Rivers, streams, lakes, and reservoirs aren't just scenic parts of our landscape—they're also vital engines for life on Earth. These inland waters "breathe" oxygen, just like we do. But a new study ...

Finding oxygen in an exoplanet’s atmosphere is a clue that life may be at work. On Earth, photosynthetic organisms absorb carbon dioxide, sunlight, and water and produce sugars and starches for energy ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. “I basically told ...

For decades, scientists have believed that complex life began when two very different microbes joined forces, eventually giving rise to plants, animals, and fungi. But one major puzzle remained: how ...

Cyanobacteria, as they still exist today, were the first organisms to carry out photosynthesis and release oxygen. Produced in primeval oceans about 2.5 billion years ago, this oxygen accumulated in ...

Today’s climate change pales in comparison with what happened as Earth gave birth to its oxygen-containing atmosphere billions of years ago. By analyzing clues contained in rocks, scientists at the ...

The most common indication for the administration of supplemental oxygen is acute or chronic hypoxemia. Causes include pulmonary infection, chronic obstructive pulmonary disease (COPD), congestive ...