Maybe not in the bulletproof sense, but it seems pretty obvious that since human beings raised without language cannot learn it as adults or even as teenagers, the facility for learning language at a particular age is an evolved trait. That and the fact there's strong evidence neanderthals used language means language is effectively older than our species. All known languages and language groups within the last fifty thousand years, therefore, are just the distant descendants of a language five, ten, or twenty times older. Those "bragging rights" are scientifically irrelevant.