[ujikoluk]

It is though, at the group level. The groups that adopt will have better survival than groups that don't, if the environment is such that parents regularly die while the cubs are small.

[shellfishgene]

If group selection happens is still much debated among biologists, and not at all resolved!

[beeflet]

Do you think group selection applies to eusocial species such as bees? It must. If so, imagine a species that is incrementally less social than eusocial. Unless there is some threshold degree of sociality required for group selection, then there clearly some level of group selection occurs for other animals (whether or not it's a major effect)