands genetically apart from modern farmed hemp and psychoactive marijuana. Wild strains and landrace varieties belong to this group. Landrace varieties are local strains that people have traditionally bred. You can still find these types in parts of China today.
Basal cannabis possesses distinct genetics, which suggest it may most closely resemble ancient, wild cannabis plants. These plants existed before humans started shaping the species through breeding choices.
Dr. Luca Fumagalli, a conservation biologist at the University of Lausanne, contributed to the study. He pointed out that cannabis is one of the earliest plants that humans have cultivated. However, its scientific exploration has lagged. Ongoing social and political challenges have led to these setbacks. “Few crops have been as steeped in controversy as Cannabis sativa,” he remarked.
Meet the Four Main Cannabis Groups
Scientists sorted cannabis into four main genetic groups. Each group offers a look into a different part of its development:
- Basal Cannabis: This is the ancestral group. It includes wild cannabis and landrace types mainly found in China. These plants share genetic markers absent in modern farmed strains. Their existence points toward East Asia as the likely place where early domesticated cannabis originated.
- Hemp: Hemp makes up another group. It contains non-psychoactive cannabis types that farmers grow mostly for fibers, seeds, and oils. Historically, hemp has been critical in making textiles and other goods, especially across Europe and North America. A low amount of THC separates it from drug-type cannabis. THC is the compound causing the plant’s mind-altering effects.
- First Drug-Type Cannabis Group: People find both wild and farmed psychoactive cannabis varieties in this group. They mainly started in South and Central Asia. Locations include modern-day China, India, and Pakistan.
- Second Drug-Type Cannabis Group: Cultivated drug cannabis strains fit into this category. Farmers grow these strains all over the world. You see them particularly in places where marijuana use is culturally accepted or medically common.
The Genetic Basis for THC and CBD Production
The groundbreaking research into cannabis genetics reveals fascinating insights about how selective breeding has altered cannabinoid production pathways over thousands of years. When examining the DNA of various cannabis samples, scientists observed significant differences in genes controlling the synthesis of THC and CBD, the two most prominent cannabinoids.
These genetic analyses help explain how human cultivation practices led to the development of distinct cannabis varieties. During domestication, specific genes associated with cannabinoid production underwent mutations or were selectively lost depending on the desired traits. For hemp varieties, genes favoring fiber production were enhanced while THC production was minimized. Conversely, in drug-type cannabis, genes responsible for psychoactive compounds were strengthened.
Perhaps most interesting is how the study identified specific genetic markers showing that the legal distinction between hemp and marijuana may be more complex than previously believed.
Finding the Original Home and First Farms
Comparing genetics showed that cultivated cannabis started in East Asia, overturning earlier ideas that it began in Central Asia. Researchers also determined when basal cannabis and cultivated cannabis diverged. A divergence occurred nearly 12,000 years ago, which lines up with the dawn of agriculture during the early Neolithic period.
The separation of cannabis into fiber-producing hemp and psychoactive marijuana seems to have happened around 4,000 years ago. Archaeological records support this timeframe. Records show hemp-based fiber objects appeared in East Asia during the Bronze Age. People cultivated cannabis, and then it spread westward, eventually reaching Europe and later other parts of the world.
Farming Changed Cannabis Forever
Some propose that cannabis did not initially have a single purpose when farming began. It likely served as a multi-use crop for thousands of years. People used it for fiber, food, medicine, and perhaps spiritual or recreational activities. Specialized hemp and marijuana varieties came much later. Farmers started selectively breeding plants for distinct features only then.
When people farmed more intensely, the plant’s genetics changed significantly. Specific genes connected to making cannabinoids or fiber strength have mutated. Sometimes, genes disappeared based entirely on the traits farmers wanted. An irreversible split resulted. People valued hemp for its strength and usefulness, while people prized marijuana for its psychoactive and potentially helpful effects.
Long-term genetic modification has had a downside. Researchers believe the original wild ancestors of Cannabis sativa might be extinct today. Cultivated strains possibly replaced or absorbed them completely. Humanity, in effect, genetically re-engineered the species over millennia.
How Cannabis Spread Across the Globe
The movement of cannabis around the world did not happen evenly. Research suggests psychoactive cannabis types moved from East Asia into India roughly 3,000 years ago. Strains reached Africa and Latin America within the past thousand years. North America’s experience with the plant came much later.
European settlers introduced hemp to colonial North America during the 1600s. Settlers initially grew it there for rope and textiles. Chinese cannabis varieties started replacing older European hemp strains by the mid-1800s. Marijuana, with its psychoactive effects, only began making a clear appearance in North American society early in the 20th century. Global movement has further diversified cannabis genes. Such mixing led to many strains varying in looks, effects, and chemical composition.
Perhaps Hemp and Marijuana Are More Alike Than We Think?
The findings from the study also influence perspectives on the definitions of cannabis. Present regulations typically categorize cannabis plants into two categories: hemp and marijuana. Hemp is legally defined as having very low levels of THC, while marijuana contains higher levels. Genetic research suggests that this straightforward classification may reflect a social consensus rather than a scientific distinction.
Researchers identified distinct differences in the DNA of the samples examined. Variations were noted in the genes responsible for the production of THC and CBD. CBD, or cannabidiol, is another significant compound found in the plant. Individuals seek CBD for its potential beneficial effects without the psychoactive effects associated with THC.
Interestingly, five samples that were legally classified as hemp exhibited unexpected genetic characteristics. The findings blurred the distinct boundaries between what is legally defined as hemp and marijuana. This lack of clarity raises essential questions. It may be necessary for people to rethink how cannabis is categorized and regulated in the future. Study authors noted: “From both a biological and functional perspective, the current binary categorization of cannabis as either ‘hemp’ or ‘marijuana’ is brought into question.”
Source:
- Crocq, M. (2020). History of cannabis and the endocannabinoid system. Dialogues in Clinical Neuroscience, 22(3), 223–228. https://doi.org/10.31887/dcns.2020.22.3/mcrocq
