Medea hypothesis

The Medea hypothesis is a term coined by paleontologist Peter Ward^[1] 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.^{[2][3][4][5][6][7]} 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, 251.4 million years ago

The list does not include the Cretaceous–Paleogene extinction event, since this was, as least partially, externally induced by a meteor impact.

See also

• Fermi paradox

References

External links

• 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