Alpha Omega

Numerous studies in the various branches of science have revealed that the larger and more massive outer planets retained all of the gases of their original atmospheres, which are sometimes called primitive atmospheres. While the smaller and less massive inner planets, satellites and asteroids lost all, or nearly all, of their initial atmospheres. For example, the atmosphere on Mars is composed of about 95% carbon dioxide. Most of the remaining gases of Mars all escaped the planet’s gravitational attraction.

On Venus and earth the lighter gases, such as hydrogen and helium, escaped but the heavier gases, such as ammonia, methane, water vapor and carbon dioxide, were retained. The earth obtained its atmosphere from violent volcanic eruptions; it escaped through cracks in the surface; or it bubbled to the surface of hot springs. This is known as outgassing. The earth’s primordial atmosphere continued to escape from the earth’s interior in this fashion for thousands of years, adding to the remnants of the atmospheric gases that had not earlier escaped the earth’s gravitational attraction.

Scientists are not quite sure exactly what made up the chemical composition of the earth’s primary atmosphere. What is known is that it was dominated by the elements carbon (C), hydrogen (H), oxygen (O) and nitrogen (N), with lesser amounts of the chemicals phosphorus (P) and sulfur (S). What is not known is the exact chemical make-up of the early atmosphere. The scientists can only speculate upon its make-up.

Present day volcanoes expel large quantities of carbon dioxide (CO₂), with smaller amounts of free hydrogen (H₂), oxygen (O₂), nitrogen (N₂), water vapor (H₂O), ammonia (NH₃) and methane (CH₄) with traces of phosphorus (P) and sulfur (S). Since the atmospheres of Venus and Mars are today dominated by carbon dioxide, this is persuasive evidence that these chemical compositions were those that composed the earth’s primitive atmosphere. That is, earth’s original atmosphere was one dominated by carbon dioxide with lesser amounts of the other chemicals.

However, laboratory experiments have proven that the chemical precursors of life form far more easily in an atmosphere dominated by ammonia, methane and water vapor with lesser amounts of carbon dioxide, free nitrogen, hydrogen and oxygen. This has led many scientists to believe that this latter was the composition of the earth’s early atmosphere.

But whether or not the earth’s primitive atmosphere was dominated by carbon dioxide or dominated by ammonia, methane, and water vapor is not important at this time to this treatise. For even if it were dominated by the latter chemical compositions, the atmosphere would have eventually been converted to carbon dioxide through a process called photodissociation.

Ultraviolet light coming from the Sun would have broken up the water vapor (H₂O) molecules. Once the molecules were broken apart, the hydrogen (H) would have escaped the earth’s gravitational attraction and the oxygen (O₂) would have combined either with methane (CH₄) to form carbon dioxide (CO₂) and water vapor or with ammonia (NH₃) to form free nitrogen (N₂) and more water vapor. Slowly and steadily, over the ages, the atmosphere would have converted from ammonia, methane and water vapor to free nitrogen, carbon dioxide and water vapor.

When free oxygen began to collect in the upper atmosphere an ozone (O₃) layer was formed. When enough ozone had accumulated, photodissociation was halted as the ozonosphere blocks out the ultraviolet rays of the Sun. One should note that if were it not for this ozone layer protecting the earth all life on this planet would soon die.

One may think of the ozonosphere as a coating of suntan lotion for the earth. That is, enough ultraviolet radiation does seep through to give a person a sunburn after staying out too long, unprotected on a cloudless, summer day.

After the development of the ozonosphere the water vapor began condensing into rain. The rain drained into a giant ocean. The German meteorologist Alfred Wegener (1880 - 1930) named this ocean Panthalassa; it is also known as the Paleo-Tethys Ocean. This is not to insinuate that there was an ancient world wide monsoon that filled this ocean plus the other seas and lakes of the ancient earth. There was probably even some rain while the ozonosphere was in the process of developing!

Scientist are not sure how the earth obtained so much water. Most believe that it came from a combination of outgassing and icy comets. The latter striking the earth during the heavy bombardment phase of the solar system, 4.5 to 3.8 billion years ago. Some scientist have even suggested that the gigantic asteroid which struck the earth and created the moon was a large icy body similar to Europa, a Galilean Satellite of Jupiter, and that is the source of the water for all the oceans, seas and lakes of earth.

Exactly how the earth obtain a large body of liquid water is better left to the scientists to resolve. The important thing to note here is that coming down with the rain and filling this panthalassic ocean and the other primordial waters of earth were those chemical compounds from which the first life would eventually originate.

In 1953, Stanley Miller, then a graduate student at the University of Chicago working under chemist Harold Urey (1893 - 1981), performed the now famous Miller Experiment. Miller developed an apparatus for passing water vapor through a mixture of ammonia, methane and hydrogen. The student subjected it to electrical charges, allowed the mixture to condense into a liquid and then to collect in a receptacle. There it was then reheated in order to recycle the process again.

After allowing this to continue for several days Miller examined the mixture, which had become yellow. Several days after this it had become deep red and turbid. Further examination of the mixture showed that it contained amino acids, which are the essential building blocks of proteins.

Since 1953, other experiments similar to Miller’s have produced carbohydrates and nucleotides (the structural units of nucleic acids). Both of these are important constituents in the make-up of living cells. Thus, Miller helped pave the way in proving that some of the complex molecules that make-up living cells could have been produced in the earth’s primitive atmosphere, would then have come down with primordial rains and then accumulated in Panthalassa and the primordial seas and lakes.

Thus, the first steps in the long journey toward a living organism were taken some four and one-half billion years ago while the earth’s atmosphere and Paleo-Tethys Ocean were in the process of evolving.

As it was mentioned above, these first steps would have been accomplished easier in an atmosphere where oxygen (O) and carbon (C) were combined with hydrogen (H) to make water vapor (H₂O) and methane (CH₄) instead of with each other to make carbon dioxide (CO₂). During this time, as it was also noted, photodissociation would also have been converting the atmosphere into a secondary atmosphere dominated by nitrogen, carbon dioxide and water vapor. One can only conclude that the chemical precursors of life developed during the millennia it took for this conversion to take place.

Had carbon dioxide remained one of the dominating gases of earth’s atmosphere the overall temperature of the planet would have risen. This is because carbon dioxide absorbs the infrared radiation of the Sun during the day. If there is a cloudy night, then the accumulated heat of the day cannot escape. Thus, it is warmer on a cloudy night than on a clear night. It is this “greenhouse effect” that will cause the temperature of a planet to rise. On earth it would have risen so high that all the oceans, seas and lakes would have eventually evaporated and the earth would have been without life.

This is what happened on the planet Venus. The carbon dioxide atmosphere enshrouded the planet with massive clouds and prevented the infrared radiation from escaping. The temperature of Venus then began to rise. This prevented the water vapor from condensing into rain, which aids in returning the carbon dioxide to the crust as carbonate rock. Because water vapor also absorbs the infrared heat of the day, the greenhouse effect was enhanced and the overall temperature rose even further.

Eventually even any of the seas and lakes that Venus may have had were evaporated. Today the temperature on Venus is about +750° K (+477° C), far too hot to support any type of life. This was learned through the several Venera spacecraft landed on this planet by the Soviet Union and the Mariner and Pioneer spacecraft sent there by the United States.

However, the carbon dioxide had a different effect on the planet Mars. It is not as massive as the earth and was unable to retain a large atmosphere. Also, Mars, being further from the Sun, receives less solar radiation. What little water vapor that the planet was able to retain is frozen beneath the surface in permafrost and in the polar ice caps beneath sheets of frozen carbon dioxide. The remaining carbon dioxide of Mars is found in its thin atmosphere. Because the atmosphere is thin, most of the incoming solar radiation escapes the planet and much of the remaining radiation is absorbed by the carbon dioxide, leaving very little to warm the planet.

Thus, unlike Venus where the thick carbon dioxide clouds keep it a boiling cauldron, the thin carbon dioxide atmosphere on Mars keeps it an icy, wind swept wasteland, where temperatures reach -120° C (-196° F). This was learned through the two Viking spacecraft landed on this planet by the United States.

Whether or not Mars harbors microbial life is presently unknown. So far it has not been detected even though several space craft have been landed on the planet and placed in orbit above it, all searching for traces of either extinct life or actual living microbes. Scientists are not searching for more advanced life forms for they are sure such does not live on Mars, nor has it ever lived there.

However, on earth the carbon dioxide did not remain a dominating gas of the early atmosphere. Being neither too close nor too far away from the Sun, the earth receives a moderate amount of solar radiation and its climate is kept at an equilibrium. When the atmosphere was forming this enabled the carbon dioxide to dissolve with either rain water or with ocean water to produce a weak carbonic acid. This carbonic acid then began to react with minerals in the crust to form carbonates.

Moreover, living cells eventually developed the ability to breakdown water molecules. The hydrogen combined with atmospheric carbon dioxide to form molecules that make up the cell and the oxygen was released into the atmosphere. Thus, the carbon dioxide of the earth is broken down and hidden in the sediments and in living organisms. The chemical reactions and the photosynthetic actions of these ancient life forms produced still another change in the earth’s atmosphere.

It eventually altered the atmosphere from one of nitrogen and carbon dioxide to one of nitrogen and oxygen with only a small amount of carbon dioxide. This reduced the greenhouse effect and the earth retained its two unique possessions of an ocean of liquid water and an atmosphere of large amounts of free oxygen.

Studies have shown that the ancient seas and lakes of the earth were filled with the molecules essential to living organisms. This is why these bodies of water are often referred to as “organic soups.” This has led scientists to speculate on how the first self-duplicating organisms emerged from the nonliving building blocks mixed in this organic soup. Unfortunately there are a few difficulties associated with the emergence of living cells from nonliving chemicals, as it was a long and complicated process.

First of all, there is no evidence of this emergence of life from complex carbon molecules, either in fossils or in laboratory experimentation. Secondly, part of the problem comes in attempting to explain how relatively small, simple amino acids formed into large, complex protein molecules. Only on rare occasions do these linkages occur in open water.

Never-the-less, it does take place when groups of amino acids become heavily concentrated and partially dried. Some biologists have therefore speculated that the formation of large, complex protein molecules from small, simple amino acids occurred on beaches or small pools and other places that were periodically dried environments.

Finally, an even larger problem is trying to explain how these complex protein molecules became organized cells capable of self reproduction.

Chemists have done experiments and shown how, under limited conditions, organic compounds floating in water will frequently aggregate into spheroidal globules. These protein spherules are surrounded by a membrane that separates them from the organic soup in which they are suspended. But the chemical reactions that occur within even the simplest living organism are immensely more complex than the chemical reactions that take place among these assorted conglomerations of protein compounds.

Although the reactions are similar in kind they are different in degree. One may understand this better by contrasting it with the similarities in the oxidation process during flammable combustion and the oxidation process in cellular respiration, or the similarities in the oxidation process during cellular respiration and the rusting of a piece of iron. In one there is rapid oxidation, while in the other there is oxidation but on a much slower scale.

Again, the same is true with the chemical processes that take place among assorted protein spherules and living cells. The chemical reactions are similar in kind but different in degree.

There are two essential requirements for all living cells. First, they must have a continuous supply of structural materials for growth and repair. The building materials of living cells are carbon, hydrogen, oxygen and nitrogen. Autotrophs obtain most of their structural materials directly from carbon dioxide (CO₂) and water (H₂O), while heterotrophs must feed on autotrophs or other heterotrophs in order to obtain a fresh supply of structural materials. As one might have guessed, green plants make up most of the autotrophs, although some bacteria fall into this category, while animals, most bacteria and fungi are classified as heterotrophs.

The second major requirement of living cells is a continuous source of energy in order to organize their building materials. Here too, there are two major divisions. Most autotrophs and some forms of bacteria get their energy directly from the Sun. While animals, most bacteria and fungi obtain their energy requirements from the potential energy stored in carbohydrates, fats and proteins.

It is easy to see that bacteria have the distinction of filling all possible sources of structural materials and sources of energy requirements. Bacteria also have another unique characteristic. Along with cynobacteria (blue-green algae) they lack a chromosome bearing nucleus and they have an overall simpler make-up than other cells. Because of this uniqueness biologists classify bacteria and cynobacteria as prokaryote and all other life forms as eukaryote. Because of their more complex nature, it is generally assumed that the eukaryotes arose from a prokaryote thermophilic archaeabacteria, which is believed to have been the first form of life on earth.

The step from nonliving to living organism is a long and complicated one. However, a hazy description should provide one with an idea of what happened several billion years ago. First of all, the active and most abundant of the chemicals in the atmosphere began to form the organic acid groups and the amino groups. (It had to be the active and most abundant elements because life could not be composed of the inert elements or the relatively rare earth elements, as such would lose out in a competition for dominance.)

The acid groups and the amino groups then combined to form the amino acids; chains of these are the structural units of proteins. This is one of the primary food sources of living cells. In addition to the amino acids, deoxyribose and ribose sugars were also formed. Some of the sugars formed carbohydrates, the energy source of most heterotrophs, while other sugars combined with purines, pyrimidines, and phosphates to form nucleotides. It is unions of nucleotides that form nucleic acid.

One should note that all these chemical actions were generated by the solar radiation coming from the Sun. All these compounds then collected in pools, shallow seas and the waters of Panthalassa in aggregates of protein spherules and nucleic acids. However, some scientists believe that the Sun shone with only a percent of its present brightness. These scientists believe that the vast majority of these chemical reactions were generated by the heat produced in volcanic hot springs on the bottoms of the primordial seas and lakes. These seafloor geysers spewed out superheated fluids that were permeated with energy rich compounds.

Four and a half billion years ago, the scalding temperatures enabled chemicals to join together in a multitude of ways, creating new molecules. These seafloor springs cooked the sterile, primeval seas and lakes and powered the chemical reactions scientists believe were necessary for evolving the precursors of the first living organisms, the protein spherules.

But whether the precursors to the first living organisms were combined through the actions of the ultraviolet light of the Sun or through the heat of volcanoes is not important to this book. It is far better to let the scientists who are more capable of answering this question to solve this dilemma. The point here is that the chemical reactions necessary to produce the precursors to life were accomplished four and one-half billion years ago while the atmosphere was forming and the chemicals involved were coming down with the primordial rains and filling the ancient seas and lakes, where they underwent further changes.

Finally, after many millennia, the key step came. This was the formation of a ribonucleic acid (RNA) molecule capable of replicating itself. From this self replicating molecule came the first living organism: a very simple, delicate prokaryotic heterotroph that used preformed non-biological carbon compounds (nearby protein spherules that were surrounding the life form) as both an energy source and structural material.

Like a butterfly fresh from the cocoon — after resting on a leaf waiting for the Sun to dry its wings — then suddenly flying about, randomly sampling the sweet nectar from each nearby flower, this microscopic, unicellular organism came to life and began to consume near-by carbon compounds. Being a benthonic organism and neither a deposit nor a sediment feeder, it just “absorbed” nutrient chemicals into itself. It then began to multiply by fission and populate the waters of the earth. It is from here that all life on earth has originated.

Before continuing, one should note that most scientists today believe that the deoxyribonucleic acid (DNA) molecule evolved from the RNA molecule.

Scientists do not know what the exact environmental conditions were that prevailed on the earth over four and one-half billion years ago. Nor do they know what influence this had on the actual emergence of the first life. Scientists do know that conditions were very inhospitable for most types of life in existence today. They know that prior to about 4.5 billion years ago the earth was inhospitable to all life. They know that the earth was still being heavily bombarded by asteroids and meteorites until about 3.8 billion years ago. Scientists know that volcanoes and geysers were larger, more prevalent and more active then than they are now.

The atmosphere was filled with gases that would poison any animal alive today. This is why some scientists speculate that the first living organism (or organisms) just evolved on their own during this time. They may be right. However, at this time it does not seem possible for a nonliving environment to bring forth a living cell. All present scientific knowledge proclaims that life must be biogenetic.

Those biologists and other scientists of this world who have an interest in the origin of the earliest life forms have not figured out just how these organisms did come to life. At present, it is an enigma of modern science as to how life arose from the sterile, chaotic medium of the primordial seas. For nothing that even remotely resembles life’s processes can be detected in the behavior of the elements or in their chemical properties.

It is a law of natural science, discovered by Louis Pasteur (1822 - 1875), that living organisms can only come from other living organisms and that like can only produce like. Pasteur proved that there is no such thing as abiogenesis or spontaneous generation. Therefore, there is a very good possibility that the scientists may never be able to produce a living cell from a nonliving molecule.

Life cannot rise simply from the workings of physical and chemical laws. Life must be biogenetic! Nor does it seem possible for a person to hypothesis that the first living organism obtained its life from nonliving electrical charges or some other nonliving energy source of the ancient earth. That is just restating the absurdity of abiogenesis. All living organisms, which without a doubt includes the first life form — or forms — must come from a living entity.

Meteorites have been found that contain the chemical precursors to life and such chemicals have also been found on the other planets, asteroids and satellites. This has led some scientists to speculate that the first life arrived here on earth from outer space! Although it seems highly doubtful that life arrived here from another planet, even if such does somehow prove to be true, it would still not answer the question of the ultimate origin for all life.

As with the question about the ultimate origin for the universe in the first chapter, one is still left with a question that science does not seem to be able to answer. One can only ask: From where then did the first living organism obtain its life? If the first living organism could not have gotten its start from the environment and at present there is no evidence that it could have, then it appears that one must search for a life before life existed. This is because life must be biogenetic.

The only logical source for such a first life is an Eternal Living Being or an Eternal Omnipotent Creator and this is philosophical and theological in nature, not scientific.

The question of where the first living organism obtained its life will be answered later on. For now it seems wise to “put the question on the shelf” for later investigation, along with the question about the origin of the primeval star and continue with the creation of the earth and the ascent of Homo animus.

Alpha Omega

Life Support Systems