Billions of years ago, the Earth was a hostile world. Its atmosphere was dominated by carbon dioxide, methane, water vapor and other gases, with virtually no free oxygen. The planet, as we know it today, was not ready to support plants, animals or human life. Yet within this seemingly barren environment emerged the first microorganisms—simple microbial life forms that would forever transform the destiny of our planet.
Among these early pioneers were photosynthetic microbes, particularly cyanobacteria, which harnessed sunlight to convert carbon dioxide and water into organic matter while releasing oxygen as a by-product. Over millions of years, these microscopic organisms gradually removed vast quantities of carbon dioxide from the atmosphere and created the Earth's oxygen reservoir, altering the planet's chemistry and paving the way for the evolution of complex life.