You explain why but not how. Is it a spandrel from some other evolutionary trait that eventually became something important? Is it a process of higher-order bra

You explain why but not how. Is it a spandrel from some other evolutionary trait that eventually became something important? Is it a process of higher-order brain functions that we have? Is there an alternative method that brought this about (stuck in a proverbial room with only a fruit basket and no way out)?