Evolution: Rationality vs. Randomness
By Dr. Gerald Shroeder
Dr. Gerald Schroeder is a former professor of nuclear physics at MIT and member of the U.S. Atomic Energy Commission. He is the author of "Genesis and the Big Bang," "The Science of God," and the recently-published "The Hidden Face of God." (See the Book List for references)
At the basis of the theory of neo-Darwinian evolution lie two basic assumptions: That changes in morphologies are induced by random mutations on the genome; and, that these changes in the morphology of plant or animal make the life form either more or less successful in the competition to survive. It is by the aspect of nature's selection that evolutionists claim to remove the theory of evolution from that of a random process. The selection is in no way random. It is a function of the environment. The randomness however remains as the basic driving force that produces the varied morphologies behind the selection.
Can random mutations produce the evolution of life? That is the question addressed herein.
Because evolution is primarily a study of the history of life, statistical analyses of evolution are plagued by having to assume the many conditions that were extant during those long gone eras. Rates of mutations, the contents of the "original DNA, " the environmental conditions, all effect the rate and direction of the changes in morphology and are all unknowns. One must never ask what the likelihood is that a specific set of mutations will occur to produce a specific animal. This would imply a direction to evolution and basic to all Darwinian theories of evolution is the assumption that evolution has no direction. The induced changes, and hence the new morphologies, are totally random, regardless of the challenges presented by the environment.
With this background, let's look at the process of evolution. Life is in essence a symbiotic combination of proteins (and other structures, but here I'll discuss only the proteins). The history of life teaches us that not all combinations of proteins are viable. At the Cambrian explosion of animal life, 530 million years ago, some 50 phyla (basic body plans) appeared suddenly in the fossil record. Only 30 to 34 survived. The rest perished. Since then no new phyla have evolved. It is no wonder that Scientific American asked whether the mechanism of evolution has changed in a way that prohibits all other body phyla. It is not that the mechanism of evolution has changed. It is our understanding of how evolution functions that must change, change to fit the data presented by the fossil record. To use the word of Harvard professor Stephen Jay Gould, it appears that the flow of life is "channeled" along these 34 basic directions.
Let's look at this channeling and decide whether or not it can be the result of random processes.
Humans and all mammals have some 50,000 genes. That implies we have, as an order of magnitude estimate, some 50,000 proteins. It is estimated that there are some 30 million species of animal life on Earth. If the genomes of all animals produced 50,000 proteins, and no proteins were common among any of the species (a fact we know to be false, but an assumption that makes our calculations favor the random evolutionary assumption), there would be (30 million x 50,000) 1.5 trillion (1.5 x 1012 ) proteins in all life. (The actual number is vastly lower). Now let's consider the likelihood of these viable combinations of proteins forming by chance, recalling that, as the events following the Cambrian explosion taught us, not all combinations of proteins are viable.
Proteins are coils of several hundred amino acids. Take a typical protein to be a chain of 300 amino acids. There are 20 commonly occurring amino acids in life. This means that the number of possible combinations of the amino acids in our model protein is 20300 or in the more usual ten-based system of numbers, 10390 . Nature has the option of choosing among the possible 10390 proteins, the 1.5 x 1012 proteins of which all viable life is composed. Can this have happened by random mutations of the genome? Not if our understanding of statistics is correct. It would be as if nature reached into a grab bag containing a billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion proteins and pulled out the one that worked and then repeated this trick a million million times.
But this impossibility of randomness producing order is not different from the attempt to produce Shakespeare or any meaningful string of letters more than a few words in length by a random letter generator. Gibberish is always the result. This is simply because the number of meaningless letter combinations vastly exceeds the number of meaningful combinations. With life it was and is lethal gibberish.
Nature, molecular biology and the Cambrian explosion of animal life have given us the opportunity to study rigorously the potential for randomness as a source of development in evolution. If the fossil record is an accurate description of the flow of life, then the 34 basic body plans that burst into being at the Cambrian, 530 million years ago, comprise all of animal life till today. The tree of life which envisioned a gradual progression of phyla from simple forms such as sponges, on to more complex life such as worms and then on to shelled creatures such as mollusks has been replaced by the bush of life in which sponges and worms and mollusks and all the other of the 34 phyla appeared simultaneously. Each of these bush lines then developed (evolved) a myriad of variations, but the variations always remained within the basic body plan.
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Among the structures that appeared in the Cambrian were limbs, claws, eyes with optically perfect lenses, intestines. These exploded into being with no underlying hint in the fossil record that they were coming. Below them in the rock strata (i.e., older than them) are fossils of one-celled bacteria, algae, protozoans, and clumps known as the essentially structureless Ediacaran fossils of uncertain identity. How such complexities could form suddenly by random processes is an unanswered question. It is no wonder that Darwin himself, at seven locations in The Origin of Species, urged the reader to ignore the fossil record if he or she wanted to believe his theory. Abrupt morphological changes are contrary to Darwin's oft repeated statement that nature does not make jumps. Darwin based his theory on animal husbandry rather than fossils. If in a few generations of selective breeding a farmer could produce a robust sheep from a skinny one, then, Darwin reasoned, in a few million or billion generations a sponge might evolve into an ape. The fossil record did not then nor does it now support this theory.
The abrupt appearance in the fossil record of new species is so common that the journal Science, the bastion of pure scientific thinking, featured the title, "Did Darwin get it all right?" And answered the question: no. The appearance of wings is a classic example. There is no hint in the fossil record that wings are about to come into existence. And they do, fully formed. We may have to change our concept of evolution to accommodate a reality that the development of life has within it something exotic at work, some process totally unexpected that produces these sudden developments. The change in paradigm would be similar to the era in physics when classical logical Newtonian physics was modified by the totally illogical (illogical by human standards of logic) phenomena observed in quantum physics, including the quantized, stepwise changes in the emission of radiation by a body even as the temperature of the body increases smoothly.
With the advent of molecular biology's ability to discern the structure of proteins and genes, statistical comparison of the similarity of these structures among animals has become possible. The gene that controls the development of the eye is the same in all mammals. That is not surprising. The fossil record implies a common branch for all mammals. But what is surprising, even astounding, is the similarity of the mammal gene the gene that controls the development of eyes in mollusks and the visual systems in worms. The same can be said for the gene that controls the expression of limbs in insects and in humans. In fact so similar is this gene, that pieces of the mammalian gene, when spliced into a fruit fly, will cause a wing to appear on the fly. This would make sense if life's development were described as a tree. But the bush of life means that just above the level of one-celled life, insects and mammals and worms and mollusks separated.
The eye gene has 130 sites. That means there are 20,130 possible combinations of amino acids along those 130 sites. Somehow nature has selected the same combination of amino acids for all visual systems in all animals. That fidelity could not have happened by chance. It must have been pre-programmed in lower forms of life. But those lower forms of life, one-celled, did not have eyes. These data have confounded the classic theory of random, independent evolution producing these convergent structures. So totally unsuspected by classical theories of evolution is this similarity that the most prestigious peer-reviewed scientific journal in the Untied States, Science, reported: "The hypothesis that the eye of the cephalopod [mollusk] has evolved by convergence with vertebrate [human] eye is challenged by our recent findings of the Pax-6 [gene] ... The concept that the eyes of invertebrates have evolved completely independently from the vertebrate eye has to be reexamined."
The significance of this statement must not be lost. We are being asked to reexamine the idea that evolution is a free agent. The convergence, the similarity of these genes, is so great that it could not, it did not, happen by chance random reactions.
The British Natural History Museum in London has an entire wing devoted to the evolution of species. And what evolution do they demonstrate? Pink daisies evolving into blue daisies; small dogs evolving into big dogs; a few species of cichlid fish evolving in a mere few thousand years into a dozen species of cichlid fish. Very impressive. Until you realize that the daisies remained daisies, the dogs remained dogs and the cichlid fish remained cichlid. It is called micro-evolution. This magnificent museum, with all its resources, could not produce a single example of one phylum evolving into another. It is the mechanisms of macro-evolution, the change of one phylum or class of animal into another that has been called into question by these data.
The reality of this explosion of life was discovered long before it was revealed. In 1909, Charles D. Walcott, while searching for fossils in the Canadian Rocky Mountains, came upon a strata of shale near the Burgess Pass, rich in that for which he had been seeking., fossils from the era known as the Cambrian. Over the following four years Walcott collected between 60,000 and 80,000 fossils from the Burgess Shale. These fossils contained representatives from every phylum except one of the phyla that exist today. Walcott recorded his findings meticulously in his notebooks. No new phyla ever evolved after the Cambrian explosion. These fossils could have changed the entire concept of evolution from a tree of life to a bush of life. And they did, but not in 1909. Walcott knew he had discovered something very important. That is why he collected the vast number of samples. But he could not believe that evolution could have occurred in such a burst of life forms, "simultaneously" to use the words of Scientific American. This was totally against the theory of Darwin in which he and his colleagues were steeped. And so Walcott reburied the fossil, all 60,000 of them, this time in the draws of his laboratory. Walcott was the director of the Smithsonian Institute in Washington D.C. It was not until 1985 that they were rediscovered (in the draws of the Smithsonian). Had Walcott wanted, he could have hired a phalanx of graduate students to work on the fossils. But he chose not to rock the boat of evolution. Today fossil representatives of the Cambrian era have been found in China, Africa, the British Isles, Sweden, Greenland. The explosion was worldwide. But before it became proper to discuss the extraordinary nature of the explosion, the data were simply not reported. It is a classic example of cognitive dissonance, but an example for which we have all paid a severe price.
At this point we must ask the question, what has produced the wonders of life that surround us? The answer may be implied by those very surroundings. In that case the medium would be the message!
Dr. Schroeder on the "Age of the Universe"
Dr. Schroeder on "Existence"
article originally appeared at the web site entitled:
Torah and Science