I was an English naturalist born the fifth of six children. My parents were wealthy, well-connected and open minded. I went to study at Edinburgh University, thinking I would become a doctor like my father and grandfather. But, I found surgery too much to stomach, so I went to Cambridge to study theology. This training left me plenty of time to pursue my true passion – biology!

After I graduated in 1831, I was asked to serve as the science officer on the H.M.S. Beagle on an exploratory survey of four continents. On this important voyage, I collected specimens, sketched, read and made notes about my findings. My careful observation revealed that life modifies itself based on breeding habits, mutation, the rigors of predation and food in its environment. And, more importantly, that those individuals within a species that are best suited to their environment survive longer and have more time to procreate. More offspring means these individuals’ characteristics are more likely to be passed on to the next generation, thus modifying the species over time.

I knew this was true. My research had proved it. But, I was concerned about releasing my findings. My grandfather had published a book about transmutation many years earlier and been ridiculed for his beliefs. I did not want to experience that, so I delayed the release of my work for 20 years.

In 1858, a colleague of mine, Alfred Russel Wallace, had independently developed his own theory of natural selection. Our findings were jointly presented to Linnean Society on July 1st, but it was my book, “On the Origin of Species by Natural Selection,” that ultimately garnered greater attention.