A Brainless Blob That 'Learns' and 'Sleeps' Is on Display at the Paris Zoo

The yellow slime mold known as "the Blob" can solve mazes and remember things, and now it's the first unicellular organism to be on display in a zoo.
October 17, 2019, 2:33pm
A Brainless Blob That 'Learns' and 'Sleeps' Is on Display at the Paris Zoo
Image: Flickr/Bernard Spragg. NZ

Visitors to the Paris Zoological Park may not be awed at first glance by a new exhibit featuring a bright yellow growth on a portion of a tree. But don’t be fooled: the star of the exhibit, a slime mold nicknamed “the Blob,” can solve mazes, help make music, and re-form itself in two minutes after being split in half—all without a brain.

This exhibit marks the first time a unicellular organism has been put on display at a zoo, since most single-celled creatures are too small to see with the naked eye. The Blob, on the other hand, can grow up to several feet in diameter as its nuclei divide inside a single containing cell.


Curators from the Intermountain Herbarium at Utah State University described the slime mold this way: “It is not pretty, unless you like yellow, and it soon gets uglier. The yellow blob turns gray, becomes hard, then breaks down into a brown powder. People complain that the yellow blob looks like dog vomit and that the brown powder stains sidewalks."

Despite the Blob’s surprising traits, the slime mold is not a mystery at all, but rather a model organism that scientists have used since the 1960s to study the cell cycle, development and movement. The Blob’s scientific name is Physarum polycephalum. Its species name, polycephalum, means "many-headed" in Greek because it is essentially a bag of many nuclei, the parts of cells that contain genetic information.

When faced with challenges, the Blob is able to put its many "heads" together to find efficient solutions, even though it doesn't have a brain. Audrey Dussutour, a scientist at the French National Centre for Scientific Research, has conducted research on the Blob’s ability to remember things, and in a sense "learn." When separated from oatmeal, the Blob’s favorite snack, the slime mold learned to cross a bridge filled with a bad-tasting chemical that it normally avoids.

According to an interview Dussutour gave to the National Centre for Scientific Research, the new slime mold exhibit will also feature videos showcasing the Blob’s problem-solving prowess. If presented with two food sources, it will move toward the more nutritious one. It can also solve mazes with food at the end, prompting scientists to study it as a natural urban planner.


Others have harnessed the Blob’s memory to create music. Ed Braund, a lecturer in computing, audio, and music technology at the University of Plymouth, said in an email that systems created by him and others incorporate the slime mold to listen to music and improvise.

“Programming something that has the same abilities on a conventional machine is very time consuming and difficult,” he said. “As the Physarum polycephalum processors are living systems, the way they respond each time is slightly different, which is great for music.”

The Paris Zoo’s slime mold exhibit opens to the public on Saturday and kicks off a month of Blob-themed events. On Saturday, Dussutour will give a talk at the zoo titled “The Blob, A UFO of Biology.” The followers day, gardeners at the zoo will explain how they grow the Blob, and on October 26, the documentary "The Blob, a genius without a brain” will premiere at the Pariscience film festival.

Andrew Adamatzky, the director of the Unconventional Computing Laboratory at the University of the West of England, Bristol, who researches the slime mold, said in an email that visitors to the exhibit should try to place themselves in the mold’s metaphorical shoes.

“They should try to become a slime mould. They should try to imagine what does Physarum 'think', what dreams Physarum sees when it sleeps (yes, growth of slime of pulsative, so it 'sleeps'), and if slime moulds have a sense of humour,” he said. “They might try to invent a joke which sounds funny from the slime mould's point of view.”