Now for a bit of trivia: On this day in 1844, British naturalist Charles Darwin confessed in a letter to a friend, “I am almost convinced (quite contrary to the opinion I started with) that species are not (it is like confessing a murder) immutable.”

This 169-year-old quote hints at Darwin’s internal struggle with the revolutionary idea that made him famous. It also sets the scene for our next giveaway book. Shaking the Foundation: Charles Darwin and the Theory of Evolution, from Twenty-First Century Books, is an intimate exploration of one of the biggest game-changers in the history of science. 

Wondering how Darwin came up with his theory? Curious about the personal crisis it sparked for him? Maybe you’re just here for the epic showdown: the fiery ongoing controversy inspired by Darwin’s ideas, which has persisted in various–often surprising–forms. Shaking the Foundation has it all. From Darwin’s private battles to the Scopes Monkey Trial to today’s school curriculum debates, the story of this intrepid little theory is not quite as dramatic as a murder confession…but close.

To win a copy of Shaking the Foundation for the lucky upper grade reader(s) in your life, leave a comment below or Tweet this line: “Free Book Friday! RT to win SHAKING THE FOUNDATION from @Lernerbooks! http://bit.ly/1OrSN.”