Friends are important. And long-standing friends are so rare and so precious that they can hardly be overvalued. But if humanity, as a species, were to name one friend that had been there since the very beginning, it would be certainly be...well, dogs. They were our evolutionary companions from early on. They are a part of our mythologies, our legends, and our tall tales.
But while we can imagine that people have always loved their dogs, there's actual evidence to back it up as well. As Indiana Jones would tell you, archeology is the path to many abilities some would consider to be unnatural. (Wait, I think I messed up that quote