Very slowly, I imagine. Or at least slower than “regular” species.

Assuming that a colony of ants operates with multitudes of workers, males for mating, and a solitary queen, the standard family tree is horribly disrupted. With non-social insects, the evolutionary output should be dependent solely on the two animals mating. Two beetles mate, their offspring go to larvae-care, then progress through pupae school, and eventually graduate to become reproducing members of the species. If some of the beetles posses traits that improve their ability to survive and subsequently reproduce then those traits will propagate, or at least have a higher probability of propagating.

This is so because the individual beetle is what I think of as the biological accounting unit. Its genetic fitness is dependent solely on it (and its mate). However, the mating pairs in an ant colony, the queen and her male(s), cannot on their own propagate the species. They require many, many more workers to do this, and thus an entire colony arrangement must be the biological accounting unit.

This is probably a bit simplified, because if a colony might be able to go on indefinitely, what with being able to replace the queen (assuming a colony can work like this). So let’s say that the biological accounting unit is a specific queen and the colony supporting her. This means that the variability in individual ants will have remarkably little effect on the evolution of future generations. What will matter, however, is the variation of the colony as a whole from the species average, and the survival of the biological accounting entity, the colony.