In 1859, Charles Darwin published On the Origin of Species — a book that quietly overturned centuries of belief about how life came to be.

In this episode of Decode: Science, we explore the core of Darwin’s theory of natural selection, in his own words and in context. Why did Darwin wait two decades to publish? How did he build a case without genetics? And what does “survival of the fittest” really mean?

Join us as we decode one of the most beautifully argued — and hotly debated — scientific works in history.