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The evolution of the Earth's first animals more than 500 million years ago caused global warming, according to a new study.
About 520-540 million years ago, animal life evolved in the ocean and began to decompose organic matter on the seabed, resulting in more carbon dioxide and less carbon dioxide. Oxygen in the atmosphere.
The conditions for these early animals became harder as ocean oxygen levels dropped and carbon dioxide caused global warming.
The research, published in Nature Communications comes from the universities of Exeter, Leeds and Antwerp. the Vrije Universiteit Brussel.
"Like worms in a garden, tiny creatures on the bottom disrupt, mix and recycle dead organic matter – a process known as bioturbation," said Professor Tim Lenton of the University of Toronto. # 39; Exeter. "Because the effect of burying animals is so great, you would expect to see big changes in the environment when the entire ocean floor goes from an undisturbed state to a bioturbated state. "
"We have actually seen a decrease in oxygen There are about 520 million years ago, there have been levels in the ocean," said Professor Filip Meysman, of University of Antwerp
"but the rock data showed that the sediments were only slightly disturbed."
the University of Leeds, stated : "This meant that the animals living in the seabed at that time were not very active, and did not move very deep in the seabed." 19659005] "At first glance, these two observations do not appear"
The main author, Dr. Sebastiaan van de Velde, of the Vrije Universiteit Brussel, explained: "The critical factor was to realize that the changes the most important occurred at the lowest levels of animal activity
. "The first bioturbators had a massive impact."
Researchers said this achievement was the "missing piece of the puzzle" ", and allowed them to build a mathematical model of the Earth around this period to look at the changes life forms.
Dr. Benjamin Mills, also of the University of Leeds, who led this part of the research, said: "When we ran our model, we were surprised by what we saw.
" L & # 39, evolution of these small animals in the ocean and the atmosphere, but also increased levels of atmospheric carbon dioxide to such an extent that it caused global warming.
"We knew that warming was occurring at this stage of the Earth's history."
This process has worsened the conditions for these animals, which probably contributed to a number of deaths. Mass extinction events during the first 100 million years of animal evolution
"There is an interesting parallel between the first animals changing world, in a way that was bad for them, and what we humans are now doing for the planet, "said Professor Lenton, director of Exeter's new Global Systems Institute, which aims to develop transformative solutions to the challenges. "We are creating a warmer world with the expansion of ocean anoxia (lack of oxygen) that is bad for us and many other creatures we share the planet with."
Learn more:
What caused the mass extinction of the first animals of the Earth?
More information:
Sebastiaan van de Velde et al., The Anoxia of the Early Paleozoic Ocean and Global Warming Driven by the Evolution of Shallow Burrowers, Nature Communications (2018). DOI: 10.1038 / s41467-018-04973-4
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