Evolution was held back two billion years as a result of low oxygen levels during the Earth’s middle ages, according to the findings of a new study, which uncovered a delay in the development of plant life.
In a new paper from the University of Exeter, researchers discuss why oxygen levels were so slow to rise in the aftermath of the ‘Great Oxidation Event,’ when oxygen was introduced into the atmosphere, saying that this dampened growth, in turn, delayed the planet’s evolution.
After the great oxidation, plate tectonics pushed dead organic material that had gathered in sedimentary rocks to the surface. When this material reacted with oxygen in the air, it began consuming it.
The more the oxygen, the quicker this reaction occurred, meaning it was consumed at the same rate at which it was being produced, causing a knock-on effect in the development of plant life.
Using a computer model, the researchers estimate that atmospheric oxygen was probably around 10 percent of present levels.
As more plants developed, however, the more oxygen-producing photosynthesis took place, which in turn slowly reversed this trend, bringing up oxygen levels closer to today’s.