Every time you nod along to your favorite tune or chit chat with a friend, an intricate system is at work making it possible. Your ears are biological marvels. There’s a lot going on in there. “It’s a very complex structure,” Anne Le Maître, an evolutionary biologist, biological anthropologist, and post-doctoral researcher at the Konrad Lorenz Institute in Austria, tells Popular Science. That complexity is the result of intense selection pressur…