I have no authority on the subject, but, the fact that we cannot prove nor properly evaluate solutions that emerge from evolution does not change the fact that the first solution that fits is the one that will be kept. Intuitive reasoning that not work on such a subject, but still, I have hard time to accept that it is the best. The only proper qualifier, as you state, is that it is the existing one.
The same way I am not comfortable with using dynamic verbs when describing evolution. Evolution does not find a solution. It's just that a solution that fits emerges. After producing many dysfunctional living individuals. It's still the only way life can evolve by itself, and I wouldn't dare to say if it is a laborious or great way to sustain ifself.
The first solution that fits isn't necessarily kept, unless it can be refined to a high enough level of development to compete with other emerging solutions. The eye, for example, evolved separately many times.
BTW, in human engineering the first solution is also often kept. Look at nuclear power. We probably should be using the thorium cycle, but we kept light water reactors because they were the first big reactor commercialized (for military reasons). Another example would be x86 architecture. I am not arguing that evolution is magical in any way, just that human engineering doesn't show signs of being much better in many cases.
I see a lot of engineers who are ignorant of biology claiming that "evolution is slow" and that we should be able to snap our fingers and do better. It's a popular point of view among the singularity crowd.
Engineers are trained to be arrogant about their abilities. This is probably a good thing, since it causes them to fling themselves at problems fearlessly. But it's also not necessarily realistic.
The same way I am not comfortable with using dynamic verbs when describing evolution. Evolution does not find a solution. It's just that a solution that fits emerges. After producing many dysfunctional living individuals. It's still the only way life can evolve by itself, and I wouldn't dare to say if it is a laborious or great way to sustain ifself.