Adventures in Evolution. http://www.youtube.com/watch?v=vmphlbRhLu8. HMS Beagle. Darwin did a 5-year voyage on the HMS Beagle Darwin stated “ the voyage of the Beagle has been by far the most important event in my life and has determined my whole career”.
When he returned he read the a book by Thomas Malthus that described how hunger, starvation, and disease would ultimately limit human population growth (1798)