Marine Microbiome and Ocean Productivity

Marine microbes produce roughly half of Earth's oxygen, a staggering contribution that overshadows terrestrial forests. Craig Venter's 2004 Global Ocean Sampling Expedition used metagenomics to catalog over 6 million new genes from seawater, proving microbial activity drives global nutrient cycles at a scale previously unimaginable. This discovery outperforms #5 in demonstrating that invisible life, not plants alone, sustains planetary oxygen levels.