Who knows? Cannabis use is old. Way old. How old? We don't know. But if it is on the order of millions of years... think about it. And not just Cannabis. DMT is produced by the pineal gland.
Psychotropic Plant Consumption and Early Man
http://synthetic_universe.blogspot.com/2006/01/revolutions-of-consciousness.htmlWhat inspired the animal to look to the night sky and see, not just stars, but constellations, deities, and mythological stories? What forces drove the evolution of the primate brain to function beyond the boundaries of behavioral instinct and into a universe of perception which displaced time and space, projected meaning and purpose upon environmental elements, and established synthetic symbols and icons for subsequent cultural manipulation? What was it that initially delineated early humans from the physical constrictions of the natural world?
Carl Sagan speculates on such questions in his book, The Dragons of Eden, and offers a little food for thought. He considers a band of human Pygmies that intoxicate themselves on marijuana while performing mundane tasks like fishing or hunting. He casually ponders the possibility that “in human history the cultivation of marijuana led generally to the invention of agriculture, and thereby to civilization” (Sagan, 201). Of course, the “real” world is perhaps a bit more complex than that. The forces that drive human evolution are vast, and modern science continues to unwrap the mysteries of our ontological existence. The fact that every human culture at some point in history practiced the consumption of at least one version of a psycho active substance shouldn’t be ignored when considering the evolution of the human animal (Weil, et al, 10). Some scientists studying the molecular composition of flora have found evidence to suggest a symbiosis between psychoactive plants (i.e. entheogens) and indigenous wild-life consumers(3).
ENTHEOGENS AND ANIMALS:
Psychoactive plants typically manufacture chemicals analogous to neurotransmitters functioning within the mammalian brain(3). Morphine from the opium plant mimics the function of endorphins, and certain cacti like Peyote produce ergot alkaloids and mescaline, which mimic serotonin(3). Tobacco produces nicotine that mimics acetylcholine, coffee beans produce caffeine which mimics adenosine (3), and marijuana produces THC that mimics Anandamide(3). Anthropologist R.J. Sullivan suggests that many of the psycho active plants which mammals consume provide necessary nutrients for brain operation, especially during times of potential malnutrition when food resources become scarce. During these times, mammals that consume psychoactive plants receive many of the chemical compounds necessary for efficient brain function and can survive until other food sources are found(3). Plants that manufacture analogous neurotransmitters potentially take advantage of ecological niches defined by mammalian consumption. Seeds, which can’t be digested, may be transported by an organism and deposited within excrement to a new location, and the boundaries of a plant’s ecological niche are expanded.