So where did this idea of evolution come from. Well or there is there are always ideas are you can go back to Aristotle in find elements of evolutionary thought and Aristotle is a 19th Century idea and in order to see how it develops let's go back to about 79 year 1800 so at the end of the century of the environment. At that point if you were to ask a well-educated person living in a Western culture how old the world is they would take thousands of years and if you were to ask them well where did all the species on the planet come from they would say they were all created just the way to work now and they've never changed and if you ask them have there ever been any species that went extinct they would say no everything that was created is still alive and can be found somewhere on the planet so when Alexander von Humboldt who was certainly a creature of the enlightenment set out to explore South America he thinks that he might encounter some of those strange fossils did the French have been turning up in the Paris basin on top of a tap away in Venezuela so he really thought that there was a lost world of course Arthur Conan Doyle later wrote the novel about that but I mean these guys actually thought I go to Venezuela I go to the Congo I might meet a Brontosaurus that was what I thought.