[s1artibartfast]

Tribal or not, Paternal worry is also fundamental genetic strategy if you spend any resources caring for your children, as many mammals do.

The person who raises only others children is not longer expressed in the gene line

[azmodeus]

If the tribe is closely related, it can be a good strategy as a large part of their genes would still spread

[s1artibartfast]

sure, but the returns quickly diminish with relatedness. A child is worth two nephews/nieces, 8 first cousins once removed, or 32 second cousins once removed.

https://isogg.org/wiki/Autosomal_DNA_statistics

[pests]

That's assuming none of your nephews or first cousins never reproduce with each other down the line. Also consider it's not exactly your dna you are trying to pass on but your families. Then you are someone's child and nephew etc and those people want there genes passed on just as much as you do. So by raising others in the local community you help pass on your father's or uncle's DNA.

[toasterlovin]

This gets brought up to explain why homosexuality is partially genetic and the math just does not work out.