Everything that works in machine is antagonistic pleiotropy. Car brakes stop car from crashing. But using car brakes wears out (damages) brakes. Machines damage themselves via machines normal operation. Also known as wear and tear. To keep machine functioning forever just need to repair machine at rate faster than damage laid down. Damage is defined as structural changes to the machine that impair machine function. Machine can only tolerate finite amount of structural change. Too much structural change stops machine function leading to death.