Heckel formulated the so-called ‘biogenetic law.’ There aren’t many laws in biology. This is one ‘like’ law. It sounds very serious. What is it actually about?
Heckel claimed that the embryo of a certain species, that is, from the fertilized egg cell to the adult organism, rapidly and condensed (compressed) recapitulates the phylogenetic history (evolutionary development). Or, in a more concise form, Heckel’s law is defined as: ‘Ontogeny is an accelerated and condensed recapitulation of phylogeny.’
So, the human embryo has a phase of protozoa, then the metazoa stage, then the gastrula as a coelomate, and at a higher stage, we have the fish stage, then the amphibian, then the reptile… and finally, you get a human. So, what happened in geological history is repeated in the individual history of the individuals of a certain species.
And, Heckel’s biogenetic law played an important role in arguing the correctness of the theory of evolution. For a while, it was quite widespread and accepted. This was certainly contributed to by the fact that it is understandable and convincing even to laypeople. Because, if an individual really goes through the stages of fish, amphibian, reptile, there is no other serious reason to think except that it is repeating its evolutionary history.
It has been shown that Heckel himself falsified facts to support his ‘law.’ What is a fact is that indeed, the closer you go to the early stages of embryonic development, the greater the similarity, and the smaller the possibility of differentiation. Especially at that time, it was even more uncertain to draw embryos, as techniques for coloring and preparing microscopic specimens were not yet developed. And it really showed that Heckel drew based on his preconceived notions.
The first criticism of Heckel’s biogenetic law is (it was made to be an argument for evolution), that it is an argument of the logical fallacy of circular reasoning. What needs to be proven is taken as proven in the starting step. Because, embryonic development, as a recapitulation of phylogeny, should prove phylogeny, which has already been derived from embryonic development.
How do I know that this is a recapitulation? I know because there was evolution. And how do I know that evolution existed? Well, I know based on embryonic development.
For example, rudiments. How do I know that something is a rudiment? Why is a certain organ a rudiment? Well, a rudiment is because there is evolution, and because this organ originated from that organ, and in the ancestor, it was functional, but in the descendant, it has atrophied.
This is logical hocus-pocus. With evolution, I prove rudiments, and with rudiments, I prove evolution.
You know, evolutionists say: “Molecular fossils.” (As biology conquers areas, “evidence is gathered” for evolution.) For example, we have molecular fossils, such as introns. And how do you know that introns are molecular fossils? Well, I know because they are present in certain types of bacteria and in humans. And since they have a common ancestor, there was evolution, these are molecular fossils. They are the same structures in both humans and certain types of bacteria.
And then you turn a few pages further and read: “Molecular evolution: Well, molecular fossils are an obvious proof that evolution existed.” Based on evolution, you construct evidence for evolution.
And based on, therefore, embryonic development, phylogeny is reconstructed, and that same phylogeny is later proven by embryonic development. That is the first part.
Second: There is no parallelism between the development of certain structures in embryonic development and their alleged appearance in phylogeny. Let us take some examples:
In phylogeny, bone appears first, and then cartilage (you first have PlacoDerm (fish that possess bone), then you have Chondrichthyes (fish that possess cartilage)). This means that in phylogeny you first have bone, and then cartilage, while in embryonic development you first have cartilage, and then bone. So, it is the opposite.
In embryonic development, you first have the heart, and then the blood vessels, whereas in phylogeny you first have blood vessels, and then evolution had to continue for a long time to form the heart. You know, when you take a chicken embryo, first you see a large heart, and from the heart, blood vessels extend. And in phylogeny, you have some primitive animals that only have some blood system, and later, in more advanced organisms, the heart is formed. Again, it’s the opposite.
In phylogeny, you first have nerves, and then the brain (in the so-called process of cephalization). And in ontogeny, you first have the brain, and then nerves. Everything is the opposite of Haeckel’s law.
Or, for example, the development of the heart: when you look phylogenetically, you first have one chamber, then one atrium and one chamber, then two atria and one chamber, and finally, you have two atria and two chambers.
If ontogeny were truly a recapitulation of the alleged phylogeny, then according to this diagram, the heart should develop in the same way in humans. And how does the heart develop in humans? In humans, heart development starts as a two-part sac, then everything merges into one whole, and then suddenly four parts develop, and it is specially connected to the mother’s circulatory system.
There is a small number of evolutionists, those of the old kind, who still believe in Haeckel’s law.
There exists the so-called ‘law of preservation of individuality.’ Just as there is a law of preservation of mass and energy in nature, so there is also in biology, genetics, a law of preservation of individuality. An individual is defined at the moment of conception, and it has a specific set of genes, for example, in humans, which has nothing to do with fish, frogs. A human being or a being of another species is from the very beginning a human being. So the question: ‘When does a human being emerge in embryonic development?’ is the wrong question. When does a human being emerge? When is he a human being? He is a human being from the very beginning. The egg cells themselves are different. But, due to certain circumstances in which we live, it is perfectly normal for our embryos to develop similarly to animal embryos. Considering this is similar to considering the question of homology. Why do we have similar limbs as other vertebrates? You cannot distinguish this just like that. You must do it based on some external criterion, and not on the basis of homology itself. The problem of similarity (homology) cannot be solved just by studying the similarities. Well, of course, we have to be similar because we breathe the same air, eat similar food… How can we not be similar to the living world with which we are created. We cannot live in a world of animals that look foreign to us.
In order to distinguish which theory is correct, you must make opposing predictions. If both give the same predictions, you cannot distinguish based on that criterion.
It would be most beautiful if it were as Malpighi said: ‘That we were all preformed since Adam.’ People asked: ‘How do descendants resemble their parents?’ How is this determined? How is this decided? And then it was easiest to solve it by saying that ‘descendants are preformed in their parents.’ They are there as small, they have all the qualities, and only quantitatively increase.
And then someone asked the question: ‘And where are they preformed: in the egg cells or in the spermatozoa?’ They cannot now be preformed in both. And then the scientists split. It’s always like that. Those who claimed that they were preformed in the spermatozoa were called ‘animalculists,’ and those who claimed that they were preformed in the egg cell were called ‘ovulists.’
Animalculists said that the egg cell only provides food, because an embryo cannot develop without food. And ovulists said that the embryo does not need food, but it needs initiation.
And then Anton Van Leeuwenhoek observed spermatozoa, and he drew them and called them ‘animalcules,’ in which a small embryo, a little human, sits. That is the theory of preformation. He is preformed, it just needs to come to expression. Just like in theology ‘predestination’ – everything is predetermined, it just needs to unfold.
And then biology progresses and it is discovered that there is also parthenogenetic reproduction. That means, from unfertilized females, offspring are produced. And, the ovulists win.
However, when they calculated, over several generations, this preformed one would have to be smaller than an atom. Because, the theory was: ‘When God created the world, He predetermined all people in the first created pair.’ And then simple recalculations showed in how many generations this one would have to be smaller than an atom.
Now we know that genes are information and that this is transferred informatically, not materially. All animals begin from one cell and there is similarity in the initial stages, but not because of recapitulation of evolution, but because of the way embryonic development is defined.