Signing, Singing, Speaking: How Language Evolved : NPR: "These words you are reading are really just a collection of arbitrary symbols. Yet, after some decoding by your brain, these symbols convey meaning. That's because humans have evolved a brain with an extraordinary knack for language. And language has given us a major advantage over other species.
Yet scientists still don't know when and how we began using language."
"The Earth would not be the way it is if humankind didn't have the ability to communicate, to organize itself, to pass knowledge down from generation to generation," says Jeff Elman, a professor of cognitive science at the University of California, San Diego. "We'd be living in troops of very smart baboons," he says.
Instead, language has allowed us to cooperate in groups of millions instead of dozens, he says. It also lets us share the complex ideas produced by our brains, and it's flexible in ways you don't find in the communication systems of other species.
Bees, for example, use an elaborate communication system to tell one another precisely how to get from the hive to a source of pollen, Elman says. "But that's all it does," he says. "They can't talk about politics. They can't talk about who's having an affair with what other bee — and these are things that we can do."