# #489 - Four Billion Years of Life on Earth: A Dialogue with Andrew Knoll Page: https://stenobird.com/podcast/converging-dialogues-1498806/489-four-billion-years-of-life-on-earth-a-dialogue-with-andrew-knoll Text version: https://stenobird.com/podcast/converging-dialogues-1498806/489-four-billion-years-of-life-on-earth-a-dialogue-with-andrew-knoll.md Podcast: [Converging Dialogues](https://stenobird.com/podcast/converging-dialogues-1498806) Published: 2026-05-05T03:37:17+00:00 Episode link: https://convergingdialogues.substack.com/p/489-four-billion-years-of-life-on Audio file: https://api.substack.com/feed/podcast/196373884/9b2e9772f80579203b3dd3da54a5a6db.mp3 Processing state: not_requested JSON: https://stenobird.com/v1/public/podcasts/converging-dialogues-1498806/episodes/489-four-billion-years-of-life-on-earth-a-dialogue-with-andrew-knoll Duration seconds: 4274 ## Resource In this episode, Xavier Bonilla has a dialogue with Andrew Knoll about the four billion years of life on earth. They discuss geobiology, carbon and the carbon cycle, nitrogen and phosphorus, sulfur, and metals in the human body. They also talk about plate tectonics, habitability, minerals, climate change, life on other planets, and the future of life on earth. Andrew Knoll is the Fisher Research Professor of Natural History and Earth and Planetary Sciences, Emeritus, at Harvard University. He is the recipient of the International Prize for Biology and the Crafoord Prize in Geosciences and member of the National Academy of Sciences. His books include A Brief History of Earth: Four Billion Years in Eight Chapters and Life on a Young Planet: The First Three Billion Years of Evolution on Earth , and the most recent, Earth and Life: A four billion year conversation . Get full access to Converging Dialogues at convergingdialogues.substack.com/subscribe ## Actions - request_transcript: `POST https://stenobird.com/v1/public/podcasts/converging-dialogues-1498806/episodes/489-four-billion-years-of-life-on-earth-a-dialogue-with-andrew-knoll/transcription-requests` — Idempotently request low-priority transcript generation for this episode. - read_markdown: `GET https://stenobird.com/podcast/converging-dialogues-1498806/489-four-billion-years-of-life-on-earth-a-dialogue-with-andrew-knoll.md` — Read the agent-friendly Markdown representation of this episode resource. A page view does not enqueue transcription. Agents should invoke `request_transcript` explicitly when they need this episode processed. ## Transcript Full transcripts are not published on public pages unless there is a clear rights basis.