Oceanic sulfate concentrations are widely thought to have reached millimolar levels during the Proterozoic Eon, 2.5 to 0.54 billion years ago. Yet the magnitude of the increase in seawater sulfate ...

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 ...

A study suggests that around 1 billion years ago, photosynthetic primary producers were likely too small to support the development of animal ecosystems. Approximately between 1.8 and 0.8 billion ...

The Proterozoic eon witnessed transformative shifts in Earth’s geochemical cycles, driven by evolving tectonic regimes, redox conditions and mantle processes. The assembly and dispersal of ...

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 ...

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 ...

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 ...