I covered Nine Great Proofs of Evolution. I knew of this one, but never thought it would rise in popularity, and it really hasn't in most textbooks.
Evolution lies exposed in the imperfections that record a history of descent.
But he was serious. An engineer, starting from scratch, could design better limbs in each case. Using this strategy one can minimize the cost of dog food, given some equations describing costs, nutrient values, and perhaps even some numeric flavor values. And remember, the mathematical constraints, even if formulated, were themselves subjectively derived. And consider for a moment a committee designing the perfect or optimum door handle on a car.