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For centuries, the Fore people of Papua New Guinea participated in a morbid funeral ritual. When one of the tribesmen died, his wife, sisters, and daughters would dismember him limb by limb, then eat his brain as a sign of respect. In the 20th century, the Fore began suffering from kuru—a brain disease that resembles mad cow (Creutzfeldt-Jakob) disease.
More than 2,500 Fore died before researchers realized that ingesting human brains could cause the disease. Yet some Fore never developed kuru and seemed to be resistant to it. Scientists believed that a genetic mutation might have protected these Fore.
Simon Mead of the University College of London and his colleagues compared DNA samples from 152 Fore who died of kuru and 3,000 living Fore. More than 700 of the Fore in the sample participated in eating human brains before the practice was banned in the 1950s. The researchers found a variant of PRNP, the gene that makes prions. With kuru, malformed prions develop, causing a chain reaction that transforms the brain into a mush. A variation on codon 129, dubbed G127V, protected about 51 Fore from being susceptible to kuru. None of the 152 known kuru sufferers carried the variation.
“I hope it will become a textbook example of how evolution happens,” Mead says. This anti-kuru gene shows how the human body adapts to protect itself from impending danger.
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BRAAAAAAAIIIIIINNNNNSSSSSS…..
posted by Craig on 11-25-2009 at 12:29 pm
one danger eating too much brain: transforming into a zombie
posted by Will on 11-25-2009 at 12:40 pm
I guess I’ll have to come up with a different menu for my Thanksgiving feast, getting kuru doesn’t sound very fun. Couldn’t you have written this one yesterday before I went shopping at the local morgue?
posted by Dru on 11-25-2009 at 12:51 pm
“This anti-kuru gene shows how the human body adapts to protect itself from impending danger. ”
No! Bad Mental Floss! This is not how evolution works! Your biology teachers would die of shame!
While this is still an example to how evolution works, it is not because the body is adapting to protect itself. Here’s a more likely hypothesis: Due random mutations, some one of the Fore tribe had the G127V mutation which protected them from kuru but this was not selected for until other members of the tribe began to die from kuru and we unable to produce more offspring. Kuru resistant members were able to produce more offspring due to their resistance, passing on the G127V mutation.
So, yes, this is a very good example of evolution, but through natural selection. Mutation don’t occur because there’s a need to protect the organism. Mutations occur through random chance.
posted by Liz on 11-25-2009 at 1:18 pm
It is not fair to classify a cultural rite as “morbid” just because you happen to be from a culture that disagrees with it. To the Fore this rite is far from morbid, it is a way to retain the memory and essence of their loved one beyond his or her death.
posted by Mia on 11-25-2009 at 10:34 pm
Yes and thank you and seconded to Liz.
posted by Anne on 11-26-2009 at 2:56 am
Cool! I now have a Thanksgiving Dinner Conversation Topic. :)
posted by Tdave on 11-26-2009 at 8:37 am
well as a student of anthropology and firm believer in boasian cultural relativity…it should be mentioned that the fore cultural rite stems a great deal from gender inequality. one of the reasons that the fore are discussed in classes today has to do with an apparent gender neutrality in the culture. however at deeper levels the gender differences are very pronounced. the reason it is the daughters and wives that eat the brain is because they are denied pork, seen as the absolute epitome of fine dining, which is reserved only for men. as a protein necessity the ingestion of human tissue is practiced and only among women as they are seen as unfit to waste good pork on. just thought id share some other angles of fore culture
posted by charlie on 11-26-2009 at 4:24 pm
OOooo, I did not know that! Thanks for the interesting tidbit about how this practice could have come around.
reCaptcha – Brain special
posted by Liz on 11-26-2009 at 5:51 pm
I feel the need to make an addition to Liz’s comment. (11-25-2009 at 1:18 pm) She is right to stress that it is random mutations allowing natural selection, not people adapting to dangers introduced to their environment. The original G127V mutation would occur whether or not they ate brains, it just happened to be beneficial in this case and be passed on as a result.
I would argue, however, that to say that this is a ‘good example of evolution’ is a bit misleading to the layman. It is a good example of natural selection and the microevolution that follows as the population changes through that natural selection. Just a personal opinion that grouping micro- and macro- evolution into the same word can be misleading, though it is technically correct.
posted by T on 12-2-2009 at 2:31 pm