Evolution is true, in the sense that one particular species can evolve to
adapt better to its surroundings. However, there is no convincing proof
that one species can evolve into another. For example, there is not one
single case of a series of fossils showing the continuous succession of one
species evolving into another. The classic case of the horse skeletons
which showed three species of horse, each different in size, does not prove
that they evolved from one another. The fact that not one skeleton was ever
found to represent a transition between the horse species is not good for
those convinced of evolution.
And natural selection" is a rather silly notion if you define it as nature
selecting those species who are fittest, to survive, because you run into
circular "logic": Which species survive? The fittest. Who are the fittest?
Those who survived. Etc, etc. There is no possible way to prove that the
species on Earth now were in fact the fittest a couple of thousand years
ago. In fact, many biologists who specialise in the evolution of certain
species define "fittest" to mean "those species who produce the most
offspring", which does not at all mean that those species are necessarily
the fittest at all.