June 11, 2015

"How a history of eating human brains protected this tribe from brain disease."

A grisly but jaunty headline for a WaPo article that begins:
The sickness spread at funerals.

The Fore people, a once-isolated tribe in eastern Papua New Guinea, had a long standing tradition of mortuary feasts — eating the the dead from their own community at funerals. Men consumed the flesh of their deceased relatives, while women and children ate the brain. It was an expression of respect for the lost loved ones, but the practice wreaked havoc on the communities they left behind. That’s because a deadly molecule that lives in brains was spreading to the women who ate them, causing a horrible degenerative illness called “kuru” that at one point killed 2 percent of the population each year.
So brain-eating caused disease and the people who didn't die it but lived to propagate their genes passed on resistance. That's the kind of PR deadly diseases are always flogging.

If you get past the titillating native-rituals material, there's more to the story:

When the researchers looked at the part of the genome that encodes prion-manufacturing proteins, they found something completely unprecedented. Where humans and every other vertebrate animal in the world have an amino acid called glycene, the resistant Fore had a different amino acid, valine....

That minute alteration in their genome prevented the prion-producing proteins from manufacturing the disease-causing form of the molecule, protecting those individuals from kuru. To test whether it might protect them from other kinds of prion disease, Collinge — the director of a prion research unit at University College London — and his team engineered the genes of several mice to mimic that variation.

23 comments:

Mac McConnell said...

Interesting, but old news.

Michael Brand said...

Read Richard Rhodes excellent book, 'Deadly Feasts'. It opens with a chapter on the Fore and Kuru.

Fen said...

Gee, maybe that's one reason civilizations created a stigma against cannibalism.

Maybe there are valid reasons for other "stigmas" too.

Fen said...

Anal sex is bad for the tribe because it allows disease to vector into pathways that evolution hasn't shielded against...

Michael K said...

"Maybe there are valid reasons for other "stigmas" too."

The prohibition against pork was probably based on experience with trichinosis.

tim maguire said...

Fen said...Maybe there are valid reasons for other "stigmas" too.

Probably all stigmas have an original in practical response to a serious problem. Hindus can't eat their cows during the famine because they will need the cow to plow their field when the rains come. Better to let your child starve than eat your cow and have the whole family starve later.

rhhardin said...

Man cow disease.

tim maguire said...

A point I meant to make but forgot is, oftentimes the stigma persists after the reason for it ceases.

Fritz said...

Fen said...
Anal sex is bad for the tribe because it allows disease to vector into pathways that evolution hasn't shielded against...


But if you make it a tradition, eventually evolution takes care of the problem, one way or another.

Sammy Finkelman said...

Where humans and every other vertebrate animal in the world have an amino acid called glycene, the resistant Fore had a different amino acid, valine....

Could the mutation be that rare??

And the disease is supposedly passed along only by cannibalism, and the cannabalism among the Fore was new, as far as we know.

Well, first of all, we're only talking about one gene. There's a new variant there.

The thinking is, the mutation happened in only one person (and there could have been other mutations that also protected a person, and in fact there's another, more common, mutation in the same gene that also protects against kuru.)

Here is a 2009 article in the New Scientist about this:

http://www.newscientist.com/article/dn18172-gene-change-in-cannibals-reveals-evolution-in-action.html

This is a 2003 article article in the New Scientist about the other mutation:

http://www.newscientist.com/article/dn3615-cannibalism-rife-among-prehistoric-humans.html

They wanted to prove long ago cannabalism, but there's an argument that the danger came from eating certain animals. The mutation discovered around 2003 exists around the world, but the 2009 mutation is new.

Monkeyboy said...

I was just re-reading "Dream Park" by Larry Niven. The Fore and Kuru have a big part in the story.

When describing Kuru one of the characters says something like "how long do you have to eat human brains before an organism evolves to take advantage of it?"

Eric the Fruit Bat said...

A similar process explains why hardly anyone who takes communion ever gets crucified.

pfennig said...

BRAINLESS BODIES IN TOPLESS COMMUNITIES

Fen said...

"oftentimes the stigma persists after the reason for it ceases"

Sure. But stigmas also persist long after their causes are forgotten.

Mary Beth said...

How a history of eating human brains protected this tribe from brain disease.

2% died per year. I think a history of not eating brains would have better protected this tribe from brain disease.

Mary Beth said...

If I remember correctly from a religion class in college a million years ago, and if the professor was right, some religious taboos against animals were a reaction to neighboring people who had the animal as a totem or used it in religious sacrifice.

Ann Althouse said...

"Interesting, but old news."

The article reports on a study published this week: "Researchers say the finding is a huge step toward understanding these diseases and other degenerative brain problems, including Alzheimer’s and Parkinson’s.""

Ann Althouse said...

Fen said... "Anal sex is bad for the tribe because it allows disease to vector into pathways that evolution hasn't shielded against..."

Oh, for the love of God. It took one hour for Fen to arrive and exhibit his phobia about anal sex. But by the logic explained in the article, a tribe that practiced a lot of anal sex would experience losses but ultimately become stronger and more able to fend off those diseases.

YoungHegelian said...

Oh, for the love of God. It took one hour for Fen to arrive and exhibit his phobia about anal sex

Don't worry, professor. We've got Lazlo to balance out Fen's phobia- with his philo-.

It all comes out in the wash.

William said...

I see this as a back handed tribute to Christopher Lee. Although vampires dine exclusively on blood, Christopher made an effort to increase diversity in the undead community by having open luau nights where zombies and vampires dined together on their victims.

Anthony said...

It all comes out in the wash because we've evolved really good laundry detergents.

Are populations where anal sex is (has been) more common more resistant to diseases spread that way?

Eric the Fruit Bat said...

There must be a gazillion washed-up STDs out there, crying in their beer.

Evolution's a bitch.

tim maguire said...

Blogger Fen said..."oftentimes the stigma persists after the reason for it ceases"

Sure. But stigmas also persist long after their causes are forgotten.


I don't see the difference between your statement and mine.