Heather Radke, a reporter and author of 'Butts', teams up with Matt Kielty, Radiolab producer, to dive deep into the fascinating world of the human posterior. They discuss its cultural history and evolutionary significance, revealing how our butts have played a role in what makes us human. The conversation takes a thrilling turn as they explore the 'Man Against Horse' race, showcasing an incredible personal story and the enduring competition between humans and horses in the rocky Arizona desert.