Cordially,
Great point, diamond --- highly relevant and easy to understand, which is the best kind of example to present when making an argument. Random mutations, or chance occurrences, tend towards disintegration in our everyday experience.
If evolution has occurred randomly, why in over 3 billion years has life on earth never randomly wandered back over the line between life and no life? Why has the Great Chain of Being been continuous in a random world? Even the late, great Stephen Jay Gould, staunch champion of "chance," admitted that this is a daunting problem in evolutionary theory, which can only be answered --- as he read the theory --- by saying, "We've been lucky."