More than 3.5 billion years ago, the Earth was not the hospitable world we know today. The atmosphere lacked oxygen, the seas ...

Deep in some of Earth’s oldest rocks, traces of ancient life still linger, even when every cell has crumbled. You would not see shells, bones, or clear microfossils in these rocks. Instead, you would ...

Researchers uncovered that trace compounds like nickel and urea may have delayed Earth’s oxygenation for millions of years. Experiments mimicking early Earth revealed how their concentrations ...

A drawing of an orange, cloud-covered planet against a black background During the Archean Eon, 4-2.5 billion years ago, Earth likely looked very different than it does today. Its hazy skies may have ...

Sixty-six million years ago a 10-kilometer-wide space rock fell out of the sky over what is now the Yucatán Peninsula in the Gulf of Mexico. When it hit Earth, it blew a Maryland-sized hole in the ...

Introduction : The coherence of history / Stephen Jay Gould -- The planetary setting of prebiotic evolution / Sherwood Chang -- Early environments : constraints and opportunities for early evolution / ...