Advanced tools and expanded fossil datasets have painted a clearer picture of the eukaryotic diversity of the Proterozoic eon, which has been hard to quantify. The findings show that Earth's severe ...

A couple of times in four billion years, evolution has slowed to a crawl. And an eon or so has passed before more complex life forms, such as simple animals, could arise. Evolution may have been ...

The partial pressure of oxygen in Earth's atmosphere has increased dramatically through time, and this increase is thought to have occurred in two rapid steps at both ends of the Proterozoic Eon (~2.5 ...

A single enzyme found in early single-cell life forms could explain why oxygen levels in the atmosphere remained low for half of the Earth’s existence. The discovery could explain why, for two billion ...

Ancient species may have evolved more slowly and lasted longer, but the pace of evolution picked up after global ice ages, according to a new study from Virginia Tech. Published in the journal Science ...

Proceedings of the National Academy of Sciences of the United States of America, Vol. 113, No. 41 (October 11, 2016), pp. 11447-11452 (6 pages) Pervasive anoxia in the subsurface ocean during the ...

Laughing gas and the mystery of Carl Sagan's Faint Young Sun Paradox: When the sun shone dimmer an eon ago, Earth remained warm in spite of it likely thanks to a mix of greenhouse gases.

Artist's impression of the "pale orange dot" - what early Earth would have looked like. Credit: NASA/Goddard Space Flight Center/Francis Reddy Artist's impression of the "pale orange dot" - what early ...

It was long assumed that cyanobacteria were mainly responsible for fixing nitrogen on early Earth, thus making nitrogen available to the biosphere. Researchers now show that purple sulfur bacteria ...

(CN) — More than a billion years ago, tectonic activity on Earth may have stopped so completely that no new mountains could be formed on the planet for an entire eon — putting evolution of life on ...