The evolutionary divergence between hemp and psychoactive cannabis, commonly referred to as "weed," is a complex subject with limited direct historical records. Cannabis sativa, the plant species encompassing both hemp and psychoactive cannabis, has been cultivated for various purposes for thousands of years.
The split between hemp and psychoactive cannabis primarily arises from human cultivation practices, selecting and breeding for specific traits over time.
Early Cultivation: Cannabis was initially cultivated for its fibers, seeds, and medicinal properties. Ancient civilizations used cannabis for textiles, ropes, food, and medicinal purposes, with historical records dating back thousands of years.
Cultural Selection: Human cultivation practices likely led to the differentiation between plants cultivated for industrial uses (hemp) and those grown for psychoactive compounds (cannabis).
Selective Breeding: Over centuries, different populations and cultures selectively bred cannabis plants based on desired traits. Hemp varieties were cultivated for their tall stature, strong fibers, and low levels of psychoactive compounds (like THC), while cannabis strains with higher THC content were cultivated for their psychoactive effects.
Cultural and Legal Influences: Historical and cultural factors, including the regulation of psychoactive cannabis due to its mind-altering properties, also contributed to the divergence between hemp and psychoactive strains.
While there isn't a precise historical moment when the split between hemp and psychoactive cannabis occurred, it's understood that human selection and cultivation practices over millennia led to distinct varieties optimized for specific purposes. In recent decades, scientific advancements in genetics have shed light on the genetic differences between hemp and psychoactive cannabis, aiding in our understanding of their evolutionary divergence.
Today, legal definitions often distinguish hemp based on its THC content (0.3% or lower in the United States), while psychoactive cannabis typically contains higher levels of THC, resulting in the differentiation between the two for legal and agricultural purposes.
The historical divergence between hemp and psychoactive cannabis represents the outcome of human cultivation practices and selective breeding, shaping the distinct characteristics and uses of these two varieties within the Cannabis sativa species.