Today, many scientists think that the evolution of life is related to the amount of oxygen actually available in the atmosphere. The evidence found that this caused the sudden and catastrophic mass extinction of microorganisms about two billion years ago was even worse than the dinosaur extinction event.
However, while oxygen overload theory has become more common in recent years, new research suggests it may actually be wrong.
Analysts on ancient sedimentary rocks have shown that for millions of years after GOE, conditions on Earth were unsuitable for the continued development of complex life.
The evidence comes from new drill cores in Russia’s Northwest Lake Onega area. Here, researchers have discovered ancient shungite, a shiny black mineral, dating back 2 billion years. Constructed almost exclusively of carbon, this shiny slate is one of the best archives.
Researchers often understand that the increase in oxygen over 2 billion years ago led to a change in the carbon isotope in sedimentary rocks, called the Lomagundi – Jatuli Incident (LJE). This suggests that large amounts of organic matter were buried in ocean sediments, resulting in the release of excess oxygen.
But in these shungite rock cores, depositing right after the end of the LJE, researchers found traces of molybdenum, uranium and rhenium, which are extremely high and these are metals often associated with abundant oxygen.
In fact, the concentrations the researchers discovered could not be compared to any other points known in early Earth’s history, almost equal to the most organic modern marine sediments. .
If shungite is deposited, there must simply be enough oxygen around. The authors argue that this conclusion is bound to reevaluate our basic view of the turbulent times of Earth’s history.
Recent discoveries have also found fossils that are about 2.1 billion years old, during a time when it was thought to be a sharp reduction in available oxygen, although the results are still controversial.
Of course, even if the new research findings are true, this does not mean that oxygen levels never fall. Instead, it is related to the oceans on our planet that still provide oxygen much longer than we thought after GOE.
