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'Purple Sock' Found On Sea Floor Could Change Our Understanding Of Animals

No brain. No eyes. No face. This creature performs just three simple functions: eat, shit and reproduce.


Monterey Bay Aquarium Research Institute

Sound familiar?

It should. The intake of nutrients, the excretion of waste and reproduction are among the defining characteristics of life.

What makes this animal different from most others on Earth is that the asexual creature performs each of these tasks through only one hole.

The extremely simple organism is known as the "purple sock" or, scientifically speaking, the Xenoturbella churro, "named for its resemblance to the popular fried-dough pastry."

Scientists recently discovered that much of life on Earth could be descendants of this sock-like creature. While it's certainly not the oldest animal on Earth, scientists involved in the study found out that the Xenotubella genus, of which the "purple sock" is a member, dates back much farther than most animals on Earth today, and has now been placed "near the base of the evolutionary tree of animals."

The recent discovery solves a decades-old mystery dating back to the 1960s when scientists first found the Xenotubella in the oceans off the coast of Sweden. Back then, they wondered where to place the strangely simple creature on the evolutionary map.

Scripps Institution of Oceanography

Initially, it was believed the simple organism was more like a flatworm, and had evolved from much more complex animals. "When Greg [Rouse, the study's lead author,] first spotted the worms gliding through a clam field in Monterey Bay, we jokingly called them purple socks," said scientist Robert Vrijenhoek, a co-author of the study.

Now, scientists see that "purple socks" are so simple is because they are very, very old, and they haven't had much reason to change during all this time.

"By placing Xenoturbella properly in the tree of life we can better understand early animal evolution," said Rouse.

"I have a feeling this is the beginning of a lot more discoveries of these animals around the world." We hope so.