"[...] What the cells did first was unremarkable: They gathered into a ball, composed of dozens of cells or a few hundred. That kind of behavior was already wel

"[...] What the cells did first was unremarkable: They gathered into a ball, composed of dozens of cells or a few hundred. That kind of behavior was already well known and reflects the tendency of skin cells to make their surface area as small as possible after tissue damage, which helps wounds to heal. [...] But the frog skin cell clusters quickly began to use their cilia for a different purpose: to swim around by beating in coordinated waves. A midline formed on the cluster, “and the cells on one side row to the left and those on the other side row to the right, and this thing takes off. It starts zooming around,” [...]" (There's still more stuff that might also be worth reading in the article.)