Solving the Problems of Locomotion

[From Bruce Gregory (2000.0904.1511)]

My grandniece is almost two. She never learned to crawl. Instead, she
propelled herself across the floor sitting upright by throwing her arms and
legs out explosively and scooting her butt forward. This technique allowed
to move across the floor at a reasonable clip. At some point she decided she
wanted to stand upright. As soon as she accomplished this, she began to
walk. For some reason she never fell in the process of mastering walking and
running. There may be some genetic basis for this unorthodox behavior, but I
won't speculate on what it might be!