Oxygen may have filled Earth's atmosphere hundreds of millions of years earlier than previously thought.
The estimate also comes with a price tag for describing all these Earth species, most of which are still unknown: $364 billion.
Manipulating microbes shows need to redefine life on Earth, again.
Lynn Margulis died on Nov. 22, age 73, succumbing to the fate that will eventually meet us all, the inevitable conclusion of a train of events that, as she identified, was set in motion billions of years ago.
The ice-buried lake has been isolated from the rest of the world for perhaps a half million years. What lives in its waters?
Early life may have formed between a rock and a wet place.
A new theory argues that the first life on Earth got started "between the sheets" -- sheets of flaky mica minerals, that is.
Twenty years ago, Voyager 1 snapped a photograph that yielded an iconic image of Earth.