Bacteria are the most diverse organisms on Earth, with a number of species that’s difficult to quantify. They’re also incredibly old. Bacteria consist of a single cell. They do not have bones and are ...

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Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. The story of two of ...

Beneath Earth's surface lies a kingdom of undiscovered microscopic life. These "intraterrestrials" survive in some of the harshest conditions on the planet — and scientists are hunting for these ...