The New York Times, March 13, 2014
If Tim Lenton is right, we all owe sponges a deep debt of gratitude. It may be hard to give much credit to these simple animals, which spend their uneventful lives on the sea floor trapping floating bits of food. But Dr. Lenton, an earth systems scientist at the University of Exeter, suspects that sponges played a crucial role in the rise of the animal kingdom.
Some 700 million years ago, he and his colleagues argue, sponges re-engineered the planet. The sponges unleashed a flood of oxygen into the ocean, which before then had scarcely any oxygen at all. Without that transformation, we might not be on earth today.



