The most widely accepted scientific explanation for the arrival of all complex life on Earth has had an unsolved mystery at its heart. According to the theory, all plants, animals and fungi, known ...

Ancient microbes tied to our earliest ancestors could use oxygen, reshaping ideas about how complex life began on Earth.

Researchers investigating the origin of complex life on Earth might have just made a major breakthrough. The origin of humanity and the planet Earth is probably debated more than whether the chicken ...

A team led by Brett Baker at the University of Texas at Austin has found that some Asgard archaea, the ancient microbial group most closely related to all complex life on Earth, carried the molecular ...

New genomic research shows some Asgard archaea, ancestors of plants, animals, and fungi, tolerated and used oxygen. The finding supports the idea that complex life arose after oxygen levels surged and ...

For decades, scientists have believed that complex life began when two very different microbes joined forces, eventually ...

In the oceans and on land, scientists are discovering rare, transitional organisms that bridge the gap between Earth’s simplest cells and today’s complex ones.

Learn how oxygen’s early rise could have given complex life the energy boost it needed to evolve.

Complex cells are thought to be the result of a union between two ancient microorganisms, but scientists have long been ...

The first single-celled organisms with a nucleus originated more than a billion years later than biogeochemical evidence had previously indicated. Amoeba are more closely related to humans than to ...