The curious minds at What If discover what Earth was like 2 billion years ago, exploring early life, atmosphere, and continental formation.

New research suggests complex life on Earth emerged billions of years before previous estimates. The research also suggests ...

Russell has a PhD in the history of medicine, violence, and colonialism. His research has explored topics including ethics, science governance, and medical involvement in violent contexts. Russell has ...

Parts of ancient Earth may have formed continents and recycled crust through subduction far earlier than previously thought.

Oxygen is a vital and constant presence on Earth today. But that hasn't always been the case. It wasn't until around 2.3 ...

The last common ancestor of all living things did not just suddenly appear on Earth roughly 4.2 billion years ago. Some of its genes came from an even older and more mysterious source… "While the last ...

Some of Earth’s earliest microbes evolved the ability to use oxygen hundreds of millions of years before it accumulated in ...

Oxygen is everywhere on Earth today. But that hasn’t always been the case. Scientists think oxygen only became a lasting part ...

Astronomers have announced the discovery of what appears to be an "ice cold Earth," a chilly but potentially habitable rocky ...

The fossils offer a rare glimpse into a cataclysmic event that brought a sudden end to the greatest explosion of life in our planet's history.

Aerobic respiration began hundreds of millions of years earlier than previously thought, a new study suggests.

The Red Planet may have once been half blue. A sea the size of Earth’s Arctic Ocean blanketed part of Mars about three billion years ago, researchers suggest in a study published January 7 in the ...