www.Chiesa has a great post summarizing the Catholic Church’s position on Darwin’s theory of evolution and other competing views of the creation of life on Earth and man. It’s worth the read.
The other delicate point that we must address is the fact that man cannot consider himself as a necessary and natural outcome of evolution. The spiritual element that defines him cannot spring from matter’s potentiality, but requires an ontological leap, a discontinuity that the Magisterium of the Church has always said was at the basis of humankind’s appearance. This element presupposes that God can exert a positive will. Man’s transcendence, Maritain said, occurs through the soul “thanks to God the Creator’s final intervention which He freely makes and which transcends all of material nature’s possibilities.” The spark of intelligence was lighted in one or more hominids when, where and in the ways God willed it. Nature can potentially receive the spirit according to the will of God the Creator, but cannot produce it itself. After all, this is what happens when human beings are engendered setting them apart from animals. Such an affirmation transcends the boundaries of empirical science, something that scientific methods can neither prove nor disprove.