If anyone is interested, here are 4 more programs available to listen to about Darwin's life, work, and travels. They're from a BBC Radio 4 panel show called "In Our Time" (a personal favourite).
Darwin: Life After Origins - http://www.bbc.co.uk/programmes/b00gdhqf
Darwin: On the Origin of Species - http://www.bbc.co.uk/programmes/b00gd3wy
Darwin: On the Origin of Charles Darwin - http://www.bbc.co.uk/programmes/b00g9z9x
Darwin: The Voyage of the Beagle - http://www.bbc.co.uk/programmes/b00gbf2g