It just happens, and the same is true about physical skills, like riding a bicycle, or swimming, or skiing if you can ski, these kinds of things. Each particular language has its own field which is usually established over centuries at least. The whole idea of morphic resonance is evolutionary , but morphic resonance only gives the repetitions. It doesn't give the creativity. So evolution must involve an interplay of creativity and repetition.
Creativity gives new forms, new patterns, new ideas, new art forms.
And we don't know where creativity comes from. Creativity is a mystery wherever you encounter it, in the human realm, or in the realm of biological evolution, or of cosmic evolution. We know creativity happens. And then what happens is a kind of Darwinian natural selection. Not every good idea survives.