On a small but densely packed Pacific archipelago off the coast of South America a young man had a startling idea reinforced by what he saw before his eyes. Multiple organisms that were related to one other had evolved differently in the separate island environments they were subjected to. But was it the environment that changed the organisms directly, or was there some other explanation for their survival? Might not the organisms themselves be an instrument of change in the manner in which they lived?
The beginnings of that journey led to the most startling and controversial theory explaining evolution and the origins of planet wide diversity, one that is still being hotly debated today.