Professor Everett Mendelsohn's kickoff Darwin150 lecture at the Harvard Science Center. Professor Emeritus at Harvard, Everett Mendelsohn is credited with helping to invent the discipline of the history of science. And he's a wonderful speaker to boot.

In this first lecture of the Darwin150 campaign, Professor Mendelsohn explains "The World Before Darwin" - the intellectual currents that set the context for Darwin's theory to emerge.

Darwin150/Darwin Facebook group volunteer Kendall Crolius is the host on the video introducing this lecture and the Reading Odyssey campaign to celebrate 150 years since the publication of Darwin's "Origin of Species."

Enjoy.