How much do you know about the wacky weed and its odd effects? How exactly does marijuana provide its high, and who discovered the effects of smoking the plant in the first place? The marijuana plant isn’t used only for smoking; its fibers can also be made into rope or fabric. Perhaps the oddest use of hemp rope on record is as a method for transporting giant stone statues. In 2012, archaeologists created reproductions of Easter Island’s statues, trying to figure out how ancient people may have moved the iconic 9,600-lb. (4.35 metric tons) heads from their quarry. Theorists have suggested everything from log rollers to extraterrestrial help for the task, but in 2012, California State University Long Beach archaeologist Carl Lipo proved that all that was needed is hemp rope.
What’s the difference between hemp and pot, anyway? A single genetic switch. In 2011, researchers from the University of Saskatchewan announced that they’d discovered the genetic alteration that allows psychoactive cannabis plants (Cannabis sativa) to give users a high (as compared to industrial hemp plants, which are no fun for smoking).
In contrast, marijuana plants do produce THCA but don’t create much of a substance called cannabidiolic acid (CBDA), which occurs in abundance in hemp but competes with THCA for raw materials. Thus, hemp is rich in non psychoactive CBDA, while marijuana is chock full of mind-bending THC.
Smoking up could be a very different experience for men and women, according to a 2014 study in the journal Drug and Alcohol Dependence. In research on rats, Washington State University psychologist Rebecca Craft found that females were more sensitive to cannabis’ painkilling qualities, but they were also more likely to develop a tolerance for the drug, which could contribute to negative side effects and dependence on marijuana.
Marijuana’s high is getting increasingly higher. In 2016, researchers measured the levels of marijuana’s active ingredient, THC, in more than 38,600 samples of street marijuana seized by the Drug Enforcement Agency over 20 years. They found that the levels of THC rose from about 4 percent in 1995 to about 12 percent in 2014.
Meanwhile, levels of the non-psychoactive compound cannabidiol fell from 0.28 percent in 2001 to 0.15 percent in 2014, the researchers reported in the journal Biological Psychiatry. As a result, THC levels were 14 times the level of cannabidiol in 1995; in 2014, that ratio had grown to 80.
Marijuana dependence may have genetic underpinnings. A 2016 study uncovered three genetic variants associated with dependence. One variant is involved in regulating calcium in the blood and has been linked with opioid dependence; another is involved with the growth of the central nervous system, the researchers reported in the journal JAMA Psychiatry. The genetic variations were simply associated with dependence, and the study couldn’t prove that having one of these variants caused dependence. Nevertheless, the researchers found that the genetic variations they’d discovered also tend to occur in people with depression, which could explain why dependence and depression often go hand-in-hand.
In many ways, the move toward legalization of marijuana, particularly medical marijuana, is a return to the status quo … the very long-ago status quo. In America, before the 1906 Pure Food and Drug Act, cannabis was a common ingredient in medicinal tinctures, and sellers didn’t even have to mention it on their labels.
During the 1920s and 1930s, though, Mexican immigration to the United States spiked as a result of the Mexican Revolution, according to PBS Frontline. People moving from Mexico brought along the custom of using marijuana recreationally, and the drug became linked with public fears of the newcomers. According to U.S. Customs and Border Protection, the federal government waffled on making marijuana illegal even as states enacted their own laws — a strange mirror image of the legalization process going on today. Nevertheless, Federal Bureau of Narcotics Commissioner Harry Anslinger campaigned to quash recreational marijuana, an effort that led to the Marihuana Tax Act of 1937. This law allowed for the importation of marijuana, but heavily taxed it, making it too expensive for recreational use.
The world’s first-known pot dealers were the nomads of the Eastern European Steppe, according to a 2016 study.
The Yamnaya, traders from what is now Russia and Ukraine, may have traded cannabis throughout Europe and East Asia around 5,000 years ago, the researchers found. The plant itself was in use in both Europe and Asia at least 10,200 years ago and grew naturally across both continents. But the archaeological record shows a spike in cannabis use in East Asia around 5,000 years ago, right around the time when the nomadic Yamnaya established a trade route across the steppes. Yamnaya sites show signs of cannabis burning, suggesting they may have brought the habit of smoking marijuana with them as they moved about.