I'l start by saying that I'm not a creationist or something like that, I fully support evolutionism and the scientific approach. However, while natural selection can powerfully explain the traits of all current species, it can be hard to understand why if this is the mechanism driving evolution, it has not produced even better organisms. I mean, surely we would be better off if we had eyes also in our back, multiple eyes have evolved in other organisms so why not in us or in many other animals? Or, we would be better off if we could dive in the water for a long time as cetaceans do. Or if we had echolocation. Or if we could see well in the dark as other animals do. Or if we had the smell of dogs. Or if we could survive under a wider range of ambient temperatures as many other animals do. And so on (I will not go to the extreme of "and if we could fly"). I am putting these examples from a human perspective to be more clear but the argument is general, given that many advantageous traits have evolved in many animals, it is somehow strange that these have not evolved in many other species, when they would surely mean also a benefit to them. It seems that organisms have evolved just a few advantageous traits, and that "few" is a different set for each species. It seems strange that no organism has harnessed most (or a lot) of the best mutations but each species has only a few of them. Humans have developed intelligence and the ability to manipulate things with our hands but have not developed many of the advantageous traits found in other species. If mutations are really random, it is hard to understand why a mutation for, say, being able to see a wider spectrum of electromagnetic radiation than our visible light spectrum has never happened to the human ancestors as it did in other species. Because if it ever did, it should have provided a survival advantage to its possessor and should have therefore stayed in time.