Scientists have come up with a new idea for how Earth got its oxygen. The theory is, it is because the planet slowed down and days got longer.
A study which was published on August 2, 2021, proposes and puts to the test the theory that longer, continuous daylight kick-started the weird bacteria into producing lots of oxygen, making most of the life on Earth as we know possible.
The scientists dredged up the gooey purple bacteria from a deep sinkhole in Lake Huron and tinkered it with how much light it got in lab experiments. The more continuous light the microbes received, the more oxygen they produced.
Oxygen on Earth: What led to the new theory?
One of the greatest known mysteries in science is just how planet Earth went from a planet with minimal oxygen to the breathable air we have now.
Scientists and experts in the area had long figured microbes called cyanobacteria, were involved in the oxygen growth but were not able to figure out and tell what started the great oxygenation event.
What does the new theory say?Researchers involved in a study in Monday’s Nature Geoscience have theorized that Earth’s slowing rotation, which gradually lengthened the days from 6 hours to the current 24 hours, was key for the microbes or cyanobacteria in making the planet more breathable. About 2.4 billion years ago there was so little oxygen in Earth’s atmosphere that it could hardly be measured, so no plant or animal lifelike, as know now, could have lived. Instead, lots of microbes breathed in the carbon dioxide, and in the case of cyanobacteria, produced oxygen in the earliest forms of photosynthesis. The study’s lead author, Judith Klatt, a biogeochemist at the Max Planck Institute in Germany, said that at first, it wasn’t much, however, in only about 400 million years Earth’s atmosphere went to one-tenth the amount of oxygen we have now, which is a huge jump. That oxygen burst on the planet allowed animals and plants to evolve, with other plants joining in oxygen making. |
What led the bacteria to go on oxygen production?
To answer this, Michigan University’s oceanographer Brian Arbic comes in as he studies the tidal forces on Earth and how they have slowed down the rotation of the planet.
He was listening to a colleague’s lecture about cyanobacteria and noticed that the oxygen event coincided with the timing of the longer days on Earth. The rotation of Earth slows because of the complicated physics of tidal friction and interaction with the moon.
The researchers from Germany and Michigan put their theory to test with bacteria similar to what would have been around 2.4 billion years ago. The scientists used purple and white mats of cyanobacteria living in an eerie world of the sinkhole nearly 79 feet deep in Lake Huron.
Judith Klatt and the colleagues exposed the bacteria, which smelled like rotten eggs, to varying amounts of light, up to 26 straight hours. They discovered that more continuous light caused the microbes to produce more oxygen.
Conclusion |
The authors of the study and the outside scientists stated that this is just one possible but plausible explanation for the oxygen increase on Earth.
Tim Lyons, a professor of Biogeochemistry at the California University, Riverside, who wasn’t part of the research team, said that what makes the current idea so impressive is that it does not require any form of big biological changes in bacteria or the world’s oceans.
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