Half brother - Kenneth Oppel

Ben Tomlin has been an only child for thirteen years. So when his research-scientist parents bring home a baby chimp to raise as a human child, Ben's life is turned upside-down. Teaching a baby chimp how to understand language is not his idea of fun, especially when he's trying to settle in at his new school.

But it isn't long before Zan's infectious personality endears him to everyone and he becomes a real member of the family. But just what will happen when he grows up and the experiment comes to an end? Ben must take dramatic steps, and the repercussions ricochet through home and community with devastating results.

This phenomenal novel is a thought-provoking story of relationships and family, first love and growing up, ethics and dilemmas.