Did neurons evolve twice?
Cara Giovanetti writes: The human brain’s billions of neurons represent a menagerie of cells that are among both the most highly specialized and variable ones in our bodies. Neurons convert electrical signals to chemical signals, and in humans, their lengths can be so tiny as to span just the tip of a sharpened pencil or, in some cases, even stretch the width of a doorway. Their flexible control of movement and decision-making explains why they are so key to survival…