Episode 124 - Snowball Earth

An Earth covered in ice might sound far-fetched, but there’s reason to think it has actually happened in the past – more than once. In this episode, we examine the Snowball Earth hypothesis and the geologic evidence and climate models that back it up, as well as some of the major lingering questions: Just how snowy is the snowball? How could this start? How could it end? And how did life fare on a frozen planet? In the news: ancient tardigrades, meat-eating sloths, shark communities, and relict mangroves. Time markers: Intro & Announcements: 00:00:00 News: 00:04:30 Main discussion, Part 1: 00:32:30 Main discussion, Part 2: 01:02:00 Patron question: 01:44:00 Check out our blog for bonus info and pictures: http://commondescentpodcast.wordpress.com/ Join us on Patreon to support the podcast and enjoy bonus content! https://www.patreon.com/commondescentpodcast  Or make a one-time donation via PayPal: https://tinyurl.com/4c68u4hp Find merch at the Common Descent Store! http://zazzle.com/common_descent Follow and Support us on: Twitter: https://twitter.com/CommonDescentPC Facebook: https://www.facebook.com/commondescentpodcast Instagram: @commondescentpodcast YouTube: https://www.youtube.com/channel/UCePRXHEnZmTGum2r1l2mduw PodBean: https://commondescentpodcast.podbean.com/ iTunes: https://itunes.apple.com/us/podcast/the-common-descent-podcast/id1207586509?mt=2 The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org. Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0/