RACHEL MARTIN, HOST:

Things change, species adapt - a bit oversimplified, but it's more or less what Charles Darwin concluded from his research in the Galapagos. The archipelago that inspired his theory proved that point again earlier this week. A natural bridge called Darwin's Arch eroded and collapsed into the sea. Just days later, the landmark already had a new nickname - the Pillars of Evolution. We'll keep you updated as the story evolves and evolves and evolves. Transcript provided by NPR, Copyright NPR.