The mystery of muscle memory

The mystery of muscle memory

When the tobacco hornworm has nearly completed its 18-day metamorphosis, it uses a set of powerful abdominal muscles to escape from the confines of its old exoskeleton. In its new life as a tobacco hawkmoth, it doesn't need those oversized abs anymore — so they shrink. Over the course of just three days, the muscles get 40 percent smaller, a loss that's equivalent in human terms to an 80-year-old after three decades of the muscle-wasting conditi…