David Whalley asked:
Is it evolutionarily advantageous to be a cannibal?
Dave - I guess it depends what you are and how many diseases you’ve got that are going around. The big disadvantage to being a cannibal, evolutionarily, is that if you’re eating something of your own species, it can get all the same diseases that you can. And therefore: you eat them and then you get all of their diseases and then you die.
Chris - Yeah, that’s exactly what happened to the Fore people in New Guinea who developed a disease called Kuru, which was a prion disease - a bit like Mad Cow Disease but it was a human equivalent. And because it was a ritual for the women in the tribe to eat the brains of a dead relative when they buried them, there was an excess of women affected by this terrible neurological condition that came on all of a sudden. The actual word means “he who trembleth” in the native language because people got this BSE-like disease and they all died. It was first identified as a cannibalistically-transmitted tendency many years ago which means it’s interesting that people went and did almost the same experiment with cows and then were really surprised when BSE came along.
So I would say that actually, from an evolutionary point of view, it is not advantageous to be a cannibal, at least not for humans, and so that probably explains why the practice is so rare.
Dave - Although I guess in some other species, especially if you’re a very small animal which is quite short-lived and disease isn’t so much of an issue, if you’re really, really hungry then cannibalism is better than dying of starvation. So things like locusts will eat each other quite happily if they’re hungry.
Chris - So there you go, David Whorly 94: if you are going to be short-lived then it’s probably okay for you to be a cannibal – you may benefit from the increased nutritional benefits of eating your compatriots. Muscle has got lots of iron in it and lots of protein which will help you to build your own muscles up. But you could, if you’re going to live a long time, succumb to all kinds of nasty diseases so it will be disadvantageous.
My understanding is that there's quite a lot of evidence in the fossil record that cannibalism went on.
but, but, but, according to Flanders and Swann, "eating people's wrong"! Geezer, Tue, 14th Sep 2010
"You are what you eat", any truth to it?
Wolfekeeper, BSE (cows), Scrapie (sheep), Creutfveldt-Jacob Disease (CJD and Kuru for humans), and even Mad Hamster (squirrel, deer and so on) Disease all are transferred about equally between members of the same species, and are much harder to transfer cross species.
There are many cannibalistic species.
What about the scavenger species...
It was Kuru that was a problem in New Guinea, although it is probably the same disease as CJD which develops spontaneously in western populations. There is probably a genetic component but it transmits readily to others. It is important to remember in this context that new Guinean's who were cannibals were mostly only eating human brains as part of a ritual, not for food.
If there are any evolutionary processes involved, I think it is not in favor of cannabilism.
I think that this disease probably has a relatively small evolutionary potential and it is a major mistake to personalize mother nature. There are quite a number of pseudo random events in evolution that don't require an adaptational explanation. Prions are very likely one of those accidental happenings that is an emergent property of complexity that have directly made a few individuals very miserable, but the knowledge gained from understanding them can benefit many. SteveFish, Sun, 19th Dec 2010
It's not a matter of personalizing mother nature. She states the facts as it is. QuantumClue, Sun, 26th Dec 2010
There was no statement of facts, certainly not to the New Guineans who were just going about their lives and rituals. There was no way for these folks to connect what they did with a disease that took years to develop. It was western science that figured out what the practice and agent that caused their disease was, and when informed they stopped. SteveFish, Sun, 26th Dec 2010
My original point was that ''she'' that is, mother nature must have decided at one point, for a better word, that consumption of like beings was not acceptable. Hence why sporadic diseases appeared, because we were not supposed to consume our own. QuantumClue, Mon, 27th Dec 2010
The mother nature notion is magical thinking. SteveFish, Mon, 27th Dec 2010
Geezer, he may be using mother nature as a metaphor, but it is a bad one. He says "Hence why sporadic diseases appeared, because we were not supposed to consume our own" and this implies intention. This is one of the big mistakes many make regarding evolution or ecological imperatives. There is no one but ourselves to suppose that we shouldn't consume our own, and evolution does not work toward any particular outcome. I would like to know what we are supposed to do to avoid Huntington's chorea or Alzheimer's disease that we can learn from nature. Steve SteveFish, Mon, 27th Dec 2010
"Was that your ambition?"
I can't answer your question accurately and I have no information that would allow me to speculate. In general I prefer to stick to what people actually do or say and respond to that, it is more honest. SteveFish, Tue, 28th Dec 2010
No, mother nature is not an intellect, as a decision making machine. When I say this was mother natures way of telling us not to consume each other, I mean this in the sense, that nature has chosen? 1) a certain path where the biological nature does not entertain this way of life. The idiom mother nature is nothing more than a label many use today, and as Geezer said, I hope no one has misread this to mean that I somehow believe that nature is a decision making machine similar to human beings, or with some kind of intellectual personification.
I think cannibalism may be a result of where you live in some cases :)
Here's a disturbing video of someone suffering kuru
I posted some links... how come they haven't shown up? Do they need to be looked at first? QuantumClue, Tue, 28th Dec 2010
Don 't think so, you should just need to copy & paste them? yor_on, Tue, 28th Dec 2010
Cannibalism for food is rare, except in some notorious emergency situations. There is some anthropology research that suggests that it might have been more widespread in the past. The New Guineans ate some of the brain in a funeral rite, and the brain is the primary source of prions. So, if there is any path that has been "chosen" by nature, it is that a tenderloin, or a liver with some fava beans and a nice Chianti are just fine, but don't eat the brains. Cannibalism is not at all unusual in other animals, even primates. SteveFish, Tue, 28th Dec 2010
Interestingly however, the form of disease does take hold in the animal kindgom http://en.wikipedia.org/wiki/Bovine_spongiform_encephalopathy QuantumClue, Tue, 28th Dec 2010
Also there was a case where people from kentucky developed the disease from eating squirrel brains. QuantumClue, Tue, 28th Dec 2010
Yes, brains are potentially dangerous, although the cross species infection rate is pretty low. We humans made it much worse for the cows, especially in the UK where being a renderer used to be a cottage business. Carcasses of what in the US are called downer cows or sheep (alive, but so sick that it can't stand up) and other dead animals, including road kill, were rendered for fat by cooking at high heat. The remaining crumbles of protein were also sold to manufacturers of, mostly, cow chow. The thing about prions is that just normal cooking doesn't affect them, they have to be heated to above 460F (240C) to break down, so the soluble prions stuck to and were concentrated in the protein crumbles.
I came across a very worrying article:
The disease is very unfortunate for the few people who get it, but the Guardian article predicted only 13 cases a year over the next 20 years. SteveFish, Tue, 28th Dec 2010
How bizarre... when steve mentioned in the most extreme cases, the Crash of the Andes did come to mind. However, I do not believe they consumed the brains. They ate parts of the leg if memory serves. QuantumClue, Tue, 28th Dec 2010
I did know someone who claimed to have eaten sheeps brains on more than one occasion, on a seperate note. QuantumClue, Tue, 28th Dec 2010
I've read the book. Was that not them trying to justify eating brains? I don't believe they went as far as that surely? Reports and even interviews of the survivors speak of resorting to eating the flesh of the dead bodies... QuantumClue, Tue, 28th Dec 2010