Like spider monkeys, our ancestors’ tails helped them stay balanced in trees (Getty Images/iStockphoto) For half a billion years or so, our ancestors sprouted tails. Like fish, they used their tails ...

Humans have many wonderful qualities, but we lack something that’s a common feature among most animals with backbones: a tail. Exactly why that is has been something of a mystery. Tails are useful for ...

For half a billion years or so, our ancestors sprouted tails. As fish, they used their tails to swim through the Cambrian seas. Much later, when they evolved into primates, their tails helped them ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. TOKYO — If you’re prone to tripping or ...

Humanity's ancestors have all had tails, but researchers may have identified the genetic mutation responsible for humans and certain primates losing the appendage, a new study suggests. A group of ...

On rare occasions, humans are born with tails—real functioning tails that can even be “wagged” via voluntary muscles contractions in response to emotional stimuli. Although the birth of a baby with a ...

A highly effective tail is needed in order for a sperm to be able to swim, and for a baby to be conceived. By using cryo-electron tomography, researchers have identified a completely new nanostructure ...

If you've ever wondered why seeing a dog wagging its tail makes you so happy, science might have an answer. Humans' relationship with pooches stretches back to the dawn of civilization, but it has ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Humans have many ...