Oxygen rise didn’t lead to evolution
[DARWIN IDENTIFIED IT WITHOUT ACKNOWLEDGING THE CREATOR]
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LONDON: Oxygen is crucial for the existence of animals on Earth, but an
increase in the gas did not lead to the rise of the first animals on
our planet, a study has found.
Researchers showed that 1.4 billion years ago there was enough oxygen for animals, yet over 800 million years went by before the first animals appeared on Earth.
The late evolution of animals, and the fact that oxygen is central for respiration, led to the belief that animal evolution corresponded with a late rise in atmospheric oxygen concentrations. "But sufficient oxygen in itself does not seem to be enough for animals to rise," said Emma Hammarlund and Don Canfield from the University of Southern Denmark.
The researchers analysed sediment samples from the Xiamaling Formation in China, which shows that a deep ocean 1.4 billion years ago contained at least 4% of modern oxygen concentrations. The researchers used trace metal distributions to show that the bottom waters contain oxygen. The distribution of biomarkers showed that waters of intermediate depth contain no oxygen.
"Sponges probably resemble some of the first animals on Earth. If they manage with less than 4% of today's oxygen levels, it is likely that the first animals could do with these concentrations or less," Canfield added.
The sudden diversification of animals might have been a result of many factors and the oxygen rise may have had less to do with the animal revolution than previously assumed, researchers said.
Researchers showed that 1.4 billion years ago there was enough oxygen for animals, yet over 800 million years went by before the first animals appeared on Earth.
The late evolution of animals, and the fact that oxygen is central for respiration, led to the belief that animal evolution corresponded with a late rise in atmospheric oxygen concentrations. "But sufficient oxygen in itself does not seem to be enough for animals to rise," said Emma Hammarlund and Don Canfield from the University of Southern Denmark.
The researchers analysed sediment samples from the Xiamaling Formation in China, which shows that a deep ocean 1.4 billion years ago contained at least 4% of modern oxygen concentrations. The researchers used trace metal distributions to show that the bottom waters contain oxygen. The distribution of biomarkers showed that waters of intermediate depth contain no oxygen.
"Sponges probably resemble some of the first animals on Earth. If they manage with less than 4% of today's oxygen levels, it is likely that the first animals could do with these concentrations or less," Canfield added.
The sudden diversification of animals might have been a result of many factors and the oxygen rise may have had less to do with the animal revolution than previously assumed, researchers said.
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