E35. Eighteen species of small brown bird on a pile of volcanic rock have taught us more about how evolution actually works than almost anything else on Earth. Not because Darwin figured them out. He didn't. Because a handful of scientists went back, banded every bird on one island, and watched it happen in real time. Scott heads to the Galapagos with Dr. Erik Enbody, Assistant Professor of Computational Biology at Cornell University, to find out how one ancestor became eighteen, why the beak is the only thing worth looking at, and what happens when species that aren't supposed to interbreed start swapping genes anyway.

In this episode you'll hear about:

• The island so small you can band every bird on it, and the drought that killed almost all of them
• One gene that explains 40% of beak size, when nothing in human height explains even 1%
• The finch that does something mind-blowingly villainous and what it says about how far evolution will go

All audio, video, and images in this episode are either original to Okay, But... Birds (© Okay Media, LLC) or used under license/permission from the respective rights holders. Media from the Macaulay Library is used courtesy of the Cornell Lab of Ornithology as follows:

• Large Ground-Finch audio contributed by Robert I. Bowman, ML85965
• Common Cactus-Finch audio contributed by Robert I. Bowman, ML86715
• Small Tree-Finch audio contributed by Robert I. Bowman, ML85464
• Vegetarian Finch audio contributed by Robert I. Bowman, ML82506
• Galapagos Mockingbird audio contributed by Robert I. Bowman, ML45963
• Española Mockingbird audio contributed by Herb Elliott, ML638777433
• Floreana Mockingbird audio contributed by Robert I. Bowman, ML85455
• San Cristobal Mockingbird audio contributed by Arnoud B. van den Berg, ML28656
• Palm Tanager audio contributed by Curtis Marantz, ML88937
• Blue-footed Booby audio contributed by Robert I. Bowman, ML85906
• Vampire Ground-Finch audio contributed by Robert I. Bowman, ML86756
• Woodpecker Finch audio contributed by Robert I. Bowman, ML82522
• Paradise Tanager audio contributed by Curtis Marantz, ML127399
• Galápagos Sea Lion audio contributed by Arnoud B. van den Berg, ML125020