[neilep (OP)]

Dear Anthropologists,


Well, the kweschun is in the title !


After a few millennia, how do isolated tribes still survive ? Their cousin may also be their brother, aunt uncle nephew niece sister type thing eh  ?


Surely they'd all be eating grass and playing banjos by now !!


whajafink ?




 

[evan_au]

I heard about an interesting trade pattern in New Guinea where a bride was purchased with sea shells.
- Since there are no sea shells on the central highlands, that led to a trade where brides moved from villages in the mountains down towards the coast, and shells moved from the coast towards the mountains.
- That would at least reduce inbreeding.

They didn't say how the tribe at the top of the mountains found their brides...

[Petrochemicals]

They have big enough gene pools that gradually disperse. I do not think they are as bad as the European royals.

[Bored chemist]

Many of them have taboos about inbreeding.
There's some evidence of a natural avoidance of close kin  breeding
https://www.nature.com/articles/6884280

[TommyJ]

1. Inbreeding is a problem for tribes with populations near to 50 or below.Tribal customs keep partners' relations far enough.
The European royal lines would be in the endangered group of 50 less.
2. Survivorship bias  has studies on that.
3. They might not be so isolated yet, throughout their history.

[Just thinking]

Surely they'd all be eating grass and playing banjos by now !!

I think the mountain people that live deep in the new guinea region are a bit strange it is believed that cannibalism is still a practice. Maybe if you don't fit in well you get eaten. If a child is born with two heads it goes in with the carrots.