Slime Has Memory but No Brain
The living slime that may have been the muse for the 1958 science-fiction film The Blob just got creepier: Evidence has emerged that slime mold, a brainless single-celled organism, has a form of memory. In experiments with the slime mold Physarum polycephalum, scientists at the University of Sydney noticed that the life-form avoided retracing its own paths. They began to suspect that the slime was using “externalized spatial memory” to navigate.
The team’s current research also suggests that Physarum can recognize and react to the trails left by other species of slime mold. Biologist Chris Reid said externalized spatial memory could have been used by primitive organisms to solve the same types of problems our brains confront today—the start of the evolution of memory. The researchers published their work online in the journal Proceedings of the National Academies of Science.