>>11655930That but also they provide more resources. Think of it in modern terms. We'll just use males to make it easier.
>each adult male earns $50,000 annually>each adult male spends $30,000 annually>each adult male has $20,000 left over>couple A has 4 sons>each one has 4 kids each>16 kids total>the 4 adult sons have $80,000 remaining >each child gets $5,000>couple B has 4 sons>three sons have 4 kids each, the other one is gay>12 kids total>the 4 adult sons have $80,000 remaining>each child gets $6,666.66Assuming everything is equal, Couple B's grandchildren should have about 33% more resources than couple A's. Even though there are less of them they should, ideally, be more fit and able to reproduce.
There's probably a lot of balancing required and it's not going to be perfect (you wouldn't want all gay kids, obviously), like all things in biology, though.