Even if there is no genetic program directly determining a language “module” à la Noam Chomsky and his ideas, the necessity of the similarity of human environments and the long stretch of cultural history which is effectively immutable means that even absent something hard-coded genetically, this quasi-module will still act and look much the same with nearly the same functionality given its effective operational fixedness by human cultural historicity.

Thus, we might never discover such a language module in our genes or by any ethical sort of scientific assessment but it’ll be there all the same. Arguing over the seat of language and its genetic component is, sort of like the altruism vs. egoism debate in philosophy, missing the point while scrutinizing the universe for dark matter with nothing but a flashlight.