Earth’s Oxygen Rise Helps Search for Life

By analyzing the oxygen content of ancient, iron-rich sedimentary rocks, scientists determined just how low oxygen levels were before life began to flourish.

IMAGE: Ironstones deposited on the seafloor nearly two billion years ago now occur as rocky outcrops along the lakeshore of Tu Nedhé (Northwest Territories, Canada). CREDIT: Devon Cole

A lot of times in science, to understand where you are and what will be, you have to look back at where you came from. In the search…