Slime Molds: No Brains, No Feet, No Problem
In a study released last week, computer scientist Selim Akl of Queens University demonstrated that slime mold is fantastically efficient at finding the quickest route to food. When he placed rolled oats over the country’s population centers and a slime mold culture over Toronto, the organism grew its way across the Canadian map, sprouting tentacles that mimicked the Canadian highway system. It’s an experiment that’s been replicated globally several times now — in Japan, the UK, and the United States — all with a similar outcome.
So what is slime mold, and how does it do this?
Slime mold is not a plant or animal. It’s not a fungus, though it sometimes resembles one. Slime mold, in fact, is a soil-dwelling amoeba, a brainless, single-celled organism, often containing multiple nuclei.
Frederick Spiegel, a biology professor at the University of Arkansas and an expert on slime molds, first encountered them nearly 40 years ago. “I thought they were the most beautiful, sublime things I’d ever seen,” he said. “I said, ‘I’ve got to work with these.’”
They come in every color of the rainbow, except — due to lacking chlorophyll — a true green, according to Steve Stephenson, professor of biology at the University of Arkansas. They form strange and sophisticated shapes - some resemble honeycomb lattices, others blackberries. And then there’s the slime mold known as “dog vomit,” because it looks just like the stuff. Some remain microscopic, and others grow rogue, forming bulbous masses, as long as 10 to 13 feet. Yet humans largely ignore them.
“Very few have been consumed as food. You can’t build a house with them. They escape our noses most of the time,” Stephenson said.
Still, our world is crawling with them. More than 900 species of slime mold exist, Spiegel said, and they’re found on every continent. Stephenson and his team — the Eumycetozoan Research Project at University of Arkansas — spent years trying to catalog all species of slime mold around the globe from the Arctic Circle to the tip of Chile. Slime molds are particularly fond of forest floors where they break down rotting vegetation, feeding on bacteria, yeast, and fungus.
More beautiful photos of slime molds here. Also, check out this video of slime molds solving a maze. Fascinating stuff.
