Scientists have long sought to explain a key mismatch in Earth's early history: oxygen-producing photosynthesis evolved hundreds of millions of years before atmospheric oxygen began to rise during the Great Oxidation Event. This delay has been linked to limited phosphorus—a nutrient essential to l ife—but the specific processes controlling phosphorus availability in the iron-rich oceans of Archean Earth (approximately 3.2–2.5 billion years ago) remained unclear. ...read more read less