Most life on Earth can be broadly split into oxygen consumers and oxygen producers.
This delicate balance of givers and takers keeps the concentration of oxygen in our planet's atmosphere around 21 percent. And, yet, that wasn't always the case.In the first few billion years of Earth's existence, oxygen was relatively scarce. Then, out of seemingly nowhere, the diatomic gas suddenly increased.Scientists have pondered these mysteries for years now, and researchers at the Massachusetts Institute of Technology have a new hypothesis.
This oxygen burial would keep the organic material from being more fully oxidized while being broken down by more voracious microbes. As such, the oxygen would have a chance of building up in the water before trickling out into the atmosphere. Then, the ocean can absorb it again, creating a positive feedback loop.geobiologist Gregory Fourier.
When tracing the genetic lineage of this enzyme, the authors found it existed among microbes that evolved before the great oxidation event. As oxygen became more available in the environment, it probably supported the diversification of similar oxidative metabolisms in other microbes."A potentially important positive feedback nevertheless lies in the interaction of oxidized metabolic products with minerals in sedimentary environments."