- The Laws of Science
- The Doctrine of Uniformitarianism
- The 1st Law of Thermodynamics
- The 2nd Law of Thermodynamics
- The Four Fundamental Forces
- The Big Bang
- The Age of the Universe
- The Age of the Earth
- Star and Planet Formation
- The Origin of Life
- Macro and micro evolution
- Darwins Evidence
- Punctuated Equilibrium
- Isn't Evolution "Just a Theory?"
- Is It Really That Important to Teach Evolution?
- Intelligent Design
- Conclusions from Science
- Environmental Change and Species Extinction
- The Bible
- Objections to Christianity
- Suggested Reading
Genes, Mutations and Neo-Darwinism
The Facts of Genes, Mutations and Neo-DarwinismDeoxyribonucleic acid (DNA) is found in the nucleus of almost every cell. A gene is a section of DNA that code for a particular trait. DNA is composed of a long series of what are called nucleotides. Each nucleotide is itself composed of a sugar (deoxyribose), a phosphate and one of four chemical bases- guanine, cytosine, adenine, and thymine. The four bases are usually abbreviated by their first letter: G, C, A and T. Three nucleotides in a row are known as a codon. Each codon "codes" for a particular amino acid. The bases GCT might code for a different amino acid than say GGG. The different amino acids bond together like the beads on a string. A particular string of amino acids that has a function within the cell (such as eye color) is known as a protein. Each protein has a particular three dimensional shape that determines is function. The proteins three dimensional shape is dependent upon the order of amino acids that make it up. Proteins are the workhorses of the cell. They can form the structure of the cell or they can control the chemical reactions that take place within the cell. They are even responsible for our bodies ability to defend itself from disease.
If you change the order of the amino acids then you change the function of that protein. It is the code contained within the DNA molecule that determines the order of the amino acids making up each protein. A gene mutation is a change in the order of the DNA bases, or nucleotides, which results in a different order of amino acids which then causes a change in the shape of the protein. When the shape of the protein changes its function also changes. As an example consider the following: "thedogran". If this "code" is read three letters at a time it spells out: "the dog ran". But if you were to add a letter (addition), change a letter (substitution) or subtract a letter (subtraction) from the series then it would say something very different. This is how a gene mutation can change a proteins function. Mutations can occur naturally over time as cells make copies of their DNA. Gene mutations can also be caused by mutagens such as ultraviolet radiation and chemicals.
The current thinking regarding evolution is that it is the slow build up of mutations that make physical changes to an organism. Those physical changes are then acted upon by the environment to naturally select some individuals for survival and some for death. Those organisms that survive and reproduce will pass those changes on to their offspring. It is in this way that the changes to the organism will be retained in the population. Over time as these different changes add up the organism will no longer be able to breed with the original population and a new species will have been created. This concept is known as neo-Darwinism. Neo-Darwinism is really Darwinism with gene mutations replacing pangenes as the method by which Lamarck's acquired characteristics are passed from parent to offspring. Neo-Darwinism is accepted by most scientists and is taught in most schools.
Observations on Genes, Mutations and Neo-DarwinismLet's first consider the mathematical probability that mutations could be responsible for the evolution of living organisms. We will start with single celled organisms that reproduce asexually. We will then consider multicellular organisms that reproduce sexually.
For asexual organisms, such as bacteria, the concept of mutational change seems simple enough. Bacteria are single celled organisms that reproduce by a process known as binary fission. In a bacterial cell the DNA will make a copy of itself. The bacteria cell will then divide into two new cells. Each new cell has a complete DNA code identical to its parent. Any change in the DNA of the bacteria will he passed directly to the offspring. If these bacteria survive then the mutation will become part of the population. If these bacteria do not survive then the mutation will be eliminated from the population.
But what about sexually reproducing organisms? Of all the mutations that may take place the only ones that can have any effect on the offspring are the ones that take place in the sex cells - egg and sperm. The vast majority of mutations have absolutely no effect on the species. They affect only the typical body (somatic) cells.
Let us now assume that a mutation does occur in one of the sex cells. The odds are that it has no effect at all. If it does have an effect the odds are that it will to produce an odd protein. This mutation may even kill the cell. But for the sake of argument let us assume that against all the odds this mutation successfully gets passed on to the offspring. What now?
If this organism were to die before reproducing, as almost all organisms do, the mutation would disappear from the population. If this organism did reproduce then the mutation would be passed on to the offspring. The offspring would however have only one copy of the mutation (remember genes come in pairs). When, or if, this offspring reproduced there would be only a 50/50 chance that their offspring would acquire this particular mutation. Very few mutations ever become established in the population. Those that do are often eliminated in a just a few generations.
The vast majority of mutations have no effect whatsoever. This is simply because the vast majority of DNA within a cell is not active. Most of DNA present in a cell has no known purpose. This DNA is known by the the very misleading name of "junk" DNA. But like vestigial structures, just because we do not know what it's function is does not make this DNA "junk".
But lets get to the DNA that we know does have a purpose. It turns out that almost every cell of the body has exactly the same DNA. (Mature red blood cells do not contain DNA) An eye cell has the same DNA as a toe cell, a liver cell or a brain cell. The eye cell uses only the DNA that an eye cell needs. The toe cell uses only the DNA that a toe cell needs. If a mutation were to affect the DNA in a toe cell that is used for the eye there would be no effect. This is because that particular DNA is not active. Toe cells do not need any DNA for vision as toe cells cannot see. Almost all of the DNA in a any particular cell is in an inactive state. Therefore almost all mutations will have absolutely no effect on the cell.
A simple way to think about all of this is to compare DNA to a cookbook. Every cell has a complete cookbook (DNA code) inside itself. This cookbook has recipes for peanut butter cookies, tomato soup, carrot cake and so on. If you wanted to make peanut butter cookies all you would need is the recipe (a section of the DNA) for peanut butter cookies. If the carrot cake page was ruined (mutated section of DNA) it would not make any difference for you only need the peanut butter cookie recipe, not the carrot cake recipe.
Some rare mutations may have an effect on the DNA that is being used by that particular cell. These mutations may result in the tableion of an odd-shaped protein. This odd-shaped protein may have a small effect on the cell. But it also may not affect the cell at all. A person with blue eyes may have one cell out of a million that is green in color. If you were to look that person in the eye then that one cell would be very difficult to identify.
Some very rare mutations that do have an effect may result in the death of the cell. The protein that is produced, altered or not produced may cause that particular cell to die. But every day millions of cells in the human body die. Humans loose thousands (if not millions) of cells each and everyday. I myself have never noticed the death of any one particular cell.
Some of the very, very rare mutations that do have an effect may result in the death of the organism. Cancer, cystic fibrosis, and sickle-cell anemia are just a few of the diseases caused by mutations. These mutations, with their resulting odd proteins, or uncontrolled cellular retableion (mitosis), may lead to the death of the organism.
But what about the offspring? A fundamental tenant of evolution is that mutations are passed on from generation to generation. It is this inheritance of mutational change that results in "decent with modification".
To recap: The vast majority of mutations will have no effect on the cell or the organism. The few mutations that do have an effect will do one of three things. They will: lead to the tableion of an odd protein, kill the cell or kill the organism. And, the only mutations that can have any affect on the population are the ones that take place in the sex cells.
But what about those mutations that are good for the organism? What about all those "beneficial" mutations? Well, there aren't any that are known of. The closest we can come to a beneficial mutation is the one that results in a disease known as sickle-cell anemia.
Sickle cell anemia is a disease where the red blood cells have a sickle shape rather than the bi-concave shape that they should. As a result these red blood cells cannot carry as much oxygen as they normally would. This results in a type of anemia. But this "sickle" shape also hinders the cells from being invaded by the plasmodium that causes malaria. Individuals that are heterozygous (only one section of DNA coding for the trait) for sickle cell anemia are more resistant to contracting malaria than people without the mutation.
At first glance this mutation would seem beneficial. After all millions die every year from malaria. But lets look at it more closely. If an individual was homozygous for the trait (both sections of DNA coding for the trait) they would die - of course "they" are your son or daughter - before their 3rd birthday. If your son or daughter were heterozygous (both alles code for the trait) they would be physically tired for most of their life. They would live to about 30 years of age and then die.
If this so-called "beneficial" mutation is one of the causes of evolution then the theory itself is in a lot of trouble. Sickle-cell anemia is a disease not a cure. But the problem of mutations do not end here.
If your eye or toe cell mutates it affects only you. Almost every mutation, if it has any affect at all, affects only the individual. These mutations do not get passed on to the offspring. Only two cells, just 2, get passed to the offspring. One egg cell from the mother and one sperm cell from the father unite to form the new individual. Only those mutations that take place within these two cells can be passed on to the offspring. There are over 2,000,000,000 cells in the human body. Only one cell is passed to the child. What are the mathematical chances that this one cell had one mutation that was beneficial for that child? Just about zero.
In spite of the overwhelming mathematical odds against it some may still insist that mutations are responsible for Darwin's decent with modification. Let us now look at what the scientific evidence has to say regarding the effect of mutations on the species. Fruit flies are used to study mutational effects because they have four important properties essential to scientific experiments: they are small and easy to contain, they are easy to feed, they have a very short retableive cycle and they have a relatively small number of chromosomes. These four properties make fruit flies ideal for studying the effects of gene mutations. Fruit flies were originally chosen for study by Thomas Hunt Morgan for these very reasons.
Morgan was a pioneer in mutational studies. His personal home in Woods Hole, MA has morphed into the now world famous Woods Marine Laboratory. Scientists from all over the world come to Woods Hole. Students of science aspire to get a apprentice position at Woods Hole. Morgan first studied fruit flies at Woods Hole. Morgan and his associates cataloged millions of fruit flies and mutational changes at Woods Hole. It can be said without reservation that Morgan's fruit flies laid the foundation for mutational studies and evolution.
This same line of fruit flies that Morgan worked with is still being studied at Woods Hole to this day. These fruit flies, with their 21 day retableive cycle, are the descendants of the original fruit flies studied by Morgan. And yet, if Morgan were alive today he would not be able to distinguish the fruit flies presently in the laboratory from his the one he studied over 100 years ago.
These fruit flies have been intentionally mutated many times over many years. These flies have been subjected to heat, chemicals, radiation and a whole host of other mutagens. These same fruit flies have been raised in hot, cold, light, dark and who knows what else types of environments. And yet I do not think that Morgan would not be able to see any difference between his fruit flies and the ones here today.
So what were the end effects of all these mutations? Fruit flies that are born with legs sticking out of their heads. Fruit flies that are born with no legs at all. Fruit flies that are born dead. After all these mutations what was the end result? Many poor, sickly individuals. Individuals that have no chance of reproducing. There is absolutely no scientific evidence that indicates any type of benefit for the fruit fly resulting from these repeated mutations. On the contrary, the effects of these mutations seems like something out of a horror movie.
After 100 years of fruit fly retableion with thousands of offspring, with multitudes of mutations we are left with the same fruit flies that we started with. Let us now consider the Beluga whale. This mammal produces one offspring every three years. How many millions, no it would be billions, of years would it take for Beluga whale retableion to be equal that of the fruit flies or bacteria? And yet we are lead to believe that it is by the slow accumulation of mutation that we evolved from single celled organisms. This idea has no scientific basis.
There is no doubt that mutations do occur within individual organisms. Mutations happen more frequently when there are more mutagens around. A mutagen could be U.V. radiation, nuclear decay, X-rays, gamma rays, chemicals, etc... In some cases mutations are caused by the incorrect copying of individual genes during mitosis (cell division) or meiosis (tableion of sex cells).
Mutations are said to be the driving force behind biological evolution. Most scientists believe that without mutations all living things, including the human race, would not be here. This leads to a very interesting question. Does anyone intentionally subject themselves to mutations? Do we send our children outside into the sunshine without sunscreen? Does the dental hygienist stay in the room with us when our teeth are X-rayed? Does someone ever desire to build their home next to a nuclear energy plant? Why not?
The answer is obvious to anyone who reasons logically. We all know that mutations cause disease and death. We do our best to avoid mutations at all costs. Mutations do not make us better they make us worse. Everyone know that this is the case. Everyone except for evolutionists of course. They claim that without mutations life would never have evolved.
Tell your children that they need to eat their vegetables to grow strong. Then tell them that if they eat those same vegetables they will get sick. Which is it they say? Should we eat our vegetables or not? It is the same with gene mutations. We are told that they are the cause of evolution from a single celled organism into all of the beauty we see here on earth. Trees, butterflies, lions, whales and every living thing is here by the power of some gene mutations that happened in the distant past.
Yet somehow today we see people dying agonizing deaths due to mutations. We see our friends suffer terrible genetic diseases. We witness the suffering caused by emphysema, Crohn's disease, hemophilia, Downs syndrome, cystic fibrosis, colon cancer, Alzheimer's, Turner's syndrome, and the list goes on and on and on. These diseases, and many, many more are all caused by gene mutations.
Mutations replaced Darwin's mythical pangenes as the carrier of acquired characteristics. Mutations have been proved to cause disease and death. Evolution can still be accepted as the method by which life arose but genetic mutations cannot be the cause. If evolution is true then there must be some cause other than gene mutations. Mutations do not bring life they bring death and disease. Whatever may cause evolution, if it is in fact true, the evidence is clear: it cannot be mutations.
Home » Science-and-christian-belief » Neo-darwinism