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Comment by awesome_dude | Hacker News Reader

We still get diseases though, proving the point that millions of years of evolution are still not enough to build a perfect defence.

Your comment on PNG, seems to ignore Kuru

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It explicitly mentions Kuru as "prion disease", it ignores that the mortuary practice of eating various parts of respected dead has long passed in time .. although the lingering effect on the woman and children that ate portions of the brain in the 1970s, early 1980s, is still residual in a very few.

From an evolutionary PoV a perfect defence is overkill - with two separate defences against prion diseases in that region it's only the rare variation that causes any issue - and that rarely occurs before a new generation is birthed - ie. 'perfect' from the PoV of the selfish genes.

The claim is that people in PNG are "largely immune" to these diseases, where kuru shows that they are not, and the "cure" was a stop in the practice, not some evolutionary upgrade

They are largely immune to Kuru - the number of people that could contract it (ie. the number who ate brain) was significantly larger than the number of people who actually did contract it.

The resistance came about via two separate "evolutionary upgrade"(s).

I cannot find any such claim in the literature.

It appears to me that, like BSE (aka Mad Cow disease) it really depends on exposure.

It was specifically endemic to the Fore, not so much to the Yate and Usurufa, and not particularly at all to other highland people in the general region.

There's a twofer that skittled the Fore, a ~1900 mutation that created a new form of infectious prion proteins, and a local variation that saw less uptake in the Fore of a resistant prion protein (alongside other resistant prion protein).

So, over the highlands region, there was general resistance thanks to several evolved variations, in one specific locale (the Fore) there was insufficient resistance to the mutation that hit a peak of 200 deaths / annum for about three years(?) in the late 50s.

I can't speak to "the literature", I just had a lot of conversations with the people on the ground (Mike Alpers, etc), on again / off again, since the mid 1960s.

Acshually a protective mutation was quickly being selected for (more precisely, the lack of it was strongly selected against).

Paper about Kuru and mutations referenced in comment here: https://news.ycombinator.com/item?id=49719102

The paper relies on the fact that people who were dying did not have the gene, but those that didn't ... did

That's not really enough to say "We have found the gene" - it's just really good data to warrant further investigation

Also, the incubation period of the disease is up to 50 odd years, have there been follow up studies?

> millions of years of evolution are still not enough to build a perfect defence.

Who said anything about a perfect defence? And since when was that the bar?

The context is very clear - but, sure you can play word games, why not.

Just, you're doing it on your own.

What seems obvious to you doesn't seem obvious to me. I'm not a malicious or incompetent enemy. But you will need to explain your perspective for me to understand it.

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