(Note: Please see the pdf version of this article for missing tables and figures)
Editor's Note: This is the second in a series of articles by Dr. Brand. The first can be summarized as follows: Scientists who support evolutionary views believe that the universe is governed by natural law and that God could not perform miracles that are contrary to such law. Since Creation seems supernatural and unscientific to modern man, he is unable to understand the laws or source of power involved. Thus what a scientist may see as a link in the evolutionary process, a creationist on the other hand may see as evidence of the degeneration that has occurred since Creation. However, we have seen that God can interfere with nature without necessarily breaking any natural laws, as illustrated by the Flood, when God altered the normal course of nature.
IN THE natural world we find a wide variety of animals, representing many different types of structures, from one-celled bacteria and protozoa to the most complex animal—man. There are animals with skeletons inside their bodies, and some with skeletons on the outside. Among the tremendous variety of types in the group some lay eggs and some bear live young; some are cold blooded and some are warm-blooded.
Within each group there are in turn many species, each a little different from the others. For example, there are about 1,200 species of rats and mice in the world. Some of those species are so similar that it is difficult to tell them apart, but each one is different in some way, and each species does not normally interbreed with any of the other species.
Zoologists arrange these animals in a standard classification scheme, beginning with the simplest one-celled organisms, and ending with man (Table 1). In this classification system each type of organism is placed next to those most similar to it.
The study of homologies plays an important part in determining which organisms should be classified close together. When two animals have body parts that are alike in their basic anatomy, and develop along the same growth pathways when the animals are embryos, these similar body parts are referred to as homologous parts. Figure 1 compares the bones in the forelimb of a man, a seal, a bat, and a dog. Humans have hands that are very agile for manipulating objects; seals' flippers are useful only for swimming; bats have wings for flying; and dogs' feet are built for fast running. They all look very different, yet they have the same arrangement of bones. Only the proportions of the individual bones, and the type of fleshy covering are different. A bat's wing bears little resemblance to a human hand, and yet the wing membrane is supported by a skeleton that is equivalent to our four fingers, but with very elongated finger bones.
Evidently, God designed the vertebrate limb to be an efficient and adapt able structure, and then used the same basic design for all the vertebrates. Only minor modifications, mainly in proportions and in the type of fleshy covering, were needed to adapt this skeleton to the needs of each animal. These different types of limbs are homologous, indicating that seals, bats, dogs, and men should be classified in the same group of animals.
However, according to the theory of evolution, the fact that these animals have homologous limbs is considered to be evidence that they evolved from common ancestors. It is often believed that they would not have homologous limbs unless they inherited them from common ancestors. But isn't it just as reasonable to believe that God designed them that way? If so, then homologies in anatomy are not really evidence for macroevolution.
There are also homologies in physiology, biochemistry, and embryology. The principles in these fields are the same as for homologies in anatomy. Similarities in physiology, or similar developmental pathways in embryos are often considered to be evidence of evolution from a common ancestor, but they are also what we would expect to see if all life was created by an intelligent Designer. Also in the biochemical structure and functions of cells there are many features that are virtually the same throughout both animal and plant kingdoms. For example, all living things, both plants and animals (excluding some viruses), have chromosomes containing DNA. This DNA contains the genetic code that determines the entire structure and physiology of the organism.
The fact that the basic details of this mechanism are the same in all living things is considered by some to be evidence that they evolved from a common ancestor, but we can also consider it to be evidence that all living things were designed by one intelligent Designer, who used the same exquisitely designed genetic mechanism for all.
The details of the evolutionary concept of the history of life are based largely on these homologies between organisms. All plants and animals are arranged in a classification system that places the simplest ones first, and then the more and more complex organisms on an ascending scale (Table 1). Those who accept the theory of evolution believe that this arrangement is the order in which the animals evolved, from simple to complex. Organisms with the most similarities, or homologies, are placed closest together in the classification system. From this classification scheme phylogenetic trees are constructed. Phylogenetic trees are diagrams representing the presumed evolutionary path ways along which organisms have evolved (Fig. 2).
If we would compare many different types of wheeled vehicles we would find that they also have many homologous parts, and that they can be arranged in a sequence based on these homologies. For example, they all use the principle of the wheel. Most of them also use levers in some way, and several use energy produced by internal combustion of fuel. Using this information, we now can construct a "phylogenetic tree" (Fig. 3) by following the same principles used in making the tree in Figure 2. Does this mean that cars evolved from two-wheeled carts? Of course no one would say that! The different vehicles have homologous parts because they were all designed to operate under the same natural laws. Certain design concepts were used in several different vehicles, and adapted to meet the different functional requirements of each one. They can be arranged in a sequence of simple to complex because they are designed to serve different functions, and thus their structural requirements are quite different. The result is a wide diversity of types, differing in structural complexity, and each is well suited to perform its unique function.
Developing a Consistent Interpretation
When we apply these same principles to living things, we can develop an interpretation that is consistent with both the biological data and the Bible. Each type of animal is precisely adapted to fill a certain niche in the complex web of life. A sponge is "simpler" than a fish be cause a sponge fills a very different place in nature from a fish, and sponges and fish are both exquisitely designed to occupy their unique and different niches. There is a great variety of living things, representing all degrees of complexity, because there are so many different environments and niches, and living things to fit into each one.
Anyone attempting to make a phylogenetic tree that is as accurate as possible will compare not only living animals but also fossils. A biologist or paleontologist will compare all of the types of living and fossil animals in a certain group, and in order to make a phylogenetic tree, he must determine which types evolved from which types.
If we could climb into a machine that would go back in time we could observe what happened and find out directly which animals evolved from which others. But since we can't do that, the researcher who is making the phylogenetic tree believes that all animals have evolved from common ancestors, and his conclusion resembles Figure 4. However, a creationist looking at the same data might construct a phylogenetic tree such as Figure 5, which assumes that the main groups of animals were created, and that evolutionary changes have been limited to small changes within each created group.
How can we determine which of these phylogenetic arrangements is correct? None of the data we have discussed so far can give us a definite answer, be cause all of this evidence can fit either theory. Evidence that can be logically explained by two different theories cannot properly be used as evidence in favor of just one of those theories.
Aside from reliable eyewitness testimony, there is only one type of evidence that has the potential to tell us once and for all whether evolution of the major groups of animals has occurred. That evidence should be found in the arrangement of fossils in the sedimentary rocks. Sedimentary rocks form when sand or mud or other material accumulates in horizontal layers in some type of basin, and later hardens into rock. These layers of sedimentary rock often contain fossils. If the major groups of animals were created we would not expect to find fossil intermediates between these groups. In other words we would expect to find fossil birds, mammals, fish, in sects, and so forth, but no series of fossils halfway between vertebrates and invertebrates, or halfway between insects and annelid worms.
On the other hand, if these animals had evolved from common ancestors it would be reasonable to expect the lowest fossil-bearing layers to contain only simple (mostly one-celled) animals, and succeeding layers to contain increasingly more complex animals. There should also be series of fossils representing many intermediate steps in the evolution of vertebrates from invertebrates, or the evolution of insects and annelid worms from their common ancestor.
Do the fossils provide us with these evidences of evolution of the major groups? Darwin recognized that in his day the expected fossil intermediate forms had not been found. He freely admitted that "the case at present must remain inexplicable; and may be truly urged as a valid argument against the views here entertained" (The Origin of Species, 1859 edition, p. 310).
He felt confident that paleontologists would eventually find the intermediate fossil types that would prove his theory. After more than one hundred years of intensive collecting, the intermediates have not been found.
The distribution of fossils in the lowest rocks is also quite interesting. The oldest rocks, referred to by geologists as the Precambrian, have almost no fossils, even though many of them are sedimentary rocks similar to layers above them. Above the Precambrian rocks is an extensive series of sedimentary layers. Many of these layers contain abundant fossils. Even the first groups of fossil-bearing rocks, the Cambrian and Ordovician, have an abundant and varied assemblage of fossils, representing all of the major phyla of animals, including the vertebrates (e.g. G. G. Simpson, Evolution after Darwin, vol. 1, Sol Tax ed., 1960). But aren't these early fossils simpler animals than those that exist now? The fossil animals do not give us any reason to believe that they are any simpler than animals living today. The fossil animals in each phylum have the same basic characteristics as living animals in the same phylum. For ex ample, trilobites (Figure 6) are one of the most abundant animals in the Cambrian rocks, and trilobites are as complex as other arthropods living today, and have the same characteristics that identify them as arthropods.
Much of the data that we have dis cussed can be logically explained by either creation or evolution, and doesn't prove anything one way or the other. The difference between a creationist and an evolutionist isn't a difference in the scientific data, but a difference in philosophy—a difference in the presuppositions that are accepted as a basis for explaining the data. A creationist accepts the concept of a divine Creator who created life and then told us about it. Most scientists will accept natural law as the only "creator." Either of these philosophies is a faith. They are based on evidence, but neither one can be proved or disproved by science.
But doesn't the lack of fossil inter mediates prove Creation? It certainly is easier to explain by Creation than by evolution, but if someone wants to believe evolution he can probably find an explanation for the lack of intermediates that is satisfying to him, even though it cannot be scientifically tested.
To a person who has not closed his mind to the Biblical Creation account, special Creation can provide a satisfying and convincing alternative to evolution. The evidence fits Creation as well as, and in some cases much better than, it fits evolution. Another real advantage that the creationist has comes from the mes sages brought to us through the Bible writers from the Creator Himself. Many lines of evidence give us confidence in the Word of God, and this combined with the scientific evidence makes a strong case for Creation. "To man's unaided reason, nature's teaching cannot but be contradictory and disappointing. Only in the light of revelation can it read aright. Through faith we understand.' Hebrews 11:3."—Education, p. 134.