The simpler an object or system is, the more likely it was designed precisely because it is far easier to do so, and allows for greater precision. Pyramids are one of the simplest shapes, and, although found in nature (as are cubes), spheres are the only perfect shape with regularly turns up (and even then, you regularly have perfect spheres). Greater complexity means greater randomness, and the more complex a system or structure, the more likely randomness played a factor in its generation. If I'm wrong, Doc Stoch will correct me; as his name will tell you, he's an expert on these matters.
The universe isn't as neat and tidy as the anthropists would have us believe. Sure there are laws you can't break or bend, but they still allow for a lot, and serendipity is very much a part of the cosmos.