The giant-impact hypothesis posits that billions of years ago a Mars-sized body named Theia collided with the early Earth.

Tropical riparian ecosystems—those found along rivers and wetlands—recovered much faster than expected following the ...

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Some cyanobacteria have pigments that specialise in harvesting green light to power their photosynthesis, which may be an evolutionary adaptation to a time when the oceans were iron-rich and green-tin ...