Slave Species of god
Page 3
CHAPTER 2
The Cell
Our human body is truly a miracle of creation. It clearly points to an extraordinary event that led to our existence. Our bodies consist of billions upon billions of cells which make up all the different parts of the body: like heart cells, liver cells, muscle cells and so on. Inside the nucleus of each cell is the genetic material that determines pretty much everything about us from the moment we are conceived to the day we die.
Before we journey back in time to retrace the evolutionary steps of humanity, let us take a quick look at those tiny things in our cells that shape us, our genes and the genome. I think of them as the fingerprints of God. This is where all the codes for our existence are kept and this is where God with a capital ‘G’ played the omnipotent role when life in the universe was created. I use this expression poetically and more for effect, so don’t take it too literally, but rather inject your own theory of how the universe was created. One of the pivotal questions I have been grappling with for 30 years is ‘why do we age and why do we die?’. A question like that may sound silly to most of us, as we have all been conditioned to accept death as the inevitable. We always hear that the only thing we can be sure of in life is that one day in the future we will die. What happens after death is the question that man has been debating for eternity from a multitude of angles and which we will attempt to answer by the end of this book. I have however purposely steered clear of an extended spiritual debate, rather focusing on the physical aspects of our being and how those have evolved to shape our present state. Some will argue that it is impossible to separate the spiritual from the physical but I hope to demonstrate that it is the physical boundaries, predetermined by our DNA at the point of conception, which ultimately dictate the pace or capacity of our spiritual evolution. But even in this relatively primitive and disease-prone state, our bodies are miracles of creation.
For those with biology or anatomy as a major, please humour me as I bring the rest of the readers into the loop. To put things into perspective on this cellular level, let us first take a quick look at the cell and its contents as this will introduce a number of terms that will help you understand some further explanations.
The CELL and its content:
The cell surface is covered with a plasma membrane and the contents consist of the cytoplasm, which contains the various organelles including the nucleus.
The plasma membrane controls flow of materials in and out of the cell, either passively, which is called diffusion, or actively by active transport. The surface is covered with vesicles or vacuoles, which are flask-like invaginations of the membrane. It is thought that these provide a crucial means for large molecules to be taken into and out of the cell.
The nucleus controls the cell and also contains the DNA (chromosomes or genome), which in turn determines all of our characteristics. Elements of these characteristics will be passed onto the next generation of offspring because of the action of the DNA. This is called hereditary transfer of DNA and it is why children take after their parents. One half of the child’s DNA comes from its mother; the other half from its father.
The cytoplasm is the whole area between the cell wall and the nucleus, where the metabolism and all the chemical reactions occur. The rate is controlled by enzymes. But the secretion of enzymes is in turn controlled by DNA.
The cytoplasm contains a number of organelles:
• The Endoplasmic Reticulum (ER) is an organised matrix of interconnected flattened parallel cavities. It is the intracellular transport system.
• Ribosomes are attached to the sides of the ER in some places, in which case it is called the rough endoplasmic reticulum. Proteins are made here. Some of these proteins include enzymes and digestive hormones, which are used by the cell, while some are secreted. The ER isolates and transports the proteins, which have been made by the ribosomes.
• The Golgi body is made up of smooth ER with no ribosomes. It is thought to be involved in the making and transporting of lipids and steroids. There are a number of vesicles nearby containing secretory granules. It is thought that the Golgi apparatus is an assembly point through which raw materials for secretion are funnelled before leaving the cell.
• The mitochondria is where respiration in the cell happens. The mitochondria also generate all the energy for the cell. There is an average of 1,000 of these per cell but there are many more in the motile tail of the sperm cell.
• Lysosomes contain enzymes for splitting complex chemical compounds into simpler sub units. They also destroy worn out organelles or even the whole cell if needed.
• Chromatin is the genetic material within the nucleus.
But cells don’t just float around on their own throughout the body. Large numbers of them are massed together to form organs and tissue. The latest estimation is that there are around 50 - 100 billion cells in an average human body, but this number changes all the time, every hour of the day. It gets more complex, as bigger people have more cells than smaller people and in the end no-one has a definite answer for the number of cells in the human body. To demonstrate the complexity of this estimate just imagine that your turnover of blood cells alone is about eight million per second. When quantities like these are in question, it is really hard to pin down an accurate number.
The cells that make up the many different parts of our anatomy all originate from stem cells, which are formed shortly after fertilisation and make up the early embryo. They divide and divide and slowly transform into all the organs and cells that make up our entire anatomy. It's like a factory that keeps on producing a large variety of end products. Every single part of your body started out as a stem cell. Several months later, the baby is born and unless it has a severe genetic defect it is perfectly complete and ready to grow into an adult human. Its body appears to be complete and ready for life but its genome is far from complete. Just like its parents, the child bears a genome that will control all of its life functions, but this genome is as incomplete as that of its parents who collectively contributed to their offspring.
THE HUMAN CELL
I remember the day very vividly. It was 1975 and I was sitting in the biology class at my high school in Randfontein, South Africa. Biology was one of those subjects that seemed to always come naturally to me, one of the lucky ones. The secret was to pay attention in class. It dramatically reduced the amount of work I would have to do on my own at home. The other trick was to ask as many questions as you could, to anticipate what might come up in the exam. The teacher took forever to draw the animal cell on the board and then stepped back to admire her masterpiece. “Right…who knows what this is?” she asked with a determined pride in her voice. She proceeded to explain all the different parts of the cell, then moved on to the very curious fact that the cells divide every few hours in some kinds of tissue and every few days in others. The new cells are born and almost immediately proceed to prepare for mitosis (cell division). This was almost too good to be true, I thought to myself. This was a perfect formula for eternal life. When you add the Krebs Cycle to the equation, the process through which energy is derived from food in the cells to keep the body nourished, it seemed pretty clear to me that the cells are the perfect structures to keep the body at peak maturity and the achievement of eternal life should be a mere formality. I raised my hand and asked the question that most probably changed the way I think about life and death today: “So why do we die, if new cells are born all the time and nourished by the food we eat?” I asked.
“We die because that is what happens,” she said. She went on to explain that this process of mitosis seems to carry on for some time, for a number of cycles or years and then suddenly the process starts to slow down. Fewer cells are born, the cells grow older and fragile with weakened cell walls, prone to pathogenic attack, until they stop dividing completely. This process spreads throughout all the parts of the body until we eventually die.
Somehow this explanation was not good enough for me and I felt that
the teacher was missing out on a very important part of the equation. There had to be some sort of control mechanism, which should be and could be manipulated to overcome this slowing down process in cell division that ultimately leads to death. But in 1975 I knew absolutely nothing about genetics and the teacher was not all that well informed either. Ever since that day I have always believed that there must be a simple procedure possible to reverse this ageing process. When genetics became the cool new science by the late '80s, it all started to make a lot of sense. Strangely enough, until the year 2004, scientists had still been at odds about the causes of ageing. Some have still not reached the seemingly obvious conclusion that just like all other anatomical and physiological functions, ageing must also be controlled by the genome. It is not only the cell as a whole that keeps multiplying, but all the parts of a cell are constantly being built up and broken down throughout its lifespan. The cell is constantly active and every bit is often renewed. When certain parts or organelles are not needed, such as extra mitochondria, they are simply disassembled and broken down to a molecular level. The truth is that once cells are born, they are truly perfect organisms that should continue to live by constantly dividing themselves for as long as they are fed. This is a great question for philosophers, since the original cell is now two cells and exists twice. Like a magician at a kiddies' party with those long thin balloons, a twist here and a twist there and soon the balloon has become two balloons. A few more effortless manipulations and the cells have become a little doggie or a rabbit or even a beating heart. That is the magic of the cells in our bodies.
THE HUMAN CELL SHOWING THE DNA IN THE NUCLEUS
The last decade has seen some new theories on cell death and ageing but to date no-one is sure why cells get fragile and ‘cranky’ as they get older. One of the popular theories in the attempt to understand ageing is a substance called ‘telomeres’. These protect the DNA from damage during copying. It is thought that the telomeres on the ends of the genes get worn away or damaged and when this happens it seems that the DNA can get damaged too. This can lead to mutations and changes that lead to ageing and cell death. This is however still one hypothesis with many others doing the rounds and no-one can speak with absolute authority. So I will use this hole in the fabric of science to postulate my own hypothesis in later chapters. The damaged DNA then starts to send the wrong messages or codes to the cell and its components, which leads to the secretion of the wrong enzymes or chemicals, which leads to the cell not performing at its peak and then it slowly shuts down and dies.
This is an important link to my argument in later chapters. All because of messed up programming and incorrect triggering of genetic responses, it is possible that the cells in our bodies die and we end up dying as a logical consequence. So if messed up cellular genetic information leads to diseases such as tumours and cancers and many other serious life threatening conditions, could we assume that the correct genetic information will do the opposite? Keep the cells alive forever? This is where genetic engineers are focusing much of their attention. We have made many breakthroughs in identifying various genes that control a vast number of physiological activities and our success rate in gene therapy and gene replacement is growing constantly. In a nutshell, by identifying damaged genes we can take steps to replace them with healthy genes.
But what if we cannot do this in certain situations. What alternatives do we have? Stem cells! The success rate we have witnessed by introducing stem cells into damaged tissue has taken everyone by surprise. While everyone was focused so fiercely on genetics, stem cell research has exploded with astonishing results. By injecting stem cells into damaged tissue, doctors have reconstituted hearts, livers and even eyes. The recovery of the organs is almost like performing a miracle, with the damaged tissue being regenerated within days or weeks. A man who had only 10% active heart muscle left had recovered to 90% within two weeks after receiving a stem cell injection into the damaged part of the heart. This is why the debate over human cloning has become so heated. Scientists have now realised that the stem cells in human embryos can be used to cure all kinds of incurable diseases, produce new organs and rejuvenate almost any part of our body. Embryonic stem cells first appear about a week after fertilisation. They are the ‘parents’ of all other cells in our body.
In theory, stem cells could be harvested from an early embryo, which was a cloned version of you, after which the embryo would be discarded. Such deliberate wastage of embryos is one reason why therapeutic cloning is so highly controversial. But the technique offers such important life-saving treatments that its use is considered justified by many people. Research into therapeutic cloning is allowed in the UK but it is illegal to place any cloned human embryo into a womb. This was intended to prevent anyone from trying to create a living clone.
But stem cells can also be found in adult bodies, where they provide ongoing maintenance and repair. Adult stem cells appear to be partially differentiated, which means they have already started moving towards becoming a specific cell type. They do however show great flexibility.
Another possible source for stem cells is in the blood collected from a baby’s umbilical cord just after birth. Some parents are choosing to freeze and store this blood so their baby will be able to call on a supply of its very own stem cells if it ever needs it later in life. I trust that scientists all over the world are already busy trying to recreate stem cells in a tube but the miracle of these cells lies embedded in the deep secrets of their genome. Not until we start to unravel some of the ‘junk’ parts of the genome and the secret encoding they possess will we start to fathom the true mechanism of stem cells. So, now that we have uncovered a possible miracle of life, let’s get back to the shortcomings of the incomplete genetic structure lurking in our cells.
The Human Genome Project was launched in 1990 and its goal was to decipher and map the entire DNA of a representative human, who was selected from a group of anonymous donors. The cost? A phenomenal US $3 billion! It has been called the biological equivalent of putting a man on the moon. The results have taken humanity completely by surprise every step of the way as the group of scientists continually made new discoveries during the course of this process. The original estimate was that the project would take about 20 years but thanks to the rapid development of computer technology it only took them 10 years. In June 2000, it was announced that the entire human genome had been sequenced. The sequence is a print-out of the structured order of four chemicals found along the length of the DNA molecule. These chemicals are referred to as letters A, T, C and G and there are an astonishing three billion variations of them along our 23 chromosomes, forming a unique sequence that holds the encoded programme for the growth of a specific person. The hidden message in this code controls everything about us; it points to our ancestry and predetermines our future. These are mainly the instructions for building proteins and millions of other secret activities that have not yet been discovered.
The big surprise to the scientists was that active genes make up only tiny fractions of the entire genome. Incredibly, they only make up 3% of the total DNA in our chromosomes. The genes are either alone or clustered together in larger groups, but in between each gene sequence, there are long stretches of DNA which do not appear to contain any type of code for anything. These stretches have now been referred to by scientists as ‘Junk’ DNA, mainly because they have not figured out what secret message it conceals. This has sparked an interesting new debate that will last until the true relevance of these dormant DNA sections is explained. Fortunately the scientists had learnt from the arrogance of their predecessors, and in their wisdom they decided to map the entire Human Genome, including the ‘Junk’ just in case it might have as yet undiscovered significance. It only took a few years to learn that those ‘Junk’ genes indeed played an important role in the structure of the genome. It is now clear that the positioning of these sections of dormant DNA are an integral part of the entire structure. More specific information will em
erge as time goes by.
It makes no sense at all that the single most important molecular structure in our body, which is also the master control mechanism, would be created incomplete or with defects. I suggest that at the point of creation, the genome was originally created to be complete and fully functional. But because it is neither complete nor fully functional, we start to theorise about its true potential and our own full potential when dictated to by the perfect genome. Every week scientists are discovering new genes with specific control mechanisms over certain parts of our body. Genes that control the colour of your eyes, your hair, your height, the secretion of enzymes, your skin, your sex and even a gene that supposedly dictates whether you will be ‘straight’ or ‘gay’. For every characteristic or function, there is a specific group of genes that controls that specific part of our body. Before we are even born, while we are growing in the womb, the genome starts to dictate how the master cells should divide and how they should shape our unique being.