Scientists studying the origin of Earth's first breathable atmosphere have show how plankton provided a critical link between the atmosphere and chemical isotopes stored in rocks 500 million years ago.
The study builds on the team's earlier discovery that upheavals in Earth's crust initiated a kind of reverse-greenhouse effect 500 million years ago that cooled the world's oceans, spawned giant plankton blooms, and sent a burst of oxygen into the atmosphere.
The new study led by Ohio State University researcher Matthew Saltzman and colleagues has revealed details as to how oxygen came to vanish from Earth's ancient atmosphere during the Cambrian Period, only to return at higher levels than ever before. It also hints at how, after mass extinctions, the returning oxygen allowed enormous amounts of new life to flourish.
I'm OK with this