by John F. McCarthy

137. The question of evolution. At the end of the previous lesson it was noted that, while Catholics should not accept even theistic evolution as a proven fact without seeing how it can fit into the biblical description of the origin of the world and without being aware also of the evidence that exists against the theory, unfortunately, most Catholics seldom take the time to study the evidence that exists against it. It was noted also (no. 133) how Pope Pius XII in 1950 declared that those people go too far “who act as if the origin of the human body from pre-existing and living matter were already completely certain and proved by the facts” and “as if there were nothing in the sources of divine revelation which demands the greatest moderation and caution in this question” (Humani generis, nos. 35-36), while Pope John Paul II added in his 1996 Message to the Pontifical Academy of Science that those theories of evolution that regard the spirit (soul) of man as having simply emerged from the forces of matter “are incompatible with the truth about man” Hence, it might be useful to consider here whether evolution has in the meanwhile become a scientif­ically proven theory.

138. Arguments for the theory of evolution. The theory of evolution is being promoted as a fact of nature in the media and throughout the public educational system. News items featuring evolution frequently appear. A book appealing to Christians to accept as a proven fact the Darwinian theory of evolution, titled The Language of God, was published last year with great media attention by well-known genetic scientist Francis S. Collins, himself a believing non-Catholic Christian. In his book Dr. Collins de­clares that all living organisms have evolved from species to species by means of random change and natural selection without any intervention by God. He presents many arguments to defend his thesis.2

139. The teaching of the Church. Apart from the conditions mentioned in the first paragraph above (no. 137), Pope Pius XII stated also that those inclined to accept evolution as a theory, but not as a proven fact, are obliged to weigh and judge the arguments for and against evolution “with the necessary seriousness, moderation, and measure,” and that they always be prepared to submit to the judgment of the Church (Humani generis, no. 36). This means that those who believe that the theory of evolution is true have an obligation to make themselves acquainted with the arguments proposed against the theory and must also be concerned not to undermine what we have been told by divine rev­elation. To rule out any divine intervention in the rise of living species on earth, including man, would go against divine revelation. Dr. Collins accepts the probable intervention of God in the creation of the first life-form and in the creation of human souls.

140. Some leading arguments against the Darwinian theory of evolution. Everyone who has an opinion regarding the theory of evolution should have seriously considered the following arguments against the theory.3

a) The origin of biological life. Dr. Collins with some evolutionary scientists admits that there is no reasonable explanation from natural causes alone for the rise of biological life on earth, and so he accepts that the first life-form was created by God. This admission makes him a theistic evolutionist, that is, one who admits that not everything on earth or in biological life has come about from purely natural forces. But many other evolutionary scientists and public education in general do not make this admission; they simply ignore the issue in the hope that some day a purely natural explanation will be given for the rise of biological life on earth. The fact is that, from what is now known about the complexity of any living cell, there is no way that life could have emerged by chance. Spontaneous generation was believed in centuries ago, but it was definitively disproved by Louis Pasteur. All life comes from previous life. The spontaneous generation of life cannot be produced in the laboratory, and it has never been observed to happen on earth.

b) The role of chance. Darwinian and neo-Darwinian evolutionists maintain that life-forms emerged on earth over very long periods of time purely by chance from species to species in increasing complexity from a single living cell to the marvelously complex forms that exist today. Those who have calculated the odds maintain that there is absolutely no possibility that this could have happened. They have shown that even for one protein molecule to be formed purely by chance it would take more time than has been calculated for the entire span of the universe (estimated by evolutionists to be about 14.5 billion years). And evolutionists are talking about the forming of everything from simple bacteria to fleas and elephants. Add the fact that the vast majority of mutations that do occur in the genes of living organisms are harmful and tend to be eliminated. Only a very small percentage could serve any useful purpose.

c) No transitional organisms. Millions of fossils of extinct species and of living species have been discovered and studied, but not one transitional form has ever been found. There are fossils of some forms intermediate between more distant species, such as between reptiles and mammals, between reptiles and birds, or between fish and four-legged animals. But these intermediate forms are complete and functional in themselves. There are no fossils of any organisms having organs partly of one species that are on the way to becoming organs of another species. Feathers, for instance, have a highly complicated structure. There are claimed to be a few fossils of a lizard with feathers, but the body of the lizard is completely lizard, and the feathers are fully formed feathers. This organism is complete in itself. Moreover, of the million or so species known to be living on earth today, not one is transitional in the sense of having organs of one species partially changed into organs of another species which would be gradually coming into being. In addition, while different species do have a pattern of resemblance to one another, this resemblance could just as well imply a common designer as it might imply a common ancestor.

d) The gap in the simplest species. Darwinian evolutionists maintain that all living species of animals evolved from a simple one-celled animal. One-celled animal species existed at the beginning and still exist today, but there are no examples of any two-celled to five-celled animals, and all known forms of six-celled to twenty-celled animals are parasites that can live only in more complicated organisms. Therefore, more complicated organisms had already to be in existence before the parasites could live and evolve, and these parasites would have had to jump immediately from a one-celled species to a six-celled species, while the second non-parasitic species would have had to jump from a one-celled species to at least a twenty-one celled species, which is not in keeping with Darwinian theory

e) The metamorphosis of insects. Eighty-seven percent of insect species undergo complete meta­morphosis, that is, they are born as a larva (such as a caterpillar) and then build a cocoon inside of which their body disintegrates into a thick, pulplike liquid, into which the nerves, muscles, eyes, brain, and most other organs of the larva are dissolved. After a certain time, an adult insect emerges, greatly different in structure and behavior. The larva has a chewing mouth, the insect into which it turns has a sucking tube. The larva has no legs; the insect has six segmented legs. The larva is a crawler; the insect can fly. Most important, the larva cannot reproduce, while the insect into which it turns can. Which came first, the larva or the transformed insect? If the larva cannot reproduce, how could it survive over thousands or millions of years in order that it could collect in its descendents enough mutations to form the adult insect? How could the genetic material for both the larva and the adult be collected at the same time in the organism? Finally, why would natural selection allow a process like this to arise?

f) Immune systems. All living organisms of any significant complexity need an immune system to survive against the attacks of bacteria, viruses, and toxins. But the large amount of genetic information controlling each immune system could not have accumulated slowly over a long period of time, because the system has to be complete before it will function, and so every complex species would have been destroyed long before it could have been able to defend itself. Thus, the immune systems did not evolve: they must have been programmed from the beginning.

g) Sexual reproduction. Evolutionists cannot explain how or why sexual reproduction arose. The astoundingly complex, radically different, and yet complementary systems of the male and female counterparts for the vast majority of species would have to have evolved completely and independently for each stage and to have finally emerged at the same time and in the same place. Thus, for a new species to be propagated from the original pair, random evolution would have to provide, at the end of a span of hundreds of thousands or even millions of years, a complete male and a complete female in the same place and at the same time. For instance, the millions of complex products of the male reproductive system would have to have an affinity for and a mechanical, chemical, and electrical compatibility with the eggs of the female re­productive system. How could a chance process hit this mark time and again for over a million species? How could natural selection, which tends to eliminate inconveniences, allow such a system to grow up in all these organisms? Also, the steps by which an embryo becomes either a male or a female are not the same for all animals.

h) Reports of apelike men. Announcements over the years of the discovery of the bones of apelike men have often been greatly exaggerated, to the extent that many have been frauds and hoaxes. This fact has been an embarrassment for empirical scientists. Piltdown man, whose figure was in biology textbooks for forty years, was proved to be a hoax. Java man was a fraud. Rama­pithecus was a mistake. Peking man was a fraud. Nebraska man, whose picture was published in the Illustrated London News in 1922, was drawn on the basis of a single unusual-looking tooth, which soon turned out to be the tooth of an extinct pig. These and other examples should cause any prudent person to be at least suspicious of supposedly scientific reports about human ancestors.

i) Common sense. Whoever steps back and takes a good look at the big picture of biological life on earth can see that every living species is an artistic and engineering master­piece. Darwinian evolutionists have to place their noses very close to the “canvas” to put this fact out of focus and to miss the intelligent design that is in them. Darwinians are mechanists who do not acknowledge in any living organism the presence of a life-principle, a soul, which is ultimately responsible for the growth, structure and activity of the organism. How could these souls have come into existence, if they had not been designed by God? And this is true especially of the human soul, which could not in any case spring from the forces of matter. The Catholic Church teaches that every indiv­idual human soul is directly created by God. But if God intervenes in each case to create billions of human souls, could He not logically have intervened to create at least the idea and the parents of each biological species? But Darwinian evolutionary theory does not allow for this.

141. Theistic evolution. Many Christians believe in the evolution of species with some role played also by God the Creator. Believers like Francis Collins allow that God created the original matter of the universe, but after that let it go on its own. They might also allow that God created the physical laws which then influenced the shaping of the universe. Other Christian evolutionists allow for further divine interventions. One recent variant of the theory is that the evolution of species might have taken place in this way that God inter­vened to modify the DNA as each new species was born. This would mean that the different species arose, not by chance, but by the creative intervention of God. Certainly, this version of the theory is more compatible with Catholic doctrine and tradition, if it can be completely brought into harmony with the teaching of the Church and of Sacred Scripture, but the question still remains of whether the evolution of species from species ever really took place at all.


1. Oblates of Wisdom Study Center, P.O. Box 13230, St. Louis, Missouri 63157.

2 For a more detailed exposition of the material in this lesson, see the article “Francis Collins and The Language of God,” in Living Tradition, numbers 124 and 125 (July and September 2006). Current arguments in favor of the Darwinian theory of evolution are well expressed in Dr. Collins' book and are briefly summarized by me with some selectivity in these two issues of Living Tradition.

3 The following samples of arguments are taken from Walt Brown, In the Beginning (seventh edition). The book is available from Amazon Books and from the publisher: Center for Scientific Creation, 5612 N. 20th Place, Phoenix, Arizona 85016 (telephone: 602-955-7663). Dr. Brown presents many additional arguments in his book.