Purple sock-looking, deep sea creature reveals details about early life

A deep-sea creature that resembles a purple sock has been identified as resembling an early form of life, according to findings published this week in the journal Nature.

The Xenoturbella has no brain, gills, eyes, or reproductive organs. Food goes in and waste goes out through the same opening.

For decades, scientists thought the Xenoturbella had evolved from more complex organisms, but four new species of the creature were found at the bottom of the Pacific Ocean 12 years ago.

That allowed scientists to do extensive genetic testing and discovered that Xenoturbella did not start out as a complex creature -- but had always been simple.

Biologists said the discovery helps them understand how animals have evolved over time.