The Origin of Life

30-11-2010 20:55

During the period that elapsed from the release of the work The Origin of the Species, by Charles Darwin (1859), in which he ignored the origin of life, until the current days (2006), many speculations on this theme were worked without convincing all the specialists, although many of them had received scientific approach. In the last half of last century, biology tried a great progress, to the point of deciphering the genetic code responsible for the cellular multiplication and to promote the cloning of embryos. Laboratory experiences allowed the formulation of coherent, plausible and acceptable theories on the origin of life, obviously without the character of true, as the ones that were presented, almost simultaneously, by J. B. S. Haldane (1892–1964) and Alexandr Ivanovitch Oparin (1894–1980).

We will examine, very concisely, the hypothesis of the Russian chemist Alexandr Ivanovitch Oparin (1894–1980), published around the year 1936, a version more or less accepted by scientists (biologists) about the first "living" beings´ formation. Oparin had knowledge of astronomy, geology, biology and biochemistry, using them for the supposed solution of this problem. He observed in his studies of astronomy that some planets of the solar system possess reducing atmosphere with the presence of gases such as Hydrogen, methane and ammonia.

By analogy, Oparin admitted that, when the Earth was formed and solidified itself, still hot, frequent storms happened with electric discharges (lightnings) and these would have provoked chemical reactions among the previous mentioned elements and steam, forming more or less complex molecules of amino acids. Thus, it seems very probable that in the origins of the Earth formation, the atmosphere of the planet consisted of Hydrogen, steam, water, carbon dioxide gas, sulfurous vapors, ammonia and methane. There was no Oxygen in the atmosphere, which was reducing (the contrary of oxidizing) par excellence. The steam was originated from the intense volcanic activity that, even today, is brought by the volcanic magma to the surface of the Earth to the proportion of up to ten percent. With the cooling of the Earth, the oceans, seas and primitive lakes were formed, well different from the current ones. In some moment, during the Archean period (3.5–2.5 billions of years ago) of the pre-Cambrian era, the first chemical "bricks" appeared in the form of amino acids and proteins. With the persistence of the rains, during thousands or millions of years, the amino acids and proteins were dragged and taken towards the lakes, seas and oceans. For an incalculable time, these proteins combined and re-combined themselves, multiplying qualitative and quantitatively in the lukewarm waters of the referred lakes, seas and oceans. Dissolved in water, they formed a type of chemical "soup", which could have concentrated itself in some points, who knows, near the beaches and crags, to give place to the formation of colloids. The interpenetration of the colloids took to the formation of the coacervates (10), a special type of colloid.

This hypothesis is plausible because, in the universe, in many stars, the spectral analysis reveals the presence of molecules of ammonia and organic molecules of small size, as the hydrocarbons compounds. Laboratory experiments simulated the conditions probably existent on the Earth in the beginning of the emergence of life, passing electric discharges (simulating the electric discharges of the storms) through a mixture of gases containing Hydrogen, steam, ammonia and methane, thus synthesizing organic molecules of the amino acids type (molecules that contain Carbon, Hydrogen and Nitrogen). These experiments were made by Harold Urey and Stanley Miller, around the year 1952. The following step was to create laboratory conditions for the emergence of the macromolecules that could self-duplicate, producing copies of themselves and this was obtained, although, subjected to many conflicting opinions.

With this information, it was theorized that, with the accumulation of molecules of the type of the indicated ones, subjected to very restrict spaces, it would have given place to the formation of a chemical "soup." This, who knows, by the catalytic action of clays (mud) and other metallic elements, or even certain enzymes or ferments synthesized during a long process, would have formed molecules of nucleoproteins and lipids, coupled to the colloidal structures, known as coacervates. The interaction among coacervates, nucleoproteins and lipids would have created the necessary conditions so that the cells appeared, in the first unicellular beings´ form – the prokaryotes (cells without nucleus). It is suspected that the first oldest already found fossils were carbon-dated as having about 3 billion of years, came from the prokaryotes. A very detailed description of that process can be seen in reference (9) and, mainly, in the reference (11). We extracted from a work by Professor Cynara Chemale Kessler, the following (9):

In this aspect, the colloidal structure of the organic matter would have given place to the cellular membranes. The problem of the great molecule synthesis is subdivided into two, interdependent: the first, just deals with the emergence of the molecules that are known now; and the second, refers to the way by which the transformation of the state of a simple "soup" of organic molecules into the emergence of organized cellular forms occurred.

For the first problem, the answer is apparently paradoxical. Let us imagine a small protein formed by twenty amino acids of fifty varieties. Breaking this protein and rearranging its amino acids, of all the possible forms, the result will be a number very high: the unit followed by 48 zeros. Therefore, if in the primitive seas all the combinations were possible (and no doubt, they were), why then, only some of them have produced life? The paradox is in that such combinations sprout up exactly because they produced life.

Possibly, they appeared other macromolecule types, besides RNA (ribonucleic acid) and DNA (deoxyribonucleic acid), but only these last ones got to organize in small units, auto-replicating units, using the other ones as food, in a type of "cannibalism.” With that hypothesis, it is admitted that the prokaryotes (represented by bacteria and algae, whose cells don't contain nuclei), the first living beings, were heterotrophic, like the animals and current fungi that eat other living beings to survive. Only after many years later, at about 1.5 billion of years ago, they appeared the eukaryotes (living beings whose cells contain nuclei) – autotrophic, living beings that create their own foods, like the current vegetables. This would have been possible with the emergence of the chloroplasts, which form the chlorophyll inside the cells. According to this version, the animals (monera kingdom – bacteria and certain algae deprived of chloroplasts, type cianoficeas or blue algae) would have appeared before the vegetables.

Finished the initial cannibalism that lasted millions of years, the unicellular beings evolved to a stage of complexity that allowed them the use of the photochemical reactions. With that photosynthesis mechanism (transformation of the atmospheric carbon dioxide gas by the chlorophyll into organic products that constitute the vegetables, with liberation of Oxygen), the incipient life was avoided of extermination, represented by the prokaryotes, what it would have occurred if the cannibalism among them continued. One should mention that, until the appearance of the eukaryotes, life was organized in the seas, under the waters, because the atmosphere was essentially reducing, with only 0,001% of Oxygen. Only counting from 1.8 billion years ago, the atmosphere would have reached high levels of Oxygen (today, about 21%), in function of millions of years of photosynthesis done by the primitive unicellular beings (green algae), mainly through the oceanic plankton. (10)

Thanks to the improvement of the electronic microscopy, besides other techniques and in agreement with the structural type of the cells (prokaryotes and eukaryotes), Whitaker classified the current living beings in five kingdoms: monera (prokaryotes: current bacteria and certain algae), fungi, protists (protozoa and unicellular algae), animal (multicellular), vegetables (multicellular), the last four mentioned being all eukaryotes. (12)

As we said, the above hypotheses are plausible. But organizing the Matter itself, even in a complex and favorable structure to support life, doesn't mean that life is present and, in this fact resides the difference between to exist and not to exist as a being, even that it is a single cell. It is necessary to start on it the metabolic process, or say, to “ingrain” in it the Intelligent Force, which guarantees to it the existence of the so-called "life", be it as an autotrophic or heterotrophic cellular form. Where life does come from? Or, how did life originate? Will it be that when replicating an amino acid molecule, a nucleotide or even DNA itself, also means the reproduction of life?

Let us take, for example, a real case of just one cell, which contains about 20 amino acids and that have their functions ruled by hundreds or even more than 1,000 specific enzymes. The probabilities that these molecules come to join themselves and form the proteins and the polypeptides needed to create life in the cell is in the order of many billions or even trillions of years to one, which is much beyond the total age of the universe.

This is equivalent to say that this chance is null, or that life was not created on Earth by chaotic chance. It is from Francis Crick, Nobel Prize in Biology and discoverer of DNA structure, the saying: "A wise man, endowed of the whole knowledge at his disposition today, would have the obligation to affirm that the origin of life seems, now, to be due to a miracle, so many are the conditions to make it possible.”

Taking the cell, and therefore, the multicellular beings as systems capable of taking care of themselves, in a countless of special functions, is not enough. The amino acids formation mechanism and their higher compounds, the polypeptides inside the cells, do not mean to explain the mechanism of life in the living beings. There still remains the problem of cells reproduction and a lot more of intricacies. All talk-about of the system biologists are merely mechanical and purely chemical; no life at all is involved.

As it is well known by scientists, it is not easy to elaborate the prototypes of the nucleotides. These are the basic compounds that, by their turn, lead to the formation of the fundamental molecules, bearers of life, which are represented by the emergence of the ribonucleic acid (RNA) and of the deoxyribonucleic acid (DNA). The RNA molecules are responsible for the energetic functioning of the cells and the DNA is the bearer of life code, unique for each living being. Much more difficult is to put these essential molecules to work for explaining life in the cells. After all, what does initiate life and sustain it as a living dynamic system?

Therefore, since the beginning it was necessary that those first cells would have learned how to “replicate themselves" from the linkage of their basic proteins. After that, they themselves were in conditions of manufacturing new proteins, similar to all the precedents. The real subject is to know how the things happened in that apprenticeship: how those very first cells invented the countless stratagems that led to this prodigy of the reproductive process.

How could those precious agglomerates feed themselves? How could those small marvels of the nature guarantee their perennial life? How could they guarantee their replication or reproduction? While these fundamental questions don’t get the right answers, it is necessary to insist on them, once again, that none of the operations above mentioned might have been made at random.

Another necessary consideration is that evolution of the Matter towards life contains in itself an order. Therefore, of what type of evolutionary order are we talking about? It should be emphasized that as the chance tends to destroy the order, the intelligence follows the contrary path to establish the order or organization of the “things.” Thence, we should conclude, by observing the insurmountable complexity of life that the universe itself is "intelligent.” We are speaking of an intelligence that transcends what exists in our plan or reality. Probably, from the primordial flaring forth to nowadays of what is called Creation, the Intelligence organized the Force and the Matter to create life, to put them according to the immutable laws of the universe. Once more, which is the true nature of that "order", of that perceptible intelligence in all of the dimensions of our reality?

It was Carl Jung who said that the emergence of “significant coincidences” necessarily implicates the existence of an Intelligent Force or principle, which should put together space, time and causality. We are talking about the synchronicity principle. The fundamental basis of this great principle is the universal order of comprehension linked to the causality principle. There is no random event in the beginning of the Creation. That means, we can imagine, no chance at all, but a higher degree of order, which is infinitely superior to all that we reasonably can imagine. That supreme order rules the formation and behavior of the atoms, the chemical and physical constants, the formations and movements of stars and galaxies, and so on. This immense free Force is powerfully ordered, infinitely existent, implicit, invisible, sensible and eternal. It is in each particle actuating on all the phenomena of the universe.

From what was exposed in the preceding paragraphs it was verified that we are not a simple product of this small planet, or then, in accordance with Theodosius Dobzhansky's saying: (2, 13) "nothing in the alive world makes sense, unless through the light of evolution."