Let's take a look at motion, nice smooth mechanical motion. These videos provide some insight into how simple principals can be built up into very sophisticated motion. The simplest motion mechanism that humans first developed (the wheel) is the one that most mechanical motion is built upon, yet as the level of complexity in these mechanisms increases, we start to get organic motion that very closely mimics nature. Nature doesn't use wheels much, pivots, fulcrums or centrifugal forces yes, but actual spinning wheels? That's man's invention, and look what we can do with it.
Gears and cables can do a very good job at replicating human and animal type motion, even if it's just at a surface level.