Jonathan Kramnick wrote Against Literary Darwinism." Joseph Carroll responds. I will note that the brain has several levels, and the presence of modularity at one level hardly an argument against general intelligence. In fact, general intelligence in humans allows for a fuller integration of the modules, allows for their overlap, and allows for considerable mental flexibility such that we have been able to adapt to almost every physical environment on earth. However, there are instincts and modules (are there overlaps?) that do restrict the kinds of social environments we can live well in, and it is thus important to understand the human brain at both levels.
As far as literature is concerned, it seems likely that literature -- storytelling -- is emergent through our general intelligence that synthesizes much of what goes on in our brains. Imagination combined with narrative (which is pre-human, existing in anything that hunts or tries to escape from hunters) and language (which itself has narrative structure in its grammatical structure) are all present in the human brain, and are combined to create stories at the level of general intelligence. In turn, as Carroll argues, "literature is adaptive precisely because it is a medium for cognitive flexibility."
The one thing Carroll does not make explicit, though it is implied, is the fact that when critics such as Kramnick use "history," they mean there is no biological basis, that it is entirely socially constructed, which in turn implies the blank slate theory of the brain. Literature is not considered by people like Kramnick to be "natural," but only historically contingent. Which makes it hard to understand the presence of stories in every culture throughout all of human history. A lot of energy is put into telling stories, and a lot of time and energy wasted in listening to them. If there is not some sort of adaptive benefit to stories, those cultures that did not tell them would have wiped out the rest -- or at the very least, we should be able to find a culture where stories don't exist.