ifty years ago, the smartest people alive were terrified the planet would starve. Today, China just posted its lowest birth rate since 1949 — and it's not alone. This week Roger traces the wild swing from 1970s overpopulation panic to 2026's demographic collapse: Paul Ehrlich's Tonight Show tour, the wheat scientist who quietly saved a billion lives, China's one-child policy and its 30-million-man marriage gap, and the sobering fact that no government in history has ever reversed a birth rate once it falls this far. From ancient Rome's plagues to Hungary's tax breaks for mothers, it's a history of nations solving yesterday's problem — right as the next one shows up. History doesn't repeat, but it sure rhymes.