At the heart of the success of the Beatles was the creative chemistry and volatile friendship between John Lennon and Paul McCartney. Listen as author Ian Leslie discusses his book, John & Paul: A Love Story in Songs with EconTalk's Russ Roberts. It's a deep dive into music and friendship as well as a revisionist history about how John and Paul created musical magic.

Should monkeys have the same rights as humans? What about elephants, ants, or invertebrates? NYU philosopher Jeff Sebo makes the case for expanding your moral circle to many more beings than you might expect, including those based on silicon chips. Listen as Sebo and EconTalk's Russ Roberts discuss to whom and what we owe moral consideration, how we determine a being's intrinsic moral significance, and why we have ethical obligations to others, anyway. They also discuss human exceptionalism--the idea that humans should be prioritized over other beings.

Bright colors, long tails, and dances of seduction: they may hurt a bird's chances of survival in the wild, but they seem to increase the chances of reproduction. Is this all part of natural selection or is sexual selection its own force in the bird world? Is there such a thing as beauty for beauty's sake? What can we learn from birds about the human experience of beauty? Listen as author and naturalist Matt Ridley speaks with EconTalk's Russ Roberts about a puzzle that kept Darwin up at night and that still troubles modern evolutionary biologists.