Everyone loves a good comeback story — but they don’t just apply to athletes and washed-up actors. Revivals can happen for ideas, places — even entire species. On this episode of The Pulse, we explore how and why comebacks happen in the scientific realm. We’ll hear stories about how grizzly bears are starting to rebound, the unexpected revival of Lamarckian evolution, how flatworms regenerate their bodies, and the psychological power of nostalgia.

Also heard on this week’s episode:

• For decades, talking about UFOs was sure to earn you some strange looks. But now that more credible accounts are emerging, that could be changing. For this story, we hear from investigative journalist Leslie Kean, Vincent Aiello from the Fighter Pilot Podcast, and Jill Tarter from the SETI Institute.
• Alejandro Sánchez Alvarado — a molecular biologist at the Stowers Institute for Medical Research in Kansas City — talks about the regenerative abilities of flatworms and salamanders, and how that might help us better understand our own biology.
• Paleontologist and University of Washington professor Peter Ward on the life and work of naturalist Jean Baptiste Lamarck — and why his controversial ideas on evolution are making a comeback. Ward’s book is called “Lamarck’s Revenge: How Epigenetics Is Revolutionizing Our Understanding of Evolution’s Past and Present.”