Antik okyanus kimyası oksijenin kalıcı olmasına yardım etti

Earth’s atmosphere first gained lasting oxygen about 2.3 billion years ago, but scientists have struggled to explain how oxygen remained available long enough to support increasingly complex life. A study involving UC Riverside proposes a feedback cycle driven by ancient ocean chemistry. As oxygen entered seawater, sulfate levels rose. Microbes then used sulfate to break down organic matter more efficiently, releasing phosphorus that had been bound in the system. This recycled nutrient stimulated fresh biological growth. When more organic carbon from that growth was buried rather than decomposed, additional oxygen accumulated in the atmosphere. Researchers tested the idea by analysing South African rocks with a method that separates phosphorus according to the minerals carrying it, revealing how much was biologically available instead of merely measuring the total. The findings also indicate substantial oxygen fluctuations after the Great Oxidation Event and suggest that nutrients, oxygen and life evolved through closely connected processes.