Add Yahoo as a preferred source to see more of our stories on Google. Bacteria dish The Great Oxidation Event (GOE) some 2.4 billion years ago established the oxygen-rich atmosphere that many living ...

Washington, D.C.— The Earth's original atmosphere held very little oxygen. This began to change around 2.4 billion years ago when oxygen levels increased dramatically during what scientists call the ...

The appearance of oxygen in Earth's atmosphere was a turning point in the history of our planet, forever transforming the environment and setting the stage for complex life. This event, known as the ...

A new study suggests that aerobic respiration began hundreds of millions of years before oxygen became abundant in Earth’s ...

The Great Oxygenation Event marked a massive transition in life on Earth, when oxygen became plentiful and organisms suddenly had to adapt. Current conditions in Japanese hot springs give clues as to ...

Aerobic respiration began hundreds of millions of years earlier than previously thought, a new study suggests. Oxygen is a vital and constant presence on Earth today. But that hasn’t always been the ...

Researchers mapped enzyme sequences from several thousand modern species onto an evolutionary tree of life. Their findings suggest that, shortly after cyanobacteria evolved the ability to produce ...