A species
Many-headed slime mould
Physarum polycephalum
The brainless yellow blob that solves mazes.
You and the many-headed slime mould last shared an ancestor about 1.5 billion years ago (on 23 August, if life's history were one year).
Imagine a bright yellow blob with no brain that can solve a maze. This many-headed slime mould is not a plant, animal or true fungus, even though its name says mould. It is like a giant amoeba, and a distant cousin of fungi and animals.
In a maze with food at two spots, it spreads in all directions, then pulls back from dead ends until one thick tube marks the shortest route between the foods. When scientists placed oat flakes where cities sit around Tokyo, it grew a network similar to the real rail system, balancing short routes with backup paths at low cost.
In cool, damp woods it forms a lacy web of yellow veins a few millimetres thick, usually a few centimetres across. It creeps over rotting leaves and logs, wrapping around and eating bacteria and decaying matter. The feeding blob is a single giant cell, not many cells stuck together.
Stops avoiding bitter
It first avoids bridges coated with a bitter chemical. After crossing many times, it stops avoiding that chemical for a few days and crosses normally.
Pumps itself to move
It squeezes its tubes to pump its insides back and forth, which moves it and carries food around.
From dust to blob and back
Powdery spores hatch into tiny cells that fuse to make the feeding blob. Later the blob forms clusters of tiny balls on stems that release more spores.