I made some comments earlier about anecdotes of engineers not accepting the theory of evolution and natural selection (link) and that got me thinking about the engineering process that is, or closely resembles, evolution.
There is a reason we don’t see a half-crocodile, half-duck (the famous crocoduck) in nature – because those two species had a common ancestor millions of years ago and at that point they parted ways and evolved independently into the current two species. This is analogous to why we don’t see the tail of a Sopwith Camel on an F-16. They both have tails, but the design of aircraft has evolved over the years so the F-16 has a tail that is appropriate for itself, not some older airplane.
And engineering does the same kind of testing before accepting a new feature or process, just like nature. A random change in nature is tested by the environment and if beneficial to the individuals, it is more likely to be retained (a greater percentage of the population survive and breed if they have the change) for future generations and slowly the change becomes part of the species. In engineering, many designs start from a previous, successful design and add such changes that are deemed necessary for the mission, but also that are affordable and have an acceptable risk of failure. If those changes are successful, then they will be the starting point for the next design. Hence moving from the Sopwith to the F-16.