Imagine you work at a car factory where you test drive every car that comes off the production line. If there is anything wrong with the car, such as performance problems or annoying noises, you take it out to the crusher to be recycled into scrap. Suppose one car has a problem with the engine so that it is less powerful. This is easily noticeable and you send the car on to the crusher.
Now suppose a car comes off the production line with a single rust molecule hidden somewhere in the metal. This has no effect on the physical performance of the car, so it is unnoticeable and the car continues on in its life. Eventually, that rust will spread so that the entire car becomes useless.
And we have the same problem with biology.
A mutation is generally any error during the copying of DNA. So when babies are produced, mutations can creep into their genome. But how many? If we only count mutations that change a single genetic ‘letter’ (point mutations), there are an enormous 100 to 300 new mutations occurring in every person in every generation! So that means if your parents have no mutations, you have 100-300, your children will have 200-600, your grandchildren 300-900, and so on.
Essentially all of the mutations are damaging in some way. They cause ageing, diseases, and cancer, and one would be hard-pressed to find any example of a truly beneficial mutation (examples of beneficial mutations also involve the harming of DNA, therefore not truly beneficial in nature).
The startling thing is that most of the 100-300 mutations per person per generation are unselectable. That is, they are invisible to natural selection just like single rust molecules are invisible to a car inspector. Natural selection occupies a very important place in evolution. It removes animals with damaging mutations, and keeps those with good mutations, thus allowing the species to be the best it can be. But with unselectable mutations, natural selection can do nothing!
Unselectable mutations are the Trojan horse of evolution. They come in silently, being so small that they can infiltrate the entire population without being removed by natural selection. Eventually, they build up to such a point that they are fatal to the organisms and the population becomes extinct.
The more time we give evolution to ‘work wonders’, the more organisms become extinct. Time is not the hero of the plot – it is the enemy.
This mutational meltdown described above, also called genetic entropy, is at work in all multi-celled life. So this is a huge affair.
Alex Williams has shown that the extinction of life would take only a few thousand years, assuming that 100 new mutations occur per person per generation and generation times are 20 years.
The very core of modern neo-Darwinism is mutation coupled with natural selection. But the actual data show that the overwhelming number of mutations are harmful (even if only slightly harmful), and that natural selection is useless most of the time. It cannot “see” most of the mutations in order to get rid of them. Far from being a viable mechanism for evolution, mutations sound the death knell for the evolutionary theory of common descent.
[Note: This article is an overview of mutational meltdown and genetic entropy – you are referred to the scientific literature upholding what is said here for a more in-depth discussion. Articles in the Journal of Creation (also published on creation.com) are a good place to start.]Possible Responses
“Most mutations are not harmful but neutral.”
This response misunderstands the point at hand. Sure, most mutations are neutral from the perspective of the organism’s physical fitness (phenotype), but all mutations must have effect on the genetic content (genotype). In no way are mutations truly neutral – they all must have effect on the genotype, even if they only affect the efficiency of transferRNA production. And as pointed out above, most are harmful.
“Almost all of the unselectable mutations will occur in non-coding regions of the DNA (the so-called, Junk DNA), and therefore have no effect. Thus, the individual will not die and the population will not become extinct.”
Non-coding DNA does not code for proteins and scientists have previously thought it is largely useless. But mutations in the non-coding DNA won’t make them without effect since non-coding DNA helps during embryonic development and can be a part of many diseases.
The idea that non-coding DNA absorbs mutations, thereby making them neutral, is false and is merely an argument from ignorance.