Read an Excerpt
The Physical Body, The Spiritual Body
Physical and Spiritual Bodies Compared
By Ainsley Chalmers Balboa Press
Copyright © 2016 Ainsley Chalmers
All rights reserved.
ISBN: 978-1-5043-0496-2
CHAPTER 1
GENES
(a). Scientific aspects
Before launching into this complex section, certain definitions need to be established, because science is a language all its own.
Molecules are chemical substances such as methane (CH4), one carbon atom combined with four hydrogen atoms. Sugar (C6H12O6) is another molecule comprising carbon, hydrogen, and oxygen atoms. Common salt (NaCl) is a molecule comprising sodium (Na) and chlorine (Cl) atoms. Polyvinyl chloride plastic or PVC comprises many hundreds of molecules of vinyl chloride (CH2CH-Cl) joined together chemically. Because it has many repeating units of vinyl chloride, it is called a polymer.
Deoxyribonucleic acid or DNA is the genetic material of our cells. It is a polymer located mostly in the nucleus of our cells. It is an information molecule that determines who we are. For example, DNA gives information for brown or blue eyes, shortness or height, our weight, the colour of our hair, the shape of our mouths, the size of our ears, and many hundreds of other characteristics.
DNA is described as a double helix because it looks like two strands of rope wound around each other. This rope strand of DNA is, for functional reasons, divided into smaller pieces called chromosomes.
The information in DNA canbe likened to the information in a book, except the information in the DNA book is made up of only four letters — A, C, G, and T — that follow a specific order. These letters represent four different chemicals whose specific combinations work like a code, the genetic code, to describe us. The information in our DNA book directs our physical characteristics by prompting the body to make different proteins in varying amounts.
There are forty-six volumes compromising the human DNA book. Each volume can be thought of as a chromosome, with the chapters being analogous to genes. Our cells have forty-six chromosomes, twenty-two from Dad and twenty-two from Mum. In addition, we each have an X volume from Mum, and another X volume from Dad (for a female child) or a Y volume (for a male child). Mum's ovum has twenty-two chromosomes plus an X, and Dad's sperm has twenty-two chromosomes plus either an X or a Y.
Our physical characteristics are a mixture of Dad's and Mum's genes, so we usually look like our parents. For example, we may have Dad's nose and ears, Mum's eyes and hair, and so on.
Returning to the book analogy, Dad's chromosome/volume 1 pairs with Mum's equivalent volume 1, his 2 with her 2, and so on. Sometimes, therefore, we are said to have twenty-three chromosome pairs (including the sex-determining X and Y chromosomes). Some animals have more, but most animals have fewer chromosomes than humans.
Cells called parent cells divide to create two daughter cells. When the cell divides, the forty-six chromosomes have to be duplicated so the parent cell can hand down a complete set to each of the two daughter cells. Nearly all cells in the human body contain these chromosomes intact. (A few exceptions, like the red blood cells and platelets, have no DNA.) The chromosomes are identical in every tissue in our body, be it heart, lung, kidney, or muscle.
So how does this information in our DNA make us who we are? Basically, some chapters in our DNA books code for protein. For example, some chapters, or genes, make more of a given protein, resulting in a profound effect on our eye shape. Other genes do not make proteins, but can control genes that do make proteins.
The DNA information of all human beings is almost the same. The differences between us are probably due to less than 10 per cent of all the information in DNA.
Close relatives who intermarry may have children with deformities. This is because they may both have mutations passed down from a shared ancestor, such as the same grandfather. When two people are unrelated genetically, then a bad gene in one will more often be compensated for by a good gene in the other. Typically, healthy children will result.
The DNA content of a bacterium is shorter than ours. A bacterium has information equivalent to a DNA book 100 pages long, comprising three million ACGT letters. In comparison, the information in human cells is forty-six books containing 100,000 pages, comprising over three billion letters. So for a bacterium to evolve into a human, it must increase its information by a thousandfold, from three million to three billion letters.
It must be emphasised that the ACGT alphabet in DNA cannot give information unless it is ordered, just as the letters A to Z in our alphabet must be ordered into units we call words to convey information. To use another analogy, just as your computer is useless unless it has been programmed to do certain tasks, so must the ACGT in DNA must be ordered in a particular sequence to give life. This ordering can be likened to software. Ordering requires intelligence, just as software must be written by an intelligence — a programmer.
(b) Mutations explained
All DNA, in the course of an organism's life, develops errors. As a parent cell copies DNA to make new daughter cells, sometimes spelling errors creep in. There may be the omission of a letter, word, or sentence, or the addition of a letter, word, or sentence. These changes are termed mutations, and can change the intended meaning of a gene. For example, the sentence "The cat is black" could be changed to "The cat is back." Mutations might jumble the order of ACGT to give nonsense messages, just as jumbling up the letters in this book would create nonsense words.
Errors can be made when the gene is copied for the daughter cells, or they may happen in the normal lifespan of one cell. In addition, pollutants in our world can corrupt DNA information.
Copying errors in adult cells are called somatic mutations. Many times these mutations are present in the germ cells (female egg or male sperm) and therefore are inherited at conception. Such mutations are called germ cell mutations. There are over six thousand germ cell mutations reported for humans.
Mutations to DNA information can result in many undesirable effects, such as aging, diseases, and cancer. The reason we age is because our cells mutate.
To counteract damage to DNA information, we have protein enzymes that can repair DNA. They are called DNA repair enzymes. The repair system cuts out a mutated letter of DNA and replaces it with a new, undamaged letter identical to the original, undamaged DNA. Over the course of time, however, the repair system cannot keep pace with the repair required, and we accumulate more mutations in our DNA.
The evidence for mutation accumulation over time has been detected in the laboratory. These accumulated mutations result in breakdown of our body systems as we age, until it is so extensive that we die. So mutations eventually result in disease and death.
People with deficient DNA repair systems age very rapidly. Some develop cancer at a young age. Cancers are caused by mutations to DNA in certain key genes. When DNA is damaged, the cell should detect this damage and produce an appropriate protein from the tumour suppressor gene. This protein stops the cell from replicating, or forming daughter cells, until the damaged DNA is repaired.
If the tumour suppressor protein is not made, or if the gene that instructs the body to create that protein describes a mutated protein, then no suppression occurs. The damaged cell continues to divide, increasing the number of bad (mutated) cells in the body. This cluster of bad cells may eventually become a tumour.
On our cells, there are receptors that are acted upon by outside hormones to increase or decrease cell division. Receptors are also susceptible to mutation. If, as a result of receptor mutation, the cell loses its hormonal brake on growth and continues to divide, the cell will likewise accumulate further DNA damage and can become a tumour.
Certain viruses can insert their genes into ours, causing our genes to mutate and thereby turn our normal cells into malignant cells. Cervical cancer is one example of this. One can now be immunised against this particular group of cancer-causing viruses (called human papillomavirus, or HPV) and thereby be protected from cervical cancer.
To summarise, genes give information that determines the structure and therefore the function of proteins, which in turn determine our physical characteristics. Genes can be damaged, resulting in damaged, non-functional proteins or no proteins. This damage is termed mutation.
(c). Gene function
The human genome has now been sequenced. Each cell has been shown to contain about 30,000 genes that code for about as many proteins. The incredible thing is that all this information is contained in a single cell, smaller than a full stop. In this day and age of miniaturisation, a cell makes the most sophisticated computer look quite large and cumbersome.
Not all the genes in a cell are actively making protein all the time. For example, if one stops eating glucose for a few weeks, then the gene-derived proteins involved in metabolising glucose will be reduced, simply because they are not needed as much. If one starts eating glucose again, then these proteins will be turned on again.
Similarly, if we reduce our overall sugar intake by fasting, the body adapts by metabolising fat stores more efficiently to meet energy requirements. It does this by making protein enzymes actively involved in fat metabolism.
In some cell types, certain genes or proteins are turned on or expressed, whereas in other cells they are permanently turned off, even though the same genes are present in all cells of the body. For example, cells involved in fighting infection (called lymphocytes) activate their genes to produce antibody proteins to neutralise infections. In contrast, muscle cells, which are not involved directly in fighting infection, have these antibody-forming genes, but they are permanently turned off. Muscle tissue rarely, if ever, makes antibodies.
Each cell in the body makes only those proteins related to its role in the body. Where a given protein is not required for normal function, that protein is not made. This makes good sense: why make something when or where you do not need it? Control genes determine the activity of other genes involved in protein synthesis.
Great tracts of DNA do not appear to have any function, in that they do not code for proteins. These apparently useless genes, once called called "junk DNA," account for over 90 per cent of the information in a cell. These bits have recently been shown to have roles that are very likely to be important to the normal function of the cell.
Some of the junk DNA is believed to be like a dimmer switch on a lamp. The dimmer the lamp, the less protein is made. This junk DNA acts like a control gene.
There are DNA segments called pseudogenes that look like normal genes, but do not make proteins. Pseudogenes were thought to be a useless remnant of evolution, genes rendered non-functional by mutations. However, research a few years ago has shown that pseudogenes make products that likewise control the synthesis of certain proteins.
In time, it is very likely that all junk DNA will be shown to have other important roles. Scientists no longer call it junk, as it has demonstrated its importance for normal cell function.
What happens when you have changes or mutations to DNA? If the protein is an enzyme, then its enzymic activity can be unchanged, increased, decreased, or removed altogether. The latter two effects usually occur; that is, the enzymic activity is reduced or deleted.
(d). Chemicals causing mutations.
What are some of the pollutants that can interact with DNA and cause mutations? Among these mutagenic chemicals are 3,4-benzopyrene in cigarette smoke and other combustion products, aflatoxins and nitrosamines in food, chromium and nickel as used in the electroplating, and asbestos and radium as used in the mining industries.
Our bodies produce some pollutants, which are called free radicals. They are generated from normal metabolism. The two most prominent free radicals are superoxide anion and hydrogen peroxide. Free radicals can also damage our DNA. Antioxidants in our cells neutralise free radicals, thereby reducing damage. Some of these are ascorbate (vitamin C), vitamin E, vitamin A, coenzyme Q10, and glutathione. Free radicals are not altogether bad, however, as many have a role in fighting infections.
It is probably true to say that most mutations are caused by pollution, whether in the environment or in our bodies as free radicals. One of the most devastating effects of mutations is the formation of cancerous cells, and the estimate by reputable cancer agencies is that up to 90 per cent of cancers are caused by pollution. You are no doubt aware that cigarette smoking greatly increases the risk of lung cancer. The Japanese who survived the atomic bombs dropped on their cities in World War II had a much greater incidence of blood-related cancers, such as leukaemia and lymphoma. Similarly, those who survived the Chernobyl nuclear disaster are expected to have an increased tendency to form cancers.
This is a very depressing scenario. But we are all "polluted" in this sense, and thereby mutated in our genes to a greater or lesser extent. In short, we are all mutants.
(e). How mutations cause cancer
There is a better understanding now of how mutations cause cancer, though the fine details are still being researched. It is known that we have in our chromosomes lengths of DNA which are known as proto-oncogenes. These genes are under strict control in the cell and are usually expressed when the cell divides. Some proto-oncogenes act as growth factors, regulating the growth of the cell. Other genes called anti-oncogenes, or tumour suppressor genes, slow down cell division in order to permit DNA repair to occur. Anti-oncogenes therefore reduce or inhibit the formation of mutations.
If mutations occur in the DNA of proto-oncogenes or antioncogenes, the genes produce mutated proteins that inhibit normal controls for cell growth or DNA repair. When this mutation event occurs, the cell as a whole can turn into a cancer cell.
Proto-oncogenes, when mutated, are called oncogenes, and it is the oncogene that changes a normal cell into a cancerous one. Mutated anti-oncogenes do not become oncogenes, but their defect means that norml DNA repair is not occurring. This promotes the development of the cancer cell, though it does not cause that development.
In the normal human cell, there are about a dozen proto-oncogenes and anti-oncogenes, most of which, if mutated, can generate cancers.
Viruses can also generate cancer, as we have touched on already. Another well-known virus that acts by a similar mechanism is called HIV-1 or human immunodeficiency virus type 1. This virus is responsible for the disease called acquired immune deficiency syndrome or AIDS. It also has an effect of increasing the incidence of a specific cancer called Kaposi sarcoma.
HIV is attracted mostly to a particular white blood cell type called the T-helper cell, which has a central role in defending the body against invading organisms such as bacteria, viruses, and fungal infections. Once inside the cell, HIV inserts its genes into our genes. It then makes many copies of itself so that it can infect other cells similarly. This process of replication results in the death of the host T-helper cell and spreads of millions of HIV virions to neighbouring T-helper cells. The death of the T-helper cells puts AIDS patients at the mercy of the multitudes of disease-causing microorganisms which are continually waiting to get at all of us, but are normally neutralised by a healthy, functioning immune system.
Spiritual aspects of genes
The Bible has much to say about family trees, especially the one relating to Our Lord Jesus Christ. In Christ's family tree were many famous yet fallible people, such as Adam, Seth, Noah, Abraham, Israel, and David. To my way of thinking, this chapter on genes has two important implications as far as the Bible is concerned, and these are considerations of evolution and salvation.
(a) Initial difficulties
At one time I was a new Christian and staunch evolutionist (termed a theistic evolutionist). Comments by some well-meaning Christians that evolution was against what the Bible said about creation made me feel uncomfortable. I tolerated these simplistic comments by saying that these people were not scientists and therefore did not fully understand the evolution story. Also, some Christian ministers agreed with me that the evolution story could be reconciled with Genesis 1. I viewed evolution as God's plan for creating our world and the universe. I bore in mind that evolution is a theory, and that it could possibly be wrong. But until something better came along, I intended to stick by it.
(Continues...)
Excerpted from The Physical Body, The Spiritual Body by Ainsley Chalmers. Copyright © 2016 Ainsley Chalmers. Excerpted by permission of Balboa Press.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
