The exploitation of Cannabis sativa by Homo sapiens
Cannabis sativa is a species of plant in the genus Cannabis and the family Cannabaceae that has been used by humans since the start of recorded history, (at least 3000 BC). It is a plant native to central and south Asia, but is now exported and grown in almost all parts of the world, although this cultivation and exportation is in some places illegal as it is a very controversial plant. The reason it is illegal in many countries is because of its psychoactive and hallucinogenic properties, which make it a popular recreational drug. Cannabis sativa does however have many other uses for humans, most notably being used as a fibre, when cultivated for this purpose it is known as hemp. This can be used to make clothes that are biodegradable which is arguably more environmentally friendly than some of the materials currently used. However even its cultivation as a fibre is banned in many places due to its potential as a narcotic. Depending on the aim of the cultivator of the Cannabis sativa plant (either to be used as a narcotic or as a fibre) they will select for certain characteristics when breeding the plants which will be beneficial for the final product. This will be looked at more in depth later on in the essay. Other uses of Cannabis sativa include as a bio fuel, as bird seed and as a medicine.
Cannabis sativa is a dioecious, sexually reproducing plant. This means that plants are either male or female, male plants contain a stamen but not a carpel and female plants contain a carpel but not a stamen. This ensures cross pollination will take place. In the wild this type of reproduction would mean that there was more variation between individuals, as plants are not just ‘clones’ of each other (because of self pollination which results in ‘a’ sexual reproduction). This variation would mean that the population would be more likely to survive if there was a change in the environment as there are a lot of different characteristics which could be ‘selected for’. This property of Cannabis sativa is relevant to cultivators because it means that they can breed two plants with strong desirable characteristics together, and the offspring will most likely inherit both the characteristics. Eventually through the cultivators ‘selecting for’ this specific characteristic the specimens being produced may be very different to the original plants used. This is similar to how natural selection ‘selects’ the best characteristics (adaptations) which helps organisms survive and this over time and accumulation of adaptations eventually leads to evolution. Over the millennia that Cannabis sativa has been cultivated by people, the varieties bred for hemp and drugs have become distinguishable in their appearance and in their biology, although they can still interbreed and produce fertile offspring so are still part of the same species.
One of the most highlighted differences between the varieties of Cannabis sativa used for hemp and narcotics are the THC (tetrahydrocannabinol) concentrations. THC is the psychoactive compound in the cannabis plant which is found mainly in the female flowering tops. In hemp plants it is usually below 1%, whereas in Cannabis sativa plants used for drugs it is usually between 4% and 9%. However when Cannabis sativa is interbred with Cannabis indica the THC concentrations can be as high as 30%. The fact that cannabis plants will easily breed with each other and produce fertile offspring has caused problems for hemp cultivators, as some countries and American states don’t distinguish between the low THC content hemp and the potent higher level THC plants. This is possibly because of the risk of higher THC level plants arising within the population. Hemp plants have a higher concentration of the anti psychotic cannabinoid CBD than in the drug strains (1), which further reduce the chances of the plant being used as something to become inebriated off....
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