One might add that this analysis applies to the world of life as a whole.
The contrast between the evolutionary sterility of Lenski’s unintelligent Darwinian evolution and the evolutionary potency of Arnold, Smith, and Winter’s intelligent evolution is striking.
The design inference is obvious but often implicit, because explicit acknowledgement of design in biology carries with it substantial career risk.
Coming from the National Center for Science Education or the New York Times, this is typical.
In effect, protein engineers are using the power of random change plus intelligent design to see what if anything will improve function.