Did Changes to 3 Genes Cause Ape Hips to Evolve into Human Ones?

This should come as no surprise: Humans and apes have different hips.

The human pelvis is rounded, like a basket, to enable us to walk and stand upright with ease. The ape pelvis is tall and narrow, with the upper hip bones appearing like blades, allowing apes to walk on all fours and effortlessly climb and swing in trees.

In the evolutionary story, we evolved from an apelike ancestor who would have had more apelike hips. How, exactly, this massive anatomical feat of evolution supposedly happened...