I thought about this a bunch of years ago, and I am not quite sure how much this matters. Often ants get sperm from multiple fathers, and then they’d be less related than siblings (although maybe they only start doing that once they are out of the unstable intermediate period between being not eusocial and being eusocial). Also, this leads to colonies producing fewer males than would be game theoretically optimal for the queen and to conflict between queen and workers (50/50 would be optimal), although that might be helpful on the species level? So I think most of the cohesion benefits from 75% kinship between daughters is offset by the 25% kinship between brothers and sisters and if the queen mates with 2 males instead of 1, then the kinship is actually less than with monogamous termites (which is most termites, while I think most ant queens mate with multiple males).
I do think the difference in kinship could make it easier to develop eusociality, but I think my above argument that you just need a queen, so adapting behaviour is a simpler program might explain better how ants got through the unstable period between being individualistic and being sort of eusocial better (also if you start out with two parents there is less marginal returns to another worker for the nest, so that might also explain why it happened so often in Hymenoptera rather than other nest building insects). There are some wasp species that sometimes decide to build nests together and do division of labour (protect nest, search food) even though they are unrelated, but I forgot their name (Most of my opinion above is informed by the Superorganism book from EO Wilson. He has some idiosyncratic beliefs when it comes to group selection, but I think when it comes to his analysis that the kinship seems marginally important, he seems right). The kinship could explain why ants developed it multiple times, but it doesn’t explain why termites even after developing eusociality didn’t expand further.
I thought about this a bunch of years ago, and I am not quite sure how much this matters. Often ants get sperm from multiple fathers, and then they’d be less related than siblings (although maybe they only start doing that once they are out of the unstable intermediate period between being not eusocial and being eusocial). Also, this leads to colonies producing fewer males than would be game theoretically optimal for the queen and to conflict between queen and workers (50/50 would be optimal), although that might be helpful on the species level? So I think most of the cohesion benefits from 75% kinship between daughters is offset by the 25% kinship between brothers and sisters and if the queen mates with 2 males instead of 1, then the kinship is actually less than with monogamous termites (which is most termites, while I think most ant queens mate with multiple males).
I do think the difference in kinship could make it easier to develop eusociality, but I think my above argument that you just need a queen, so adapting behaviour is a simpler program might explain better how ants got through the unstable period between being individualistic and being sort of eusocial better (also if you start out with two parents there is less marginal returns to another worker for the nest, so that might also explain why it happened so often in Hymenoptera rather than other nest building insects). There are some wasp species that sometimes decide to build nests together and do division of labour (protect nest, search food) even though they are unrelated, but I forgot their name (Most of my opinion above is informed by the Superorganism book from EO Wilson. He has some idiosyncratic beliefs when it comes to group selection, but I think when it comes to his analysis that the kinship seems marginally important, he seems right). The kinship could explain why ants developed it multiple times, but it doesn’t explain why termites even after developing eusociality didn’t expand further.