Well, the process by which genes are passed with genetic mutations is random. If you looked backward in time it looks like animals developed fur to warm themselves. In fact, you're just not seeing all the animals who randomly didn't have fur that froze to extinction.
No it isn't. Randomness, complexity, computability and understandability are related but distinct concepts.
Some problems are simple and random, some others are complex and deterministic and you also even get some problems that are are simple to state, deterministic, provably uncomputable, yet still understandable, such as the Wang tiling problem.
Emit a single photon at a piece of glass angled at 45 degrees with two detectors, one behind the glass, the other at 90 degrees to the emitter. Which detector is the photon going to trigger?
