As a sophomore in college, I desperately wanted to major in theoretical linguistics, but I knew only three languages, and I was advised that this was insufficient for the major. Things might have been different if this book were available then: unlike most books about language evolution, Ruhlen's
Origin of Language actually gets you involved in applying standard linguistic techniques to carefully chosen examples--by the end of the book, you will have constructed a family tree of the world's languages. And you needn't know any other than your mother tongue when you start, but you'll probably want to go out and learn several more languages by time you are done. Recommended.
