In a major discovery, scientists have found that the gas necessary for life i.e. Oxygen appeared in the Earth’s atmosphere up to 700 million years earlier than previously thought.
The new study has given several indications of late evolution of life.
The researchers from the University of Copenhagen, Denmark, and University of British Columbia, Canada, drew the major conclusion after examining the chemical composition of three-billion-year-old soils from South Africa. These soils are believed to be the oldest soils on Earth. Low concentrations of atmospheric oxygen were present in the soil, scientists say.
It is noteworthy, earlier researches indicated that oxygen began accumulating in the Earth’s atmosphere only about 2.3 billion years ago. This period of oxygen accumulation on Earth is referred to as the Great Oxygenation Event.
“We’ve always known that oxygen production by photosynthesis led to the eventual oxygenation of the atmosphere and the evolution of aerobic life,” said Sean Crowe, co-lead author of the study and an assistant professor in the Departments of Microbiology and Immunology, and Earth, Ocean and Atmospheric Sciences at UBC.
“This study now suggests that the process began very early in Earth’s history, supporting a much greater antiquity for oxygen producing photosynthesis and aerobic life,” said Crowe.
According to the scientists, there was no oxygen in the atmosphere for at least hundreds of millions of years after Earth formed. Today, Earth’s atmosphere has 20 percent oxygen thanks to photosynthetic bacteria that, like trees and other plants, consume carbon dioxide and release oxygen.
The study was published in the journal Nature.