Season 2 Episode 10 - Home Again, Home Again, Jiggidy Jig

In this, the final episode of Season 2, Darwin does some island hoping, takes a surprising return trip to Brazil, and on October 2, 1836, finishes his 4 year 9 month journey. In this episode of the podcast we are joined by Dr. Belinda Sly, a evolutionary developmental biologist and colleague of ours, to discuss Darwin, his thoughts about the voyage, and if it had an effect on Darwin's mental health.

The final two chapters of the Voyage of the Beagle are unusual in that Darwin's writing style oscillates between dry technical accounts on how coral atolls are formed, and how different plants, insects, and animals naturally colonize these isolated islands in the middle of the ocean with very melodic and romantic descriptions of the landscapes and peoples he encountered on these far away islands.

Atolls

http://geologylearn.blogspot.com/

One can imagine how disorienting sailors must have been when they first encountered the unusual geological structure of an island atoll.

http://geologylearn.blogspot.com/

A ring structure of land that either encompasses a calm marine harbor that may or may not also include an island in the middle, as seen in the Bora Bora atoll above. Darwin proposed that these unique structures came about through two natural process occurring at the same rate. The volcano that rose from the deep ocean floor and erupted to originally form the island would go dormant and begin to erode away.  Once the volcano had cooled, marine corals would begin to colonize the new island in the shallow waters to create the coral reef. Slowly the volcano would subside back into the ocean and concurrently the corals would grow upward and outward at the same rate as the island eroded and sank.

http://darwin-online.org.uk/

Darwin was the first to actually propose the correct geological model for atoll formation and he spends many pages of Chapter XX explaining his model.

Unfortunately Dr. Josh Adkins was unable to join us on the final episode but you can get your Josh fix by listening to his award-winning podcast The CromCast, a podcast dedicated to weird fiction that also has the occasional Bourbons and Barbarians episodes, a series that entertainingly combine bourbon with old school D&D.


The opening and closing theme to Discovering Darwin is "May" by Jared C. Balogh.

Interlude music is Remember the Way by Mid Air Machine