Do animals control earth's oxygen level?
Phys.org - Tue 10 Sep 17:51 GMT

No more than 540 million years ago there was a huge boom in the diversity of animals on Earth. The first larger animals evolved in what is today known as the Cambrian explosion. In the time that followed, the animals evolved and grew larger, but concurrently …

  In a new scientific study, researchers from the GLOBE Institute at the Faculty of Health and Medical Sciences, University of Copenhagen, have now found that the animals themselves probably contributed to an adjustment of the oxygen level and thus indirectly controlled their own development.

  We have found that it is not just the environment and the oxygen level that affect the animals, but that, most likely, the animals affect the oxygen level," says Associate Professor Tais Wittchen Dahl from the GLOBE Institute.

  To understand what controls the oxygen level on Earth, the researchers have looked at limestone deposited on the ocean floor during the Cambrian explosion 540-520 million years ago.

  "In this way, the mud burrowing animals themselves helped control the oxygen level and slow down the otherwise explosive evolution of life.

  As it is not possible to test how you might influence the global oxygen level today, scientists must instead resort to the past to gain an understanding of the dynamics that make up Earth's heartbeat—and in this way perhaps make it a little easier to understand life on our own and on other planets.

  information: Tais W. Dahl et al, Atmosphere–ocean oxygen and productivity dynamics during early animal radiations, Proceedings of the National Academy of Sciences (2019).

  DOI: Citation: Do animals control earth's oxygen level?