What are the similarities and differences between the types and where is the boundary?

15.   THE BOUNDARIES OF TYPES
15.1  There are different genetic systems
15.2  Similarity is not proof of a common ancestry
15.3  Why does everything resemble each other?
15.4  What are the boundaries between the types?
15.5  The confusion in determining the boundaries
        between the types
       1. We can expect that it will sometimes be impossible
           to determine a boundary
       2. It depends on the complexity of the type
       3. Degeneration alienates species that are the same type
       4. Perhaps there is a genetic mechanism that
           manipulates alienation
       5. Perhaps there is a form of original variation
           in essential genes
15.6 Conclusions/summary

In the previous chapter we examined the concept of typological differentiation, and that naturally raises the question, How do you find out whether two species are the same type? Are all amphibians descended from one primeval frog, and are all mammals descended from one ur-mammal, or is it only the felines which are descended from one ur-cat, or were there two ur-cats, one big version and one little version, or were there more or different primeval felines? How do we determine types? It looks like dogs and cats will end up in different types, but how can you ascertain that the ur-wolf and the ur-cat did not share a common ur-mother as well, which was so rich in genes that not only all wolves and dogs, but also all the felines, are descended from her?

In addition to that, the fact that everything resembles each other so much has always been seen as a powerful argument for a common ancestry.
Because why does all life use exactly the same genetic code?^[1] Why are the skeletons of mammals apparently all made of the same components?^[2] Why does cytochrome C look so much the same in all living creatures?^[3] Why do mitochondria resemble bacteria so much?^[4] Why does all life have chromosomes? Why do all animals (with only a few exceptions) reproduce sexually? In short, the basis of life is the same for all life and much of what follows is the same or derived from each other, and therefore originated from each other, many say.

In order to adequately answer the question “How do we differentiate between different types?”, something first needs to be said about how genetically different life is. I will then discuss why there are so many similarities. After that, I will make a proposal for how they can be distinguished from each other.

15.1 There are different genetic systems
Why is the gender of birds and of moths determined in the sex chromosomes precisely opposite to all other organism that reproduce sexually, when birds are supposed to be descended from reptiles (or dinosaurs, as some say) and another method for determining their gender therefore had already been fixed in their genes?                                   

In humans, the sperm cell, because it contains either an X- or a Y-chromosome, determines whether the offspring will be male or female. In birds, butterflies, and some fish, the egg cell determines the gender because it contains either a Z- or a W-chromosome.
How could this immense genetic about-face have taken place? And not once, which is already sufficiently impossible, but several times! Try to create a absolute theoretical model for such a genetic about-face. It just doesn’t work.

We will complicate matters further.
In fruit flies, gender is determined by the number of X-chromosomes. 2X results in a female, 1X in a male. However, the male does need the Y in order to be fertile (Genetic analysis, pp. 69 en 70).
In mammals, it is precisely the presence or absence of the Y-chromosome that determines the gender. This was discovered by observing the gender of individuals with an abnormal number of chromosomes. In fruit flies, XXY results in female external characteristics; in humans XXY results in male external characteristics (see Figure 1). This has nothing to do with something being coincidentally genetically ‘switched around’.

Figure 1, gender determination in normal, triple, and single sex chromosomes

This is because, in fruit flies, the concentration of a protein bHLH determines whether the gender-determining gene Sxl is on or off. An extra X-chromosome, which has the gene for bHLH on it, makes the concentration higher, which causes Sxl to be produced and the larva becomes a female. If the concentration of bHLH is low, no Sxl is produced and the larva becomes a male.
The bHLH protein disappears a certain point in time during the embryonic development. However, once Sxl protein is produced, the protein itself assumes the function of bHLH and ensures that Sxl is always produced. (In electronics, this is called a flip-flop.) This is because Sxl fastens on to the mRNA (the messenger RNA, or ‘mold’) of the Sxl gene and cuts a piece out. That piece, called an exon, begins with the stop-signal UGA. If this stop-signal remains, the protein is not produced.  If it is removed, new Sxl protein is produced, which then also ensures that the right pieces get cut out again!
In addition to the fact that Sxl thus ensures its own future, it also removes those pieces from the copies of the other gender-determining genes which are not necessary for the gender in question. It is known as an RNA-binding splicing factor.

In mice and in humans, it has been determined that gender, including all external characteristics which accompany it, is determined by the presence or absence of one gene on the Y-chromosome. This is the gene SRY. If it is present, the individual will be a male, if it is absent, the individual will be a female. If this gene ends up on the X-chromosome by a mistake in recombination, the individual will receive all the male gender characteristics anyway.
SRY is a so-called transcription factor. It attaches itself to the DNA and thus determines which sex genes are or are not transcribed (that is, whether a mold of it is allowed to be made).

What is more than apparent from this is that the way in which gender is determined is totally different. In both cases, there is one gene that is the definitive switch. But:

• The way in which it is turned on or off is essentially different.
• The ways in which they then work are also totally different from each other.
• The proteins in question differ structurally.
• All the genes that are then necessary for determining gender therefore also differ from each other in the same way.

Each sex gene in fruit flies, for instance, has to contain the exact code that the Sxl protein can attach itself to, where the Sxl knows what to cut out, and what is more, can do that so that it results in a female sex protein in one case and a male one in another case.
The sex genes in mice and humans, in contrast, have to have the exact code in the DNA to which SRY protein can attach itself. This code has to be before the code of the mold, and does not end up in the mold itself. See Table 1 for a summary and an overview of the differences.

Table 1,overview of the differences in gender-determining genes in mice and fruit flies

In short, what we have here are two genetic systems that cannot be descended from each other, and cannot be traced back to some predecessor. Neither of these two systems could have been changed into the other by mutations, nor could they have descended from a common ancestor, because the differences are far too structural and far-reaching. It is known that sex reversal (‘men’ with XY-chromosomes who still have the appearance of the female sex) can, among other things, be caused by point mutations in the SRY gene. Mutations in the Sxl or SRY gene would immediately mean that only infertile males (in fruit flies) or infertile female individuals (in mice and humans) would result. Because they cannot reproduce, their mutations do not spread. The Sxl and SRY genes, and all the other sex genes connected to them, will not permit an origin in which they originate, already mutating, from a common ancestor.

There are even more gender-determining genetic systems
For those not yet convinced:

• In crickets and grasshoppers, only one sex chromosome is present. X results in a male, XX in a female (this is not the same as in fruit flies, since fruit flies absolutely have to have the Y-chromosome to be fertile).
• Bees and ants do not have any sex chromosomes. Males develop from unfertilized eggs and therefore have single or haploid chromosomes, whereas females develop from fertilized eggs with double or diploid chromosomes. The males therefore have no father!
• In crocodiles, the temperature at which the eggs develop determines what the gender will be! At 30° they all become females, at 33° they all become males!
• Earthworms and garden slugs are hermaphrodites. They all have the same set of chromosomes and can all produce both sperm and eggs.

Both in fruit flies and people, gender is determined by the XY system, but we have seen that there are already insurmountably great differences there. How much greater will the differences be in the other gender-determining systems?

Figure 2: Different ways of gender defenition. Biology campbell, pp.270

• In plants, anything can occur. Single sex according to the XY system, but also according to the ZW system; a single, hermaphroditic flower; different flowers which are hermaphroditic; some can fertilize themselves, some cannot, even though they are hermaphroditic.[5] (Genetic analysis, pp. 94 en Biology, concepts and connections, pp. 166)

Where are the hard-core evolutionists, who continually say that everything is the same, and originated from each other? Why don’t you read in their books about the origins of this sort of thing? Because it is still too complicated? Because they will eventually figure out how it works? No, because it is not possible. It doesn’t fit. It overthrows their world view, the basis of their belief, the basis of their life. This is about structural, essential, fundamentally different genetic systems that cannot be traced to each other. Even though this concerns something comparable, namely gender determination, they are different genes with the same function. Further on during the development of the sex in the embryo, tens or hundreds of genes are involved. They are different genetic systems. How is natural selection supposed to do that job? Why would natural selection want to do that job? Once the groundwork is laid for gender determination, why would natural selection want to deviate from that? Why would natural selection want to completely work out the most fundamental basis of reproduction five or six times and then introduce those different possibilities here and there during evolution? If you get it right, why change it, you might say!

The evolution theory has the problem that they have to explain every deviation from the existing pattern! Has to be able to be traced back to a common ancestry. It is fairly simply to make a general sequence: fish, amphibians, reptiles, birds and mammals. That is the picture. If you look at all the correspondences, it even becomes an acceptable picture. If you look at all the differences, it becomes a difficult picture. If you look at all the deviations and exceptions, it becomes an impossible picture! If you look at the genetic basis for the differences, it becomes a ridiculous picture!!!

Bacteria and plant and animal cells have different genetic systems
And what I have done here so far is only one thing, gender determination. But there is much more going on. A few years ago, geneticists came to the somewhat shocking conclusion that the genetic principles that apply to bacteria are not the same as in plant and animal cells (eukaryotes). People discovered, among other things, that the ‘molds’ that are made from DNA (the RNA) in eukaryotes are made up of parts which were first cut up and then stuck together (such as the sex gene Sxl in fruit flies). So the genes do not code directly for proteins, as in bacteria, but are ‘spliced’.

The discovery of spliced genes (gene splicing) signaled one of the greatest disillusionments of molecular biology.
Christian de Duve, De levende cel [The Living Cell], pp. 310.

Another point is that bacterial variation originates by transposons, insertions, deletions, separate ring-shaped DNA and the like. In eukaryotes, variation comes about through their double chromosomes and recombination, or rearranging of the double chromosomes. That doesn’t alter the possibility of these mechanisms appearing in plants and animals, as we have seen (transposons in corn and fruit flies), because the basis of DNA is, after all, the same. But in bacteria they are involved in bringing about variation and adaptation, whereas in plants and animals, they make a mess. They are different genetic systems.

And yet, textbooks talk about this as if it were all the same. It is terribly difficult if not impossible sometimes to figure out in the tomes that cover this material which genetic mechanisms occur in which species. It took me many hours and a whole lot of comparing-with-other-writers to figure things out. In one paragraph, the way something works in a bacteria is discussed, in order to say in the same paragraph that this is a mechanism which could propel evolution (this is usually expressed cautiously). That is why I am promoting this idea to an element of the degeneration theory:

There are genetic systems that differ fundamentally from each other, which are species- or type-specific. The same functions will often be realized by different genetic or biochemical systems, or, to put it more simply, by different genes.

In one type it works one way, in another type it works another way. In one it works, in the other it doesn’t. There are also many different genetic systems within one type; the immune system is one example. It is too extensive to be covered here, but for those who know, it will be clear. The way in which genes are treated there is unique. That can never be used without justification to prove something that has nothing to do with it. True, the immune system is not used as an evolutionary principle, because it is clear enough that that has nothing to do with it (since these genetic changes do not end up in the sex cells), but what is important is the idea that the different systems should be distinguished from each other, and that something that works in one system (bacteria) cannot be used irresponsibly as a principle in the other (for example eukaryotes).

Although I realize that many readers will be unable to follow me completely in this, I cannot resist clarifying this with a story, since the confusion on this subject is so great (in the books on it) that I feel it is necessary to write a bit more about it. If the shoe fits, so to speak.

Why the Russian flag was red

Because evolutionists assume that everything has the same origin, they always look for the correspondences. As soon as a correspondence is found, it is used as an argument for identical ancestry. People are not oriented to the differences. People have a tendency to lump everything together. For some reason or another, people do not realize that, just as there is a variety of living creature, there is a variety of genetic systems.
The method of argumentation used, in which things that have little or no connection with each other are nevertheless put together, resembles the following story, which was told when I was young:

Do you know why the Russian flag is red?
Because fire engines are red!

This is probably not immediately understandable, but scientists have researched it and discovered that a fire engine is red, and that the Russian flag is red, which clearly indicates a common connection: they look like each other! Scientists have also discovered that a fire engine extinguishes fires.

And paper is turned into ash by fire, they discovered.
And ash weighs about a kilogram.
And a kilogram is about two pounds.
And a pound is an English coin.
And England is situated in the sea.
And fish swim in the sea.
And fish have fins.
And the Finns fought against the Russians.
And that’s why the Russian flag is red.

No one accepts this line of reasoning if it concerns the redness of the Russian flag, but they do accept it in evolutionist genetics and/or biochemistry. Why? Because that is thousands of times more complex and the transition from one argument to the next cannot be refuted easily, and because, on this issue, people assume that the flag is red, because fire engines are red (in other words: all living things resemble each other, because they have the same common origin). Every explanation that confirms that is accepted, even if it is not logical. If someone seriously tries to refute this kind of reasoning, it could result in the following discussion between, say, Creationy and Evolutiony:

But as it now turns out, there are evolutionist writers who do address the problem of English and England, and people are fortunately making an amazing discovery, which all the newspapers then write about. It was much more complicated that people thought:

A pound is worth five pennies.
And on a penny you can see the queen of England.
And England is situated in the sea.

That just goes to show that intense scientific research will always find a solution. This logic is so watertight, no one could squeeze even a drop of water between these statements!
And yet there are still those scientific writers every now and then (like Denton and Behe) who attempt to put this logic to the test, because they have the uneasy feeling that it isn’t quite right after all.

The confusion of chromosome doubling as a mechanism for evolution
I will give one more example of confusion between genetic systems. Doubling of the number of chromosomes can occur in plants. In a certain species of cactus, this leads to huge blossoms, larger than the cactus itself. Plants have relatively simple structures and can apparently survive this kind of messing around with their genetic material, and can even benefit from it. In humans, the doubling of one single chromosome can already lead to big problems, such as Down’s syndrome, which results in mental retardation. Doubling the number of chromosomes in one species can therefore never be used as an argument to explain macro-evolution in general.

15.2 Similarity is not proof of a common ancestry
Histons are small spool-proteins that the DNA winds itself around when it is folding itself up into a chromosome. They are, as it were, the bobbins or screws that hold the DNA together. They occur in lengths of more than 100 amino acids.
I quote Prof. Dr. J.D. Fast in Matter and life, page 166:

One item of interest is a thorough research project carried out by Bonner and his colleagues in 1969. They examined a histon from a cow and from a garden pea. However far apart these organisms may be (no one could mistake a cow for a pea), their histons appear to be almost identical, differing by only three links. The cow and the pea apparently have a common ancestor, which lived on Earth before the organisms diversified into animals and plants that followed their own evolutionary paths.

The reasoning goes as follows: the histons of a cow and a pea are very similar, THEREFORE, they had a common ancestor.In A. van den Beukel’s book With different eyes, I came across a fantastic reaction to the logic of that kind of reasoning:

We will let Darwin himself speak to give an example and to tell us how he views this:
‘Wat kan merkwaardiger zijn dan dat de hand van de mens, gevormd om te grijpen, die van een mol om te graven, de poot van een paard, de zwemvoet van een dolfijn en de vleugel van een vleermuis allemaal volgens hetzelfde patroon geconstrueerd zijn? We kunnen dit aanpassing aan het type noemen, zonder daarmee veel dichter bij een verklaring van het verschijnsel te komen, maar suggereert het niet op machtige wijze een werkelijke verwantschap, de erfenis van een gemeenschappelijke voorouder?’
I think this is a specimen of very remarkable logic. Compare it with this: what could be more remarkable than the wheel of a pushcart, a bicycle, a train, the landing gear of an plane, and the cogwheels of a watch, which are all constructed along the same basic lines? We can call this an adaptation of the concept ‘wheel’ to the special needs of the implement, without getting any closer to explaining the phenomenon. But doesn’t this suggest very powerfully that pushcart, bicycle, train, plane and watch all had a common ancestor? Honestly speaking, no, not for me, and definitely not powerfully. If all those wheels suggest anything to me, it is that the concept of a wheel has been purposefully applied, by intelligent designers, to the function it needed to serve.
A. van den Beukel, With different eyes, pp. 91

The argument ‘they are very similar THEREFORE they had a common ancestor’ no longer serves.

An evolutionist walks through Eindhoven and looks at all the buildings of the city. He sees that bricks are used all over the place, for sheds, but also for rowhouses, country houses, apartment buildings, churches, and libraries, and even for simple walls. And then he sees that all the buildings have central heating and that they are also connecting to the same sewer system. And he establishes that they all have windows made of glass and that there are also doors everywhere. The electricity all comes from the same power plant, and he comes to the simple and convincing conclusion: you see, this is the clearest possible proof for a common ancestry!Analogous to the example that Mr. Van den Beukel gave (I think it is a great example), Fast’s quote can be altered as follows:

One item of interest is a thorough research project carried out by E. Volutio Nist and his colleagues in 1997. They examined the screws of a CD player and a cabinet. However far apart these objects may be (no one will ever mistake a CD player for a cabinet), their screws appeared to be identical, differing on only three points. The CD player and the cabinet apparently came from the same common production line, somewhere in a factory, before they diversified into CD players and cabinets which then followed their own process of development.

Of course we are not talking about living creatures that reproduce themselves in the case of CD players and cabinets, but a histon in and of itself is also not alive. Moreover, that detracts nothing from the argument. This is about the reasoning, the logic, the argumentation: the idea that similarity can prove a common origin. That reasoning, they-are-similar-THEREFORE-they-have-a-common-origin, does not stand up, not for living creatures and not for bricks or CD players.

If it were true that similarity indicated a common ancestry, then you could also claim that garden slugs and earthworms originated from a common ancestor and are more closely related that the garden slugs are to other slugs, because their sex-determining genetic systems are the same (or show strong similarities; see above).

Similarity does not indicate corresponding ancestry, but corresponding use! Not common ancestors, just a common basis (namely atoms, etc.). Although the earlier mentioned cytochrome c can differ in up to 50% of the amino acids between non-related species, the basic structures and functional parts are the same for all species. That isn’t very surprising, since all these species have to transport electrons. Apparently, electrons can only be picked up by one specific method, whereas the security code that causes Bouncer-protein to allow cytochrome c to pass through the membrane can differ per species (because Bouncer-protein differs just as much). The similarity can thus be simply explained by the fact that the same or a comparable function is filled.

15.3     Why does everything resemble each other?
Now that we have seen (just a little bit!) how different the genetic basis for life forms can be and that similarity does not by definition mean a common ancestry, it is an interesting time to ask ourselves why all those correspondences are there.

There is no other way
Let me try to see things from the Creator^®’s point of view, to take a look at why he allowed everything to look so much like each other (because there are similarities). That is somewhat dangerous, since I of course do not know that, but it is fairly obvious and will show in any case that there actually isn’t any other possibility than that everything looks like each other.

Firstly, all life has to find a niche on the same Earth. The atmosphere is the same for plants, animals and bacteria. Plants absorb carbon dioxide and produce oxygen, and animals absorb oxygen and produce carbon. In this way, plants and animals are dependent on each other and live in the same environment. This one single fact shows that the Creator, having made such a choice, placed incredible limitations on everything he did afterwards. That one choice seals the fate of all plants and animals. Each and every plant must in principle be able to convert carbon dioxide in some way or another. Each and every animal must in principle be able to absorb oxygen. That is why plants got chlorophyll and animals got gills or lungs.

However, a complex system such as a lung has its consequences. Hemoglobin is there, and therefore so are red blood cells, so is blood, so are blood vessels, so a heart is needed to pump, transporting the oxygen throughout the body. If an animal gets big enough, those organs collapse like Jell-O, so support is needed. For fish, a fairly flexible network of thin bones is sufficient; in larger animals a skeleton is needed. If it is good enough for one animal, it is good enough for another. The concept of a skeleton can be applied universally, just like the concept of central heating works in a rowhouse, but also in apartment buildings, schools and offices.

Suppose that, in order to convince the evolutionists, the Creator^® had made a completely different creature, one that breathes sulfuric acid and eats nitroglycerine and is made of moving stone. How could that have existed on the same planet? Everything has to look like each other, or not all life on the same earth can have a niche, because everything affects everything else. When I die, my body will decompose with the help of worms, bacteria and molds. When I eat a plant, what use could it be to me if there are nutrients in that plants which my digestive system cannot extract, except that I would not get fat? If the proteins in humans were not made up of amino acids but of something totally different, hydroxide bases for instance (which is a nonsense word), where could we get them from if the other living creatures did not have them? Not by eating them, but what could we eat then?

The design of the cell was universally applicable. The principle of DNA and chromosomes and reproduction was intended, developed, designed to be universally applicable, so that all life would be under the same umbrella. On the one hand, the Creator^® limits himself by the choices he makes; on the other hand, those choices do not limit him to such an extent that he can never deviate from them and can sometimes do something completely different. The similarities show the universal use and the universal necessary basis; the difference show the inventiveness and creativity of the Creator^®.

15.4     What are the boundaries between the types?
In this chapter, we have seen that the genetic systems which form the basis of the species differ so greatly that it is clear that typological boundaries exist. On the other hand, there are also a great deal of similarities. How can we determine the precise boundary? What I will do is discuss a number of rules with their possibilities and limitations in order to establish the boundaries, and then I will discuss a number of points which may cloud the issue of determining boundaries.

(Some rules consist of two parts, to the extent that that is practical, one to establish whether two species do belong to the same type, and one to establish that they do not belong to the same type.)

1. If fertilization of a egg cell with a sperm cell of another species occurs, then both species belong to the same type, even if it does not result in viable offspring.

99% of the time, this rule can be used to exclude the possibility. For example, it is known that apes and humans cannot fertilize each other. In the Second World War, in the camps, experiments were done to that end. On the other hand, it appears that species which have lived on different continents for a very long time can still have offspring together. In a zoo, also during the Second World War, lions and tigers were put in the same cage. They produced live offspring. Lions and tigers therefore belong to one and the same type!^[6]

Other examples are:
Horses and donkeys produce offspring. They are called mules, but they are no longer fertile. Horses and donkeys belong to the same type.
Sheep and goats can no longer produce viable offspring, but an embryo does form. Sheep and goats belong to the same type!

The North American sycamore tree and the European sycamore represent large populations that have been allopatric for at least 30 million years, but specimens that are brought together still produce fertile hybrids.
Biology, Campbell, pp. 443

It is not strictly necessary for viable or even fertile offspring to result. Degeneration of the genome can ensure that the embryo no longer develops properly and dies, or that the offspring is infertile. The chromosomes are, as it were, no longer compatible.

If fertilization takes place, that in itself is sufficient evidence that two species belong to the same type, since it is nearly impossible for mutation to change something in the melding of egg cell and sperm cell which make fertilization with the original type no longer possible, while it is possible with a sub-species. Fertilization is an extremely complex occurrence and differs from species to species!^[7] There are recognition proteins on the surface of the egg cell and the sperm cell, which fit together precisely, so that all the chemical processes that take place during fertilization only get going if the key fits the lock. A mutation could change the key, but to simultaneously change the lock in the partner in precisely the same way, so that they do fit with each other, but not with the previous combination anymore, is nearly impossible. Perhaps a comparable form of degeneration has occurred a few time in the entire history of life. What is really impossible is that, by mutation, the key of one type would suddenly fit the lock of another type.
However, if there turns out to be a genetic mechanism^[8] (especially in lower organisms) which means that fertilization between two species of the same type no longer takes place, then of course non-fertilization in those types will of course not give a definitive answer.

Furthermore, it is of course possible that the Creator^® created two different types that could still produce offspring. But that seems to me to be fairly difficult to ascertain. Perhaps you could come to that conclusion if cross-breeding did not result in one main type. It seems to me that this would occur only as a major exception.

Due to the above-mentioned reservations about the first rule, it is necessary to add two more rules that can help in determining the boundaries.

2. If a real genealogical tree is known which can be traced back to the same original type, then those species belong to the same type.

If fertilization cannot take place, but a real genealogical tree exists, not a made-up one(!), then two species do of course belong to the same type.
I have searched diligently for concrete examples which could fall under this rule (while absolutely no fertilization can take place), but I have as yet been unable to find them. The problem is that the books do talk about gamete isolation, but do not give any concrete examples of species that definitely descend from each other.This was the most concrete example I could find:

Many aquatic animals release their gametes into the surrounding water, where the eggs are fertilized (external fertilization). Even when two closely related species release their gametes at the same time in the same place, cross-specific fertilization is uncommon.Biology, Campbell, pp. 440

How closely related is ‘closely related’? And does ‘rare’ mean impossible? Or does it mean that it is possible, but does not occur?
Nevertheless, I will assume that gamete isolation does actually occur within some types, and this rule is then important.

3. If a species has one essential gene, that another species does not have, then they definitely belong to different types.

If no fertilization can take place and it is not actually known that two species are descended from each other, then genetic research could provide a definitive answer.

An essential gene is a gene that, when it is turned off, means that the fertilized egg cell cannot develop or that the individual can no longer reproduce. If one species does have this gene and another does not, then it follows fairly unambiguously that they belong to different types.
Because the essential genes determine the essence of a type (whether it is a cat-type or a dog-type and so on), a significant part of those genes will differ between the types.
With this rule, we can therefore establish without a doubt that there are boundaries, at the point where the genetic systems for gender determination differ. If the genes for gender determination are not present, because they have been damaged, the embryo may develop, but only males or only females will result, which is not very conducive to reproduction ...

If two species share all the essential genes (and there are at most a few difference in base pairs per gene), then it seems unlikely that they are still from different types.

15.5     The confusion in determining the boundaries between the types
Now that we have discussed the rules for distinguishing between the types, I need to bring up a few limitations. That is because it has so far turned out that life (on all scientific fronts!) is more complex than the simple rules with which we at first thought to be able to summarize it.

1. We can expect that it will sometimes be impossible to determine a boundary
That has to do with the idea that the Creator^® does not have to think as systematically as we would like. He made a wolf with a great deal of variation, but he also made a duck-billed platypus with incredibly little variation. Among the plants, he has almost certainly made types which could also produce offspring with each other (in order to bring about even more variation?)! It is also possible that he made two types which resemble each other, but are still really different types, such as the large pandas and the bears. The small pandas and the large pandas, on the other hand, do look like each other but definitely belong to different types.

What I want to say is that, in some cases, it could be so difficult to determine whether two species belong to the same type or to different type that you can never ascertain completely how things were originally. That is not so much an omission in my theory or in the rules for determining boundaries, but an indication of the complicatedness of living nature, which cannot easily be confined to our limited frame of reference. More so: the more problems there are, the more exceptions there are, and the more complex matter is, the more it all indicates that there was no universal, unequivocal, all-encompassing, single origin of life!
If all life really had originated by this single, simple mechanism called natural selection, not only the formation of the first cell, but also the joining of multiple co-operating cells, and the origins of complete plants and animals, and the development from simple to complex, and even all of macro-evolution and the rest, then one real exception would already be one too many. (And we have already named quite a few of that kind of exceptions.)
The degeneration theory says: because creation happened and a Creator^® with a great love of variation was apparently at work, you can expect that you cannot include all cases in rules set up by humans! The Creator^® can introduce a certain order (such as amphibians, reptiles, mammals) and then, in direct opposition to that order, make a creature that doesn’t fit in ‘anywhere’ (like the duck-billed platypus, that lays eggs and suckles its young). That is not a problem for the degeneration theory. In the same way, he could have made two original types that could cross-breed completely (which makes it difficult for us to ascertain such a thing). And yet, I think that this kind of exception generally is not predominant, and that the order is greater than the chaos. That means that we, with our limitations, can still set up rules that can be used in practice.

2. It depends on the complexity of the type
There are many different genetic systems. These can differ greatly per type or per species. One of those differences lies in the security of the genome.

In mammals and birds, DNA repair mechanisms (which correct some mutational events) are probably more efficient, and result in fewer changes accumulating in the neutral (nonprotein-coding) portion of DNA.^[9]Biology, pp. 1045

We see repeatedly that much more variation is possible in simple organisms than in higher organisms. There are millions of variants of bacteria, hundreds of thousands of variants of insects, and it diminishes accordingly right down to humans.
The question of whether we will be capable of tracing the ur-types, whether we can bring back the main types, or even if we can distinguish between the types at all, therefore depends to a large extent on the complexity of the organism. If it is a question of bacteria, forget it. If we are talking about insects, it will often be impossible. Plants? We often cannot figure it out. Mammals? It must be possible.

3. Degeneration alienates species that are the same type
Degeneration, like mutations, alterations in chromosome structure, additions, doubling and removing pieces of DNA, pollution by transposons and retroviruses, and so on, can contribute to two species of the same type differing so greatly genetically that offspring is no longer produced and, in a few exceptional cases, fertilization can no longer take place.
Degeneration could therefore create boundaries that were not present originally.
Of course, this does not detract from the fact that there are also other forms of reproductive isolation, which can produce offspring (see previous chapter).

4. Perhaps there is a genetic mechanism that manipulates alienation
A genetic mechanism could exist, mostly in less complex organisms and perhaps especially in insects, that manipulates reproductive isolation, perhaps by making it impossible for fertilization to occur between species (even if they should want to).

5. Perhaps there is a form of original variation in essential genes
It is possible that a form of original variation exists in  essential genes within the same type. That is to say, there a several alleles of one and the same gene, which are so different that they could not have originated by mutation without having lost their functionality.
If that is discovered, the conclusion cannot be drawn, only based on the fact that they do not allow mutation, that different types are involved. Precisely not if other data indicates that different species from the same type are involved.

15.6 Conclusions/summary

• There are genetic systems that differ fundamentally from each other, which are species- or type-dependent. The same functions will often be realized by different genetic or biochemical systems, or, more simply put, by different genes.
• The mechanisms within or belonging to one system cannot be a model for the evolution of all systems.
• The fact that ‘everything resembles each other’ is not proof of a common ancestry, but of common or even universal use and is a logical result of the fact that all living creatures on the same planet have to live in the same ecosystem.
• The simplest method to find out whether species belong to the same type is to see if fertilization can take place.
• The surest method to find out whether species belong to the same type is to find out whether there are essential genes which one species have and another does not.
• The boundaries of main types are more easily determined if the level of complexity is higher, because variability and deviations (in the genome) block it. In simple organisms and many plants, it may never be possible to ascertain the boundaries.