The Medea hypothesis is a term coined by paleontologist Peter Ward for the anti-Gaian hypothesis that multicellular life, understood as a superorganism, is suicidal; in this view microbial-triggered mass extinctions are attempts to return the Earth to the microbial dominated state it has been for most of its history. It is named after the mythological Medea, who killed her own children. Medea represents the Earth, and her children are multicellular life.
Past "suicide attempts" include:
- Methane poisoning, 3.5 billion years ago
- The oxygen catastrophe, 2.7 billion years ago
- Snowball earth, twice, 2.3 billion years ago and 790–630 million years ago
- At least five putative hydrogen sulfide-induced mass extinctions, such as the Great Dying,
- Peter Ward (2009), The Medea Hypothesis: Is Life on Earth Ultimately Self-Destructive?, ISBN 0-691-13075-2
- Gaia's evil twin: Is life its own worst enemy? The New Scientist. Volume 202, Issue 2713, 17 June 2009, pages 28–31 (Cover story)
- Bennett, Drake (2009-01-11). "Dark green: A scientist argues that the natural world isn't benevolent and sustaining: it's bent on self-destruction". Boston.Com. The Boston Globe. Retrieved 2010-02-26.
- Grey, William (February 2010). "Gaia theory – Reflections on life on earth". Australian Review of Public Affairs. University of Sydney. Retrieved 2010-02-26.
- Peter Ward's lecture
- The Medea Hypothesis: A response to the Gaia hypothesis Review of Ward's book, February 12, 2010 .
- Paleontologist Peter Ward’s “Medea hypothesis”: Life is out to get you Scientific American review, January 13, 2010
- The Medea Hypothesis Review by the Astrobiology Society of Britain.
- The Medea Hypothesis: Is Life on Earth Ultimately Self-Destructive? Outlook for the world is still grim Review in the Times Educational Supplement