First Friend: How Dogs Evolved from Wolves to Become Our Best Friends by Kersten Hamilton

Long, long ago, when the world was new. . .a girl met a pup.

In those days, everyone knew that wolves and children could not be friends. Still, they learned from each other--how to hunt, how to trade, how to survive, how to play. And years and years went by, and the world spun and changed. And then--a boy fished with a wolf, and a girl traded with a wild dog, and animal and human grew up side by side. . .into the best friends we are today.