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The Damage Inbreeding Causes Demonstrates Evolution Can’t be True


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Premise: The genetic code of organisms is breaking down over time not being developed and enhanced over time as required for molecules to man evolution. I am using inbreeding as an observable example of deterioration of the genome and am ready to expand my position in the debate to follow.

Rules: Quote your sources and be respectful.


Inbreeding: The Encyclopedia Britannica defines inbreeding as, “the mating of individuals or organisms that are closely related through common ancestry, as opposed to outbreeding, which is the mating of unrelated organisms. Inbreeding is useful in the retention of desirable characteristics or the elimination of undesirable ones, but it often results in decreased vigour, size, and fertility of the offspring because of the combined effect of harmful genes that were recessive in both parents” (

Macroevolution: The gain of additional new genetic information through mutations. If the resulting change in the organism is not determined to represent a net gain in genetic information it falls under one of the next two definitions.

Microevolution/Speciation (for purpose of this debate I will use the term speciation): The process by which animals pass on or fail to pass on genetic traits to their offspring. As John D. Morris, Ph.D. explains, “The small or microevolutionary changes occur by recombining existing genetic material within the group” ( This process never results in new genetic information but frequently results in loss of genetic information. For example, dogs with short hair genes in a cold climate are likely to freeze to death resulting in only the dogs with long hair genes remaining. Rather than gaining new genetic code for log hair this dog population has lost the genes required for short hair. Mutations good or bad do not fall under this definition.

Genetic Entropy: As defined by genetic entropy, “is the genetic degeneration of living things. Genetic entropy is the systematic breakdown of the internal biological information systems that make life alive. Genetic entropy results from genetic mutations” (

Round 1
I would like to thank RationalMadman for accepting this debate.

Introduction: The premise of molecules to man Evolution requires that mutations create a net increase in genetic information over time. Genetic entropy refers to the net deterioration of the genetic code over time. Since these positions are in direct contradiction with each other, which position does the scientific information better support. For the purpose of this debate, I am not claiming that there is no such thing as a mutation that is both (a) beneficial and (b) increases the genetic code. What I am asserting is that, even if mutations adding genetic information exist, they are not statistically frequent enough to overcome the numerous mutations resulting in informational loss.

Inbreeding: It is well known that inbreeding weakens organisms over time. The miniature poodle for example suffers from a wide range of eye related issues including glaucoma, cataracts, progressive retinal atrophy, and abnormal eyelash growth. All of these issues can ultimately lead to blindness ( As Lita Cosner puts it, “’Mutts’, or even crossbred dogs, have a much lower chance of having these diseases, because many are genetically recessive—a healthy copy of the gene will override a diseased gene” ( In order for the evolutionary process to take place Inbreeding is inevitable and likely to occur repeatedly. Once the first heterosexual organisms develop the population would be very small and inbreeding would be inevitable.

Genetic entropy: The trend of accumulating mutations (genetic entropy) is not limited to inbreeding. The select few mutations that might be considered both beneficial and gains in information as required for macroevolution are massively outnumbered by detrimental mutations. In the article, ‘From ape to man via genetic meltdown: a theory in crisis’ Dr. J. C. Stanford says, “Within any physical linkage unit, on average, thousands of deleterious mutations would accumulate before a beneficial mutation would arise” ( The net result of mutations is one step forward followed by thousands steps back. This will only result in deterioration of the genetic code over time. As Botanist Alexander Williams puts it, “Irrespective of whether creationists or evolutionists do the calculations, somewhere between a few thousand and a few million mutations are enough to drive a human lineage to extinction, and this is likely to occur over a time scale of only tens to hundreds of thousands of years. This is far short of the supposed evolutionary time scales” (

Natural selection, our savior?: Now we must consider if natural selection is capable of saving the process. In the book, “Genetic Entropy” (pg. 89) Dr. J. C. Stanford says that, “Based upon numerous independent lines of evidence, we are forced to conclude that the problem of human genomic degeneration is real. While selection is essential for slowing down degeneration, no form of selection can actually halt it…. The extinction of the human genome appears to be just as certain and deterministic as the death of organisms, the extinction of stars, and the heat death of the universe.” Science supports that mutations will ultimately result in man to molecules devolution. The very premise which evolution is built upon directly defies the scientific data.

Closing: Macroevolution and genetic entropy directly contradict each other. We see genetic entropy occurring in inbred populations. If observed in small populations then (a) why wouldn’t the inbreeding of the first life form result in ultimate extinction through genetic entropy, and (b) why would a larger population serve to do anything except slow the process of genetic entropy?

There is nothing in Pro's post about why evolution cannot happen with inbreeding. This debate's resolution is not even about if evolution is true or not, but if it can be

The concept of incestuous breeding leading to deformities and genetic decay doesn't disprove evolution in any way whatsoever. Note that it most commonly happens when the mother is extremely young (think your stereotypical redneck Alabama situation or whatever).

Inbreeding's 'decay' and 'damage' are not even that strong with cousins. Entire villages of India are built on cousin inbreeding and yes, it is linked with strange ears, some people having six fingers and such (but that could also be the radiation as they have a lot of pollution there). 

Macroevolution is about the idea that over time, beings change within species and eventually the begins on 'one side' of a species and the other extreme of that species become more and more different to a point where a mutation in even just one of the people who has sex with others there means that group of children can't produce fertile offspring with the other 'end' of the species but probably can/could with the end they came from. It could be a being so extremely tall and unlike many other races of human, dog, ant that the shorter variant, especially those who are so severely different to it, end up incapable of producing fertile offspring with it. In the same way that horses and zebras, as well as donkeys, can produce infertile offspring, this being would be something that mutated enough from one side of an evolving multi-breed formation that couldn't reproduce with the 'other side'. If you're curious about species having this happen to them, even though their defining feature is that all within them of one sex can produce fertile offspring with the other (or that they reproduce asexually) then perhaps you should pay attention to inbreeding and what that would mean for the 'offshoot'.

It is actually due to the damage that inbreeding leads to that makes it so that when there's an offshoot, if they reproduce with themselves, they do indeed decay over time and go extinct. However, if they reproduce with the breed of the species that the 'mutated one' reproduced with, they can produce more and more offspring that are varied enough from each other to begin making a breed so different from the old species that over time (especially due to the fact that only those who are very different can produce fully virile and healthy offspring), it means that the species doesn't stay similar enough to their intermediary form after a while.

We can then ask 'but why didn't the intermediary offshoot keep reproducing with both species?' the answer is they probably did, but due to inbreeding leading to unhealthy, deformed and/or infertile offspring, it severely hampered the chances of the 'intermediaries of the intermediaries' lasting for long. In other words the very idea that macroevolution is impossible due to inbreeding is the complete opposite of the truth; it is only considered probable and true due to inbreeding explaining why the 'in between' beings die off.
Round 2
Inbreeding:Each offspring receives one set of chromosomes from each parent. Any mutated mistakes passed on to the child from one parent will hopefully be overridden by correct coding from the other parent’s DNA. Since the gene pool is not as diverse in inbred populations, the chance of getting a duplicated mutation from both parents is greatly increased. If your fruit salad isn’t well mixed, you’re likely to come up with two lemons.

·         First, inbreeding provides an observable example of how organisms have a deteriorating genome over time.

·         Second, under the evolutionary model, once the first two heterosexual organisms develop they will have to inbreed with each other. Naturally it is quite reasonable to assume these initial organisms will suffer from the exact same genetic deterioration process we observe in inbred populations today.

Mutations:The mounting scientific evidence supports that all genetic code is deteriorating over time. Mutations possessing both (a) a net beneficial effect and (b) an increase in the genetic code are extremely rare at best and perhaps nonexistent.

·         Beneficial Mutations: Mutations possessing the characteristic of being beneficial are quite rare.  As the quote from Dr. J. C. Stanford in my last post points out, on average thousands of damaging mutations occur for every one beneficial mutation.

·         Mutations Representing an Increase in Information: Do any of these rare mutations that represent an increase in genetic information create a net increase in information? As Dr. J. C. Stanford says, on page 17 of his book ‘Genetic Entropy,’ “There are certainly many mutations which have been described as beneficial, but most of these beneficial mutations have not created information, but rather have destroyed it…. Information consistently decreases.” Dr. Lee Spencer said, "In all the reading I’ve done in the life-science literature, I’ve never found a mutation that added information. All point mutations that have been studied in the molecular level turn out to reduce the genetic information and not to increase it." So it is highly questionable if the sorts of mutations required in abundance for macroevolution to occur even exist at all.

Limitation 1 of Natural Selection: In order to prevent extinction, natural selection can’t occur too rapidly. In general, less than one third of each generation can be selected for elimination in order to avoid extinction. Each human passes on about 100 or more mutations to the next generation. If we take a human population of 6 million people and assume that 1/3 of them don’t have children this will still result in an estimated 400 million mutations created per generation. If we consider two thirds of these mutations to be neutral and the other third harmful, the result is 133 billion new damaging mutations passed on per generation. These calculations summarize work done by Dr. J. C. Stanford, and the calculations are actually quite conservative. The rate at which natural selection can work is quite limited. Natural selection is incapable of keeping up with the high rate of damaging mutations as observed by science.

Limitation 2 of Natural Selection:Now let’s sprinkle a couple of miracle mutations into this population. Again these are mutations that are both beneficial and create an increase in information. Mutations can’t be selected individually by natural selection; rather, each organism is an inseparable package deal. In our example above each lucky lottery winner of a miracle mutation would also get approximately 33 negative mutations piled on that. It is incredibly unlikely that even a single cherry-picked specimen would receive a net increase in beneficial information through this process.

As Botanist Alexander Williams puts it, “Irrespective of whether creationists or evolutionists do the calculations, somewhere between a few thousand and a few million mutations are enough to drive a human lineage to extinction.” (

I probably will lose this debate but at this point I have zero idea what Pro is arguing. Pro has seemingly given up debating that evolution can't happen with inbreeding's damage to genes being present.

The argument in general focuses on macroevolution and how over time a species should go extinct if it's too similar to other within it, genetically. I don't see anywhere that Pro attacks this.

In biology, evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection.
  • The theory of evolution is based on the idea that all species? are related and gradually change over time.
  • Evolution relies on there being genetic variation? in a population which affects the physical characteristics (phenotype) of an organism.
  • Some of these characteristics may give the individual an advantage over other individuals which they can then pass on to their offspring. 

Nowhere in this is inbreeding's damage to genes incompatible.
Round 3
The broader parameters of my position indirectly counter Con’s position. Inbreeding causes genetic deterioration within that population over time. This is empirical science. This raises two questions:

1)      How could evolution have occurred considering that at one or more points the first heterosexual organisms would have to inbreed?

2)      If smaller populations experience quick genetic deterioration why should we expect a larger population to do anything except slow this deterioration process?

In order for Con’s explanation to be tenable, the evidence needs to support that, only under specific circumstances, the genome of each creature deteriorates.  The evidence I provided above shows that:

1)      Empirical science clearly demonstrates that organisms in large populations also have a deteriorating genome over time.

2)      Natural selection is utterly inadequate to save the day. Even under the most generous statistical models natural selection falls desperately short. Natural selection is simply incapable of removing negative mutations from a population at a high enough rate to protect the odd beneficial mutation.

3)      In order for macroevolution to work, it is not enough for a mutation to be beneficial; these mutations must also result in a net gain in genetic information. The probability of such mutations occurring range from highly unlikely to nonexistent (evidence provided in my last argument). If all retained beneficial mutations result in no change or a decline in the quantity of genetic information, all organisms would experience a continual reduction in complexity. This is not the recipe required for molecules to man evolution.

This establishes that the problem of a deteriorating genome over time is not limited to inbred populations. This counters Con’s primary argument, since his position requires that the long term net deterioration of the genome be isolated to inbred populations.

Nothing in the biological definition Con provided identifies whether the organism becomes more complex or simpler over time. If by evolution Con means change, then yes, I do believe that the genome of organisms changes over time; however, empirical science does not support that these genetic changes will result in a net increase in genetic information over time. As stated earlier, a perpetual decline in genetic information will not result in macroevolution. Although not explicitly stated, this definition does imply that evolution is capable of adding information to the genome over time. Inbreeding and empirical science contradict this implication.

Again, there are two objections that inbreeding raises against macroevolution:

1)      Why should we expect the first heterosexual organisms supposedly produced by evolution to avoid the genetic deterioration empirical science observes in inbred populations?

2)      Since the genome deteriorates in smaller populations why would a larger populations serve to do anything but slow the rate of deterioration? This position is now supported with evidence that the phenomenon of genetic entropy affects all organisms not just the inbred populations.

Round 4
Considering that there is no further rebuttal, I rest my chase upon the weight of the evidence already presented.

I fully explained. They mate with those on the end of the genetic spectrum of the species they evolved from. Their children then have cousins etc and can mate with second-cousins in the next generation so on and so forth, only one generation has to have proper incest going on.