Tuck your napkin under your chin. We’re about to serve up a tale of love, loss, and lamb chops - with a side of genetic modification.

Several years ago we told a story about Amy Pearl. For as long as she could remember, Amy loved meat in all its glorious cuts and marbled flavors. And then one day, for seemingly no reason, her body wouldn’t tolerate it. No steaks. No brisket. No weenies. It made no sense: why couldn’t she eat something that she had routinely enjoyed for decades?

It turned out Amy was not alone. And the answer to her mysterious allergy involved maps, a dancing lone star tick, and a very particular sugar called Alpha Gal.

In this update, we discover that our troubles with Alpha Gal go way beyond food. We go to NYU Langone Health hospital to see the second ever transplant of a kidney from a pig into a human, talk to some people at Revivicor, the company that bred the pig in question, and go back to Amy to find out what she thinks about this brave new world.

The original episode was reported by Latif Nasser, and produced by Annie McEwen and Matt Kielty. Sound design and scoring from Dylan Keefe, Annie McEwen, and Matt Kielty. Mix by Dylan Keefe with Arianne Wack.

The update was reported and produced by Sarah Qari. It was sound designed, scored, and mixed by Jeremy Bloom.

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In this hour of Radiolab, stories of cross-species communication.

When we gaze into the eyes of a wild animal, or even a beloved pet, can we ever really know what they might be thinking? Is it naive to assume they're experiencing something close to human emotions? Or is it ridiculous to assume that they AREN'T feeling something like that? We get the story of a rescued whale that may have found a way to say thanks, ask whether dogs feel guilt, and wonder if a successful predator may have fallen in love with a photographer.

In tape five, three stories: first, a tale of how the cassette tape supercharged the self-help industry. Second, cassettes filled with history make an epic journey across Africa with a group of Lost Boys. And finally, Simon meets up with fellow Radiolabber David Gebel to dig through an old box of mixtapes and rediscover the unique power of these bygone love letters.

Mixtape was reported, produced, scored and sound designed by me, Simon Adler, with music throughout by me. Unending reporting and production assistance was provided by Eli Cohen.

Special Thanks to: Shad Helmstetter, Vic Conan, Glenna Salisbury, Jerry Rosen, Richard Petty, Sharon Arkin, Angela Impey, William Mulwill for sharing his cassettes with me, and to the British library for sharing some of their recordings from their South Sudan collection, which is housed at the British Library Sound Archive.

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