Richard Prum says there's a lot that traditional evolutionary biology can't explain. He thinks a neglected hypothesis from Charles Darwin — and insights from contemporary queer theory — hold the answer. Plus: You won't believe what female ducks use for contraception.

• SOURCE:
  • Richard Prum, professor of ornithology, ecology and evolutionary biology at Yale University.

• RESOURCES:
  • "Stop Your Populist Grandstanding Over Wendy’s ‘Surge Pricing’," by Catherine Rampell (The Washington Post, 2024).
  • "Dynamic Pricing Tech May Brighten Retail Bottom Lines and Put Consumers in the Dark," by Kristin Schwab and Sofia Terenzio (Marketplace, 2024).
  • Performance All the Way Down: Genes, Development, and Sexual Difference, by Richard Prum (2023).
  • The Evolution of Beauty: How Darwin's Forgotten Theory of Mate Choice Shapes the Animal World — and Us, by Richard Prum (2017).
  • "Duck Sex and the Patriarchy," by Richard Prum (The New Yorker, 2017).
  • "Dinosaur Feathers Came before Birds and Flight," by Richard Prum and Alan Brush (Scientific American, 2014).
  • "How Chickens Lost Their Penises (And Ducks Kept Theirs)," by Ed Yong (National Geographic, 2013).
  • "Media Attacks Duck Genitalia Research," by Emma Goldberg (Yale Daily News, 2013).
  • "Mate Choice and Sexual Selection: What Have We Learned Since Darwin?" by Adam G. Jones and Nicholas L. Ratterman (PNAS, 2009).
  • "Development and Evolutionary Origin of Feathers," by Richard O. Prum (Journal of Experimental Zoology, 2002).
  • The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe without Design, by Richard Dawkins (1986).
  • "Display Behavior, Foraging Ecology, and Systematics of the Golden-Winged Manakin (Masius chrysopterus)," by Richard Prum and Ann Johnson (The Wilson Bulletin, 1987).
  • The Selfish Gene, by Richard Dawkins (1976).
  • The Descent of Man, and Selection in Relation to Sex, by Charles Darwin (1871).

• EXTRAS:
  • "Is Gynecology the Best Innovation Ever?" by People I (Mostly) Admire (2024).
  • "The Price of Doing Business with John List," by People I (Mostly) Admire (2022).

Thomas Hildebrandt is trying to bring the northern white rhinoceros back from the brink of extinction. The wildlife veterinarian tells Steve about the far-out techniques he employs, why we might see woolly mammoths in the future, and why he was frustrated the day the Berlin Wall came down.

• SOURCES:
  • Thomas Hildebrandt, head of the department of reproduction management at the Leibniz Institute for Zoo and Wildlife Research and professor of wildlife reproduction medicine at the veterinary faculty of the Freie Universität Berlin.

• RESOURCES:
  • "An Inside Look at the Embryo Transplant That May Help Save the Northern White Rhino," by Jeffrey Kluger (TIME, 2024).
  • "Mud, Bugs, and Dung: How Rhinos Shape Their World," by Rinjan Shrestha (World Wildlife Fund, 2022).
  • "The Last Two Northern White Rhinos On Earth," by Sam Anderson (The New York Times Magazine, 2021).
  • "Embryos and Embryonic Stem Cells From the White Rhinoceros," by Thomas B. Hildebrandt, Robert Hermes, Cesare Galli, et al. (Nature Communications, 2018).
  • "Loss of a Species – A Giant, Extinct," by Thomas Hildebrandt (TED, 2017).
  • Colossal.

• EXTRAS:
  • "Why Do We Still Teach People to Calculate?" by People I (Mostly) Admire (2024).
  • "What’s Stopping Us From Curing Rare Diseases?" by Freakonomics, M.D. (2023).
  • "We Can Play God Now," by People I (Mostly) Admire (2022).

She is one of the best basketball players ever. She’s won multiple championships, including five Olympic gold medals and four W.N.B.A. titles. She also helped negotiate a landmark contract for the league’s players. Sue Bird tells Steve Levitt the untold truth about clutch players, her thoughts about the pay gap between male and female athletes, and what it means to be part of the first gay couple in ESPN The Magazine’s Body Issue.

• SOURCE:
  • Sue Bird, former professional basketball player.

• RESOURCES:
  • "‘We’re Betting on Ourselves’: Why WNBA’s Landmark New Deal Is a Huge Win for Women’s Professional Sports," by Percy Allen (The Seattle Times, 2020).
  • "Sue Bird & Megan Rapinoe," (ESPN The Magazine Body Issue, 2018).
  • "Missed Shots at the Free-Throw Line: Analyzing the Determinants of Choking Under Pressure," by Mattie Toma (Journal of Sports Economics, 2015).

• EXTRAS:
  • "Marc Davis Can’t Stop Watching Basketball — But He Doesn’t Care Who Wins," by People I (Mostly) Admire (2021).
  • "The Hidden Side of Sports," series by Freakonomics Radio (2018-19).
  • "The True Story of the Gender Pay Gap," by Freakonomics Radio (2016).