Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: neilep on 09/09/2021 19:16:49

Title: How Do Isolated Tribes Survive Inbreeding Birth Defects ?
Post by: neilep on 09/09/2021 19:16:49

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 ?




 

Title: Re: How Do Isolated Tribes Survive Inbreeding Birth Defects ?
Post by: evan_au on 09/09/2021 22:17:37

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...

Title: Re: How Do Isolated Tribes Survive Inbreeding Birth Defects ?
Post by: Petrochemicals on 10/09/2021 00:29:41

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

Title: Re: How Do Isolated Tribes Survive Inbreeding Birth Defects ?
Post by: Bored chemist on 10/09/2021 08:43:32

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

Title: Re: How Do Isolated Tribes Survive Inbreeding Birth Defects ?
Post by: TommyJ on 23/09/2021 09:53:29

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 (https://en.wikipedia.org/wiki/Survivorship_bias#In_studies_of_evolution)  has studies on that.
3. They might not be so isolated yet, throughout their history.

Title: Re: How Do Isolated Tribes Survive Inbreeding Birth Defects ?
Post by: Just thinking on 25/09/2021 20:44:51

Quote from: neilep on 09/09/2021 19:16:49

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.