Dear Theophilus, 

You mention in your last letter that you would like me to discuss the theory proposed in biology which explains the origin of life and which goes under the name of Theory of Evolution. This is what we are going to do in this letter.

Much rancour has been expended by both sides arguing the validity of the theory of evolution. The many advances that have been made in the study of living systems, particularly in biochemistry, have enabled us to get a more objective evaluation of the validity of the theory of evolution.

In talking about evolution, I am going to refer to Darwinism which represents teachings based on the proposals of Charles Darwin. Those who subscribe to Darwinism accept what may be called naturalism. The heart of this is that there is no agency outside the natural world and therefore the beginning of the world and the beginning of life must be answerable only in terms of what we can observe or propose using physical data.

What does Darwinism basically say? It paints the following picture of how we came to be where we are with life spread over the entire globe. Certain chemicals, through random chemical reactions, came together and these, over a large amount of time, produced complex structures which were capable of reproducing. These chemicals, by coming together and forming more complex molecules gave rise to early primitive cells which eventually resulted in living organisms at a very primitive level. Certain changes occurred in these early organisms through what may be called mutations. Certain chance changes caused certain of the organisms to have an advantage in surviving and these were passed on to their offspring resulting, after many, many years in organisms which were significantly different from those that were there at the beginning. All this eventually led to fairly complex creatures and this culminated in the generation of man. All this occurs through the operation of blind chance. Certain fundamental rules apply. The mechanism that is invoked in Darwinism is natural selection (the fittest survive) operating on variation (changes occur through chance mutations). What evidence is given in support for this wide panorama as to how life began and how the varieties of species arose? The answer to this question is problematical because there is not that much evidence to offer.

One of the pieces of confirming data is the fact that the genetic code is universal and applies in humans as well as in animals, plants, bacteria and all other organisms. By genetic code what is meant is the following. Information has to be passed on so that certain molecules, principally proteins, can be synthesized in living organismsto give chemicals necessary for life giving it the ability to exist and to reproduce itself. Proteins are made up of chains of amino acids and the sequence of amino acids is crucial to the function of a given protein. There are about twenty different types of amino acids and these combine in chains of various lengths, in specific orders, to give the different proteins such as insulin or specific enzymes and so on. How does the body know how to synthesize proteins? This information is locked into the master molecule of the body which is the deoxyribonucleic acid or in short, DNA. The DNA molecule consists of three important parts: the sugar, a phosphate group, and a base. The sugar and phosphate group are the same throughout, but the bases, there are four different ones, vary. Various regions on the DNA are called genes and these are programmed for the synthesis of specific proteins. The information is passed along through molecules which are, for simplicity, called bases, of which there are only four different types, as was mentioned above. Various combinations of three bases groupings can code for different amino acids. Therefore a specific three base code represents a specific amino acid and no other. If this were not the case, then the body would have a very difficult time making the proteins that are necessary for carrying on life. There has to be specificity and it so happens that a specific three base code represents a particular amino acid, and no other, whether in a man or a bird or in a plant. And this is what we mean by a universal genetic code. This is taken as support for the fact that we all come from the same common biological source. Or, stated another way, we all have the same common ancestor. If we were to look at the molecule of hemoglobin in humans and compare it to the molecule of hemoglobin in other species, certain interesting observations come out. Hemoglobin, by the way, is a protein that is used to transport oxygen in blood. The hemoglobin has 146 amino acids in it. If you were to look at the hemoglobin of a chimpanzee, there are only 5 different amino acids in comparison to humans; chickens have 26 differences and frogs, 46 when compared to humans. Thus, the more similar the species are, the more identical are the amino acid sequences, and again, pointing to a common ancestor. Further evidence for evolution is given through physical similarities of physical structures, as for example, a human hand and the hand of a chimpanzee. Thus we can imagine our hands arising from changes in the hands of various creatures that have preceded us. This is further bolstered by referring to fossils. Fossils are remains that have been embedded in certain rocks and which preserve the physical appearance , or some aspects of it, of various organisms. As we dig into the soil, we come across representative organisms that lived at various epochs of time and as mwe dig deeper, we find simpler and simpler strutures because we are going further back in time and from this we can see the gradual development and changes that have brought today's species into existence.

There have been certain experiments which have been carried out and which have been said to give support for believing in the theory of evolution. One of the most famous ones was by a fellow called Stanley Miller. What Miller did was to simulate the atmosphere of the early earth which consisted of methane, ammonia, water, and hydrogen. When these were mixed and an electrical spark was passed through the mixture for a period of a week (as if these molecules were exposed to lightning), several amino acids were isolated. Eventually, others using slightly different techniques showed that all twenty amino acids could be synthesized. This looked very promising because amino acids are the basic building blocks of proteins, the substance of life. But problems and difficulties were not far away. When attempts were made to link the amino acids into proteins under the conditions that would have existed on the early earth, they failed. One of the reasons for this is that the reactions between amino acids are called condensation reactions, meaning that a water molecule is a product for each link made, and having water present interferes and does not permit the reaction to go forward. In over thirty years of experimentation, there has been no success in this area. Although some components necessary for life can be made in the lab, and made fairly easily, any attempts to synthesize life have been totally unsatisfactory.

Others have tried to approach the question of the origin of life through molecules which are called ribonucleic acids or RNA, similar to DNA in certain aspects, but different from DNA in many other ways. RNA molecules can act as catalysts in certain chemical reactions. Catalysts are agents that enable a reaction to occur or speed up the rate of that reaction. Be that as it may, the question still remains - how did RNA molecules come into existence? We have no good answer to this question.

Examples of evolution have been claimed in some situations, the most famous being the competition between dark and light moths. With the coming of the industrial revolution, a large amount of soot was ejected into the atmosphere and this caused trees and other structures to take on a darker hue. As a result, the dark colored moths had a distinct advantage since they blended in with the background better than the light colored moths, which were picked off and eaten by the birds who could spot them more easily. So, after some time, only dark moths should exist as the white ones become extinct and as a result, this is claimed as support for the way evolution works. Unfortunately for the evolutionists, this did not happen and, as the environment became less sooty, the balance between dark and light moths returned as it is much more advantageous for the survival of the species to have both light and dark colored moths. This is not an example of evolution, although it is often so painted. There was no irreversible change here. No new species was formed.

I want to point out two different aspects of evolution which it is important to differentiate. We can have what is called macroevolution and microevolution. Macroevolution is the proposal that new species arise from preceding different species. Microevolution describes changes that occur within a specie. Thus, the bills of certain birds made change with time because of pressures exerted because of hunting advantages or other factors. But, it is still the same species and no crossover to another species has occurred. The evidence for microevolution is definitely stronger than it is for macroevolution, but it is just this concept of macroevolution that is at the heart of Darwinism. The evidence for this is very sparse and what is more troubling, there are no mechanisms proposed which tell us how these changes between species occur. There is no time given scalegiven, there is no detailed description of the various steps except for some imaginative speculation. So you say to yourself: how come the theory of evolution, as espoused by Darwin, has become so powerful and so accepted? The answer to this question comes in the next letter.

Yours, as always,

Bar-Abbas

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