The evolution of Earth’s first animals more than 500 million years ago caused global warming, new research shows.
Some 520-540 million years ago, animal life evolved in the ocean and began breaking down organic material on the seafloor, leading to more carbon dioxide and less oxygen in the atmosphere.
In the 100 million years that followed, conditions for these earliest animals became much harsher, as ocean oxygen levels fell and carbon dioxide caused global warming.
The research, published in Nature Communications, is from the Universities of Exeter, Leeds and Antwerp, and the Vrije Universiteit Brussel.
“Like worms in a garden, tiny creatures on the seabed disturb, mix and recycle dead organic material — a process known as bioturbation,” said Professor Tim Lenton, from the University of Exeter.
“Because the effect of animals burrowing is so big, you would expect to see big changes in the environment when the whole…
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