Genes & Cells

How humans evolved shorter pregnancies, plus crayfish brains and restoring nerve insulation in this week’s news

Walking, thinking crawdad
Researchers have identified a “get ready to walk” signal that lights up in a crayfish’s brain cells as the animal decides to start moving. Katsushi Kagaya and Masakazu Takahata of Hokkaido University in Japan tethered crayfish to the tops of balls.