From another forum -- why we shouldn't believe in Evolution:


    First of all there is confusing terminology. There are two basic types of evolution spoken of by scientists. The first is micro evolution. Micro evolution posits that organisms change some characteristics  to adapt to conditions. This is an observable phenomenon, and nobody contests that it happens. Macro evolution, on the other hand, posits that all living organisms alive today have descended from a common ancestor (or ancestral gene pool). This process took place as a matter of natural selection, the most fit genetic material surviving to reproduce anew. This is what Darwin taught, and is what most people understand when the term evolution is discussed.

Macro evolution (hereafter referred to as Darwinism) is contrary to faith, which teaches that Man was created by God in His image and likeness, that man is not like the beasts because he has an immortal soul and reason. Darwinism:

1) Was formulated to explain the world around us without needing recourse to God. The ultimate proof of God's existence remains His creation. Evolution is an attempt by atheists to evade this problem.

2) It is not supported in it's conclusions by any scientific evidence.
    a)No current evidence - Given the diversity of life of life on Earth, and given the number of permutations required for an animal to             change into something different enough to be classified a species, evolution would need to be a continuous process. Yet in the time     since Darwin published his theory no one can point to a single new species which has evolved into existence. We have indeed lost         many species, but that doesn't help the theory.
    b)No past evidence - Fossils do not show a direct transitional link between older specimens and current creatures, or even newer          fossils. There are missing links all over the place. No chain, no evolution of the species.
    c) No original evidence - Darwin himself never observed evolution. What he cataloged in his work was differentiation. The difference     is significant. If a breed two types of dog I get a new breed of dog, but I don't get a horse. If I breed a dog and a horse I get nothing.

3) What evidence that does exist tends to contradict it. The fact that mutations in general are usually either stillborn or sterile, the irreducibility complexity of advanced forms of life, and the sheer mathematical improbability of natural selection mitigate against the theory of Darwinism.

4) As a result of point 1, and because of 2 & 3, evolutionists have a religious belief in their theory that borders on fanaticism.

In part of its effort to be "open to the world" (a truly bad idea in the first place), the Church encourages  people to believe in "theistic" evolution, that is evolution that doesn't deny God. However, the mere acceptance of the idea of a common gene pool for life throws into doubt the entirety of Christian belief. If man sprung from the belly of some soulless beast, where is Eden, what of Original Sin? No Original Sin, no redemption. No redemption, then we are in fact animals doomed to cease existence at death. The acceptance of the idea that man is just another variation of animal has directly led to much of the moral decay you see around you today. In the words of John Venari:
"Why is evolution kept alive? Why are we not told that Darwinism is dead? That there is devastating evidence against the theory of evolution? Because ___ if evolution is taken away, practically every major world view of our modern day will have nothing to support it and will come crashing to the ground. Modernism. Communism. Secular Humanism. Eugenics. The New Age Movement and even the atheistic United Nations ___ are all based upon the theory of evolution and could not survive without it. Take evolution away, and it would destroy the entire godless superstructure of our modern world in which all these erroneous ideas and institutions reign supreme."

And in the infallible words of the First Vatican Council:

"If anyone does not confess that the world and all things which are contained in it, both spiritual and material, as regards their whole substance, have been produced by God from nothing- let him be anathema"