Scientists are trying to understand how complex life emerged on Earth about 2 billion years ago. Our microbial ancestors could be the key.

Ancient microbes tied to our earliest ancestors could use oxygen, reshaping ideas about how complex life began on Earth.

Learn how oxygen’s early rise could have given complex life the energy boost it needed to evolve.

Scientists have long known that people living at high altitudes, where oxygen levels are low, have lower rates of diabetes ...