The ratio of the distance between successive bifurcation values approaches a constant 4.669 as the number of bifurcations increases. This appears to be a universal property of bifurcating maps. Different equations and different mechanisms implementing those equations still show a very general universal property. The emergence of walking is an example of a system that seems to be driven by the successive emergence of different mechanisms, but may be the result of changing dynamics.
Newborn infants produce coordinated stepping movements when held upright.
Movements disappear at about 2 months and reappear at about 8-10 mo. Real walking emerges at about 12 mo. Behavior is sensitive to bodily and environmental parameters. Stepping can be elicited during the silent period if the baby is held upright in a warm bath. Infants perform coordinated alternating steps when held upright on a motorized treadmill.