Fine. Make the universe work for it. The whole system becomes more resilient as a result.
Look at our immune system. Incredibly complex and clever, and able to keep us alive in the face of all sorts of pathogens. It exists because of this cat and mouse game, played over millions of years.
There's people in the highlands of PNG who regularly eat each other. Of course, many are thought to have died due to prion diseases. But now these tribespeople seem to have become largely immune to prion disease. Incredible.
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).
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.
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.
