Is Cannabis a parasite on humans?

Whatever the silliness and arrogance of his views on religion, the Dawkins of _The Extended Phenotype_ continues to fascinate me. The idea that genes are selected as much for their effects on other phenotypes as on those of the bodies that carry them is one of these simple, blinding illuminations that make you wonder how anyone could not have seen it before.

Most of his examples are about parasites of lower animals — my favourite a fluke which makes ants climb to the top of blades of grass, where they are more likely to be eaten by sheep, which are required for the next stage of the fluke’s lifestyle.[1]

But you can perfectly well understand the plants addictive to humans in the same way. Or, indeed, brewer’s yeast. The genes that cause cannabis to generate THC or tobacco to generate nicotine, also act on human brain phenotypes in ways which cause humans to behave in certain ways — ie to plant them, nurture them, breed them selectively, etc, which increase the population of such genes in the world. Whether you regard this as parasitism or symbiosis is a nice point, but I think on balance it is parasitism.

So I think this is a clear example of the way in which Dawkins is quite simply right to see that genes have an existence independent of the bodies they find themselves in. At the same time, it is a deficient example of causation. It’s true that certain genes in certain plants make humans behave in certain ways. But we all know huge differences in individual tolerance and reactions. Nor do drug chemicals make whole societies behave like that. Some societies invent vineyards, some, prohibition. So, while it is clearly true that tobacco grows in Macedonia today and cannabis in wardrobes in Enfield, because of the effect that the products of some of their genes have on human brains, this is only an additive cause, one necessary rather than sufficient.

On the other hand, thinking of drugs as parasitic on humans — and from this it is a short step to the idea of their being spiritual or metaphysical entities, like “memes” — might be helpful as a way of turning people against their use, and thus in its own way effective. Like “Demon rum”, in fact.

fn1. this is from memory, and if I write the thought up for CiF I will check the details. Ant, grass, sheep are all correct. But I can’t remember which parasite.

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11 Responses to Is Cannabis a parasite on humans?

  1. Rupert says:

    I’m not sure this works. Can parasites survive independently of their hosts? Cannabis can and does grow wild. Its existence certainly modifies the behaviour of others, but then so does the existence of clay (says the man sitting in a brick-built flat).

    Genotypes don’t exist in isolation. At the very least, they live in dynamic equilibrium with their environment – and that environment can and should be seen to include other examples of themselves, and of other genotypes. All modify the others. There are many different categories of interaction — puppeteer wasps and their hapless victims, long-tongued moths and concomitant flowers, {cows, grasses, yeast} and Marmite toast for breakfast — and they all have some sort of overlap. Demonising one particular relationship by highlighting a mild correspondence with something viscerally vile is propaganda, and not the useful sort.

    In any case, the relationship between humanity and the psychoactive is far more complex than any sort of parasitic business. It involves all manner of questions of consciousness, self, free will, causality, socialisation, spirituality and so on. It’s also exceptionally varied, from touching the mind of God or coming to understand your friends to pissing yourself in a gutter or driving a car into a child. “Turning people against their use” is much like preaching abstinence as a cure for AIDS and eating less as a cure for obesity – sounds great from the pulpit and will doubtless get you a government grant, but it won’t have any effect on the fat promiscuous druggy drunks out there. Who may, just possibly, be happily obeying ther genotypical imperative for perfectly good reasons.

  2. Paul Crowley says:

    Not really; saying that drugs are parasitic rather than symbiotic is just another way of saying that they are “bad, mm-kay”. Also, it’s not just a relationship between consumer and plant; the seller plays a pivotal role.

  3. Ben says:

    “How clever of sheep to evolve shepherds”

    I like the ‘symbiotic is just another way of saying that they are “bad, mm-kay”’. But anyway, to bring it full circle, the whole idea reminds me of the theory that agricultural society grew from the need to grow grain for beer, rather than bread. Thusly modern society could be the result of yeast evolution, which in turn brings us round to Ben Franklin’s statement that beer is proof that God loves us and wants us to be happy.

  4. acb says:

    Rupert, and to an extent Paul: I know that the relationships between anything human and almost anything else can’t be reduced to biology, and certainly not by us. That’s the point of saying that societies react in different ways.

    Rupert: “Can parasites survive independently of their hosts?” no — but neither can highly domesticated animals, nor, for that matter, skunk. I think it’s a bit like wolves and dogs. Domesticated dogs are clearly, to a martian biologist, parasites of humans. But they evolved from wolves, which are not. Wolves, incidentally, have brains a third larger than dogs. My guess is that the energy that a skunk plants puts into generating THC is removed from some activity which would be more useful, if not vital, outside a well-lit wardrobe. Clay isn’t alive, and so can’t be a parasite.

    It is entirely possible that some drugs are almost always bad for people. Crystal meth looks like a pretty good candidate. Many are definitely bad for adolescents. Alcohol has had, and continues to have, a devastating effect on some populations. So I don’t have any problem with saying sometimes they are bad. I don’t have any problem with people believing whatever they need to in order to break addictions — I am a great supporter of AA, for example. Of course, I believe that most of the plants that produce chemicals that interest people are symbionts. But nicotine? Note that the fact that they give us _pleasure_ proves absolutely nothing in this context. It is simply their mechanism for influencing our behaviour.

    Ben, if agriculture did arise from beer, my argument is strengthened. It was a huge backwards step in almost every respect. OK, after several hundred generations, Europeans evolved a capacity to deal with alcohol.

  5. Rupert says:

    I think skunk could and would survive, as do feral dogs, although how well either would do in the long term is moot – we’d have to agree what long term is, apart the place where we’re all dead. The sort of energy and resources put into breeding show dogs could be more usefully deployed in other ways too, but that argument can be made for almost everything we don’t have to do but do anyway. Is all of culture to be seen as parasitical on an otherwise useful race of primates? (and I’m not sure why the live/dead distinction makes any difference, if we’re looking at things from a purely human point of view).

    Drugs, like everything we do, are susceptible to the sailor’s instinct that if a little of something is good then a lot is better. Combine that with our infernal ingenuity, and we’re always going to be wandering into positive feedback that can go badly wrong (see also: technology of war, use of energy, sugar, television channels and CiF). An aspirin can kill someone, a lifetime’s heroin addiction can go undiscovered. Crystal meth doesn’t have a lot to recommend it but it’s not going to come close to causing the harm that booze does and it does have legitimate medical uses. And then there’s the possibility of inventions like the cocaine vaccine – one shot, and no more buzz. Is that a good thing? What if it has side-effects?

    And I must take issue with beer being a huge step backwards in almost every respect. It’s a very useful way of sterilising water, which at the time of discovery must have had an enormous effect and one that continued to be important until the 19th century. It breaks down personal and social barriers. It makes people happy. It tastes lovely, and it annoys puritans.

    Perhaps civilisation would be better if we supped distilled water. I’m not sure the evidence supports that.

  6. jim says:

    Maize can’t survive without humans.

  7. Dicrocoelium dentriticum is the fluke that encysts in ant brains and alters their behaviour. I remember undergrad discussion as to what a parasite is, and the definition included some structural alteration to allow it to exploit its host. Does a plant producing an addictive molecule come into that category?

  8. acb says:

    How big must the structural alteration be to count? Presumably the ur-cannabis produced a lot less THC than skunk does, and the increased production is in some sense the result of a physical change in its genome. Mind you, I disagree with Rupert in that I don’t think that skunk could survive in the wild, any more than most show dogs could.

  9. nikete says:

    D. dendriticum is the name of the parasite.

  10. a9ymous says:

    You may find Michael Pollan’s book The Botany of Desire interesting reading, as he describes plant evolution from a similar viewpoint. The potato, tulip, apple and cannabis plants are each discussed, as having evolved qualities attractive to humans has caused them to prosper and diversify far beyond how they otherwise would have.

    I don’t really wish to enter this debate but cast my vote for symbiot over parasite.

  11. HempSymbiote says:

    Cannabis has been shown to kill tumors, treat many diseases, its seeds include every vitamin and nutrient required for human survival, you could literally live off of them.

    Even what seems to be a negative effect paranoia, has benefits. When you are paranoid on pot you aren’t running around screaming “OMG! OMG!” you don’t panic you remain calm but might say things like “dude was that a cop” or “we should get out of here”. And the paranoia is almost always an exaggeration of real signs that something could be wrong. A car approaching is probably not a cop but you are hyperaware that it could be. This would be a very useful mindset in the wild, always alert to danger such as predators or maybe the alertness that encompasses the paranoia will also extend to prey but at the same time you are calm and also less likely to invent dangers(you just exaggerate them). It would also be useful for spies or warriors(the hashhashins or hash-eaters comes to mind). Except that pot lends itself against violence but if you were trained to and planned on it ahead of time the combination with the heightened alertness and calm cool thinking could be a bonus in stealth or combat.

    Cannabis is the oldest symbiote, going back very early into our history and once we started domesticating it we strengthened our symbiotic relationship. Its only in recent times when we have started demonizing our natural, biological partner. This has only lead to misery and destruction. With hemp we can make paper and stop killing the trees. With hemp oil we can fuel cars, we don’t have to keep burning fossil fuels and destroying the atmosphere. Many of the world’s problems are because humanity largely abandoned cannabis in the past century. Its time for us to come back to it.

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