Natural selection does not produce any new information, it only allows for beneficial information that already exists in a species to survive or to be preserved. So the question is, can natural selection working on mutations produce new complex structures.
Evolutionists believe that reptiles evolved into birds. According to Darwinism, the forelimbs of some ancient reptiles gradually evolved into the wing of a bird. The process took millions and millions of years. Allow me to illustrate the process with a story.
Once upon a time, hundreds of millions of years ago, there was a reptile running around that had some mutations which caused it to have offspring to have scales which were elongated on the forelimbs. Those reptiles in turn had baby reptiles which had more mutations that caused the scales to get longer and longer. Those scales were beginning to evolve into early feathers. Over a period of millions of years and tens of thousands of generations this kept occurring further lengthening these scales and eventually becoming a wing.
There is a problem with this story. Can you see it? As these scales were gradually getting longer and longer within a population, pretty soon you've got these scales hanging down several inches off the forearm of the lizard. It cannot yet fly, but now it has a problem because it can't run very well either. So natural selection now prefers the ones without the longer scales and these long scale guys get wiped out. The lizard is not a more fit organism because it has no advantages like flying but it does have many disadvantages. Because it cannot run, it cannot compete against the other animals for food and other resources. Furthermore, it cannot successfully evade its predators.
The wing fails to evolve because its transitional forms were non-viable. A transitional stage is not more fit that what it came from.
It is not just wings and feathers that have to form for flight either. The dense bones of a reptile must reform themselves into lightweight versions for flight too. All these changes are not trivial. Vast amounts of new information in the DNA must come from somewhere.
W.E. Swinton, in Biology and Comparative Physiology of Birds said:
"The origin of birds is largely a matter of deduction. There is no fossil evidence of the stages through which the remarkable change from reptile to bird was achieved."
Some deduction, with no fossil evidence to show for it. Remarkable change indeed. No, make that remarkable God!