For over two centuries, Jean-Baptiste Lamarck's vision of inherited experience was dismissed as a scientific embarrassment, while Darwin's natural selection stood alone as evolution's engine. Now, through the quiet language of epigenetics — chemical tags, small RNA molecules, and transgenerational memory — biologists are finding that organisms do, in measurable ways, pass the lessons of their lives to their descendants. The story of life's adaptation, it seems, has always had two authors, and we are only now learning to read both.