Only 2.3 billion years ago, the air surrounding the Earth contained no oxygen at all. For the then primitive forms of life, this circumstance was a real gift.

Single-celled bacteria that lived in the primitive ocean did not need oxygen to sustain their life. Then something happened.

How did oxygen appear on Earth?

Scientists believe that as they developed, some bacteria "learned" to extract hydrogen from water. It is known that water is a combination of hydrogen and oxygen, therefore, the by-product of the hydrogen extraction reaction was the formation of oxygen, its release into water, and then into the atmosphere.

Some organisms over time adapted to live in an atmosphere with a new gas. The body has found a way to harness the destructive energy of oxygen and use it to control the breakdown of nutrients, which releases energy that the body uses to sustain itself.

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Earth collisions with meteorites

This way of applying oxygen is called breathing, which we use daily, and sow the day. Breathing is a way to ward off the oxygen threat: it made possible the development on Earth of larger organisms - multicellular ones, which already have a complex structure. After all, it was thanks to the appearance of breath that evolution gave birth to man.

Where did oxygen come from on earth?

Over the millions of years that have passed, the amount of oxygen on earth has increased from 0.2 percent to the current 21 percent of the atmosphere. But bacteria in the oceans are not the only ones to blame for the increase in oxygen in the atmosphere. Scientists believe that colliding continents were another source of oxygen. In their opinion, during the collision, and then during the subsequent divergence of the continents, large amounts of oxygen were released into the atmosphere.

For centuries, scientists have been debating about the real source of oxygen on Earth. According to preliminary data, the first half of the life of the planet Earth was generally without oxygen. Most scientists put forward the theory that 2.4 billion years ago, oxygen on Earth was negligible. Our atmosphere was filled with oxygen gradually.

How did oxygen appear on Earth? It is believed that the main source of oxygen on Earth is cyanobacteria. It is a photosynthetic microbe that generates oxygen. And thanks to cyanobacteria, there was a sharp jump in the oxygen content in the atmosphere. But when and why these microbes appeared is not yet fully known. Also, it is not yet fully understood how exactly the process of filling the Earth's atmosphere with oxygen took place. It is known that this was a combination of a sharp global cooling, the emergence of new species, and the emergence of new mineral rocks. According to Dominic Papinet (specialist at the Carnegie Institution, Washington), the doctrine is not yet able to clearly define what was the cause and what was the effect. A lot happened almost simultaneously and for this reason there are so many different inconsistencies and contradictions. To further clarify the geological side of this issue, Dominique Papinet studies in detail the process of the formation of iron, as well as sedimentary rocks that form at the very bottom of the ancient seas.

His research focuses on specific minerals. These minerals are contained precisely in the formations of iron, and they may well be associated with the emergence of the life of ancient microbes and their death. Iron minerals, which are found quite at the bottom of the seas, are the largest source of iron ore. And it's not just a material for making steel. According to geologists, it is in it that a rich history of the origin of life on planet Earth is hidden.

And the origin of this source is still a big mystery. Scientists have found that for its formation the help of special microelements is needed, but, however, it is still unknown which ones. These marine organisms are simple unicellular, but unfortunately they did not leave any information behind. And researchers cannot now find out exactly what they were and what they were.

It is believed that the builder of such iron minerals was precisely cyanobacteria. The oxygen that came out of it oxidized the iron in the seas and oceans long before the great oxygen explosion occurred. But one thing remains unclear. Cyanobacteria appeared on planet Earth long before the accumulation of oxygen. It turns out that hundreds of millions of years passed before our atmosphere was filled with oxygen?

Perhaps the answer lies in the complex intertwining of biology and geology. The oxygen exhaled by the cyanobacterium could be broken down by methane. When these two gases interact, water and carbon dioxide are formed. Scientists noted that oxygen cannot accumulate in an environment rich in methane. Methanogens produced methane and blocked all paths to the accumulation of oxygen on the planet and also heated the Earth as a result of the greenhouse effect. And after the planet Earth was filled with oxygen, the number of these organisms decreased.

In which they experimentally confirm their hypothesis explaining the appearance of oxygen of non-plant origin on Earth.

Almost all living things use oxygen to breathe. Without delving into the physics and chemistry of the processes of cellular respiration, let's say that the choice of evolution fell on oxygen because of its high ability to oxidize, that is, to easily attach an extra electron. An electron enters the electric transport chain from NADH or FADH 2 travels through it, and everything ends with the synthesis of an ATP molecule - the material equivalent of stored energy and the addition of an electron to oxygen. This whole reaction becomes possible because this electron transfer is energetically favorable, and this is partly due to the properties of oxygen.

When life was born on Earth, there was practically no oxygen in the atmosphere, just as there is none on Venus or Mars today. Ancient bacteria were forced to use other oxidizing agents, often energetically less favorable, but available. NO 3 - , NO 2 - , Fe 3+ , fumarate and dimethyl sulfoxide, used by some species of bacteria, have a higher redox potential and are less beneficial as oxidizing agents. Many bacteria using one of these oxidizers are also capable of oxygen respiration. In the presence of oxygen, they breathe it (this is more profitable), and when there is no oxygen, they breathe their other oxidizing agent (you must somehow). Sulfur-containing oxidants (S, SO 4 -) have a lower redox potential. This, however, makes the oxygen toxic to the respective micro-organisms, and in an oxygen-containing atmosphere they die. In more highly organized life forms, anaerobic respiration is rare and almost never serves as the main source of energy.

Could highly developed life forms use other than oxygen as an oxidizing agent? Oxygen as an oxidizing agent is energetically more favorable than most other substrates (the lower the redox potential of the oxidizing agent, the more energy is released when an electron passes through the electric transport chain). This means that oxygen-breathing organisms had a more efficient metabolism and were better adapted. From an energy point of view, sulfur-containing substrates are also quite beneficial. The problem, however, is that the owners of this type of breathing die in the presence of oxygen. It is still not entirely clear why this is happening. That is, if oxygen had not appeared in the Earth's atmosphere, over time, the owners of sulfate respiration could have evolved further. But oxygen appeared, and they had to go to "reservations" where oxygen is not supplied.

The question is where did the oxygen come from. Today, the Earth's atmosphere contains approximately 20% oxygen. In such huge quantities, it is released by photosynthetic plants, mainly trees and algae. But photosynthetic plants themselves now mostly breathe oxygen. In order for the mutations that allow you to breathe oxygen to become fixed in the course of evolution, this must be beneficial, which means that there must be oxygen. In large quantities, oxygen on Earth appeared thanks to cyanobacteria. These are nitrogen-fixing bacteria that can photosynthesize. That is, massively oxygen appeared on Earth as a by-product of photosynthesis. This event is called " Oxygen catastrophe", apparently, for the scale of the consequences.

But the question of whether there was oxygen before that remains open. Over the past 40 years, they have become more and more confident in saying that oxygen existed even before the Oxygen Catastrophe, and now the possibility of its existence has been confirmed experimentally.

Until now, only one way of the origin of molecular oxygen under the conditions of that time was known. It consists of two stages: the dissociation of carbon dioxide under the influence of solar ultraviolet into carbon monoxide and atomic oxygen, and the reaction of two oxygen atoms, requiring a third participant: the atoms combine into a molecule, and the carrier (M) carries away excess energy.

CO 2 + hν(UV) → CO + O

O+O+M → O 2 + M

However, the calculations, and then the experiment, carried out by the authors of the article under discussion showed that oxygen can be formed from carbon dioxide under the action of ultraviolet in one step:

CO 2 + hν(UV) → C+O 2

In the experiment, a laser with a wavelength of 200 nm was used; light with such a wavelength is usually absorbed by the atmosphere, so the reaction should have taken place in its upper layers. Even now, when the content of carbon dioxide in the atmosphere is increasing, such a reaction can occur in the upper layers of the Earth's atmosphere, and maybe in the atmospheres of other planets.

Developments

The first part of the history of the Earth's existence was deprived of oxygen, during this period there was no life on it. Debates are still ongoing as to whether who were the main biological players on an anoxic Earth, but most researchers are looking for the roots of this issue in the oldest sedimentary rocks.

Most scientists assume that the amount of oxygen on Earth was very small about 2.4 billion years ago, until the atmosphere was filled with oxygen. This spike in atmospheric oxygen was due to cyanobacteria, a photosynthetic microbe that exhales oxygen.

How and when microbes exhaling oxygen appeared is still not determined due to the fact that filling the atmosphere with oxygen was a complex combination of global cooling, the emergence of mineral rocks, and the emergence of new species.

"We are not yet able to determine what is the cause and what is the effect," said Dominique Papinet, a specialist at the Washington Carnegie Institution. "Many things happened almost at the same time, so there are so many ambiguities." In order to help understand the geological side of the issue Papinet studies the range of iron and sedimentary formations that form at the bottom of ancient seas.

Papinet's research focuses on specific minerals found in iron formations that may be linked to the life and death of ancient microbes. Iron minerals found deep at the bottom of the seas are the largest source of iron ore. However, this source is more than just a material for making steel. Geologists study them, since they have a rich history associated with the origin of life on Earth.

However, their origin is a very big mystery. The most recent conclusion that most scientists have come to is that the help of special trace elements is needed for their formation, unfortunately, which ones have not yet been identified. These simple one-celled sea creatures left nothing which could help researchers recreate their image and understand what they are.

It is possible that the builder of these iron minerals was cyanobacteria, and oxygen from these bacteria caused the oxidation of iron in the seas and oceans even before the great oxygen explosion. In that case, why, if cyanobacteria actually appeared long before the accumulation of oxygen on Earth, did it take several hundred million years before the atmosphere was filled with oxygen?

Perhaps Papinet and his colleagues found the answer to the question in the form of a complex interweaving of biology and geology. Oxygen from cyanobacteria could be destroyed by methane. The interaction of these two gases produces carbon dioxide and water. They also noted that oxygen cannot accumulate in a methane-rich environment.

Methane originated from bacteria called methanogens, as a result of the absorption of carbon dioxide and hydrogen by these bacteria, and the appearance of methane was. Under this scenario, methanogens and cyanobacteria dominated the ancient seas and oceans, but the amount of methanogens was greater, so when they produced methane, it blocked the path of oxygen to accumulate, and also warmed the planet as a result of the greenhouse effect. But after the Earth became "oxygenous", the number of these organisms was sharply reduced, which allowed the atmosphere to fill with this gas.

We all know from school that we breathe oxygen. Or air containing oxygen. Since that time, we have known that plants produce oxygen, and we emit carbon dioxide. So it is, but does it affect the atmosphere of the planet in any way?

Or we simply slightly transfer gas-containing air from one state to another, which mixes with the air ocean, restoring the original balance of the air mixture inherent in the earth's atmosphere at the moment, without changing anything in the general surrounding air space.

Oxygen and water are a single water-air system at this stage of the evolution of our planet, which we are not able to influence.

In the distant past, there were gigantic fires when the forests of entire continents burned down. Gas escaping from the bowels was burning, oil was gushing out. Peatlands and coal seams burned out. At the same time, oxygen was consumed in large quantities for combustion.

Everything that we humans burn in our entire conscious history is nothing compared to a continental fire! Compared to the burning oil sea, which has been burning for three years! And it will still burn for two years until it burns out completely. What about oxygen? It is in the air, and keeps the sea of ​​oil burning. In addition, in the presence of water on the planet, when the level of oxygen decreases, the process of its active restoration to its original level is launched.

Rotting plants

Trees produce oxygen, but they also consume it during respiration and decay of fallen leaves. A tree produces a certain amount of oxygen during its life. But after death, the rotting of a tree trunk will take as much oxygen, if not more, than it has produced in its lifetime.

Let's assume that oxygen is produced by plants.

We have forests growing on the globe in North and South America, in Siberia in Africa, and in India. That is, locally, not everywhere. There are no trees in the mountains, in the deserts, in the steppes, in the snow-covered North and South Poles. If you look at the map, you get several small areas of land where there are forests, which, as it were, are the “lungs” of our planet. Let's say.

We know that there is a water cycle in nature. There are no questions here. We know that there are warm and cold air currents. There are warm and cold currents in the oceans. All of them significantly affect the climate of the planet.

But for some reason no one talks about the oxygen cycle in nature. And actually why? After all, where there are forests, there should be more oxygen. And where there are no forests, there must be a lack of oxygen. Logically, there should be air "oxygen" corridors along which it would move around the planet along with the wind. And there must be areas where oxygen does not reach. But we were never issued a storm warning, say, of a 10% drop in oxygen levels in the Gobi desert, due to the increased east wind. A reduced percentage of oxygen occurs only on hills, the higher the mountain, the less oxygen.

Another amazing moment. Winter. All North America and Eurasia under the snow. In October, all plants fall asleep and only in April the first leaves bloom. All coniferous trees also sleep, and they do not emit any oxygen for 6 whole months! And we do not notice it! On the contrary, we are talking about some kind of winter freshness! Well, what freshness without oxygen!

The middle of the Pacific Ocean - 5 thousand kilometers to the nearest forest, but how easy it is to breathe!

The conclusion suggests itself: Air currents on the planet move a huge amount of cold and warm air, which changes the climate at the same latitude by several tens of degrees! But the level of oxygen in the air remains unchanged throughout the planet and is 21%. And so - as oxygen is produced by forests, which are located on 15-20% of the globe, then such a uniform distribution of oxygen is simply impossible. The theory of oxygen production by plants for the entire atmosphere of the Earth is untenable.

So where does oxygen come from?

The previous Metagalaxy, shrinking, absorbs all matter, including water, and all gases together with oxygen. A swarm of black holes merges into a single black hole. There is a "tamping" of matter by its own mass, or "Destruction of Matter".

All the matter of the Metagalaxy gathered into a single Ball, the so-called Pro-Maternal Ball, with the most gigantic density of matter and with the highest level of compression. (See the article "The Origin of Our Universe")

The process of “Origination of Matter” or a new one, our Metagalaxy, has started.

Evolutionary chain of Arising Matter:

Pro-Mother Ball - explosion - Nameless Ball - explosion - Ball Quasar - explosion - Ball Galaxy - explosion - Ball Star - outburst - Ball Planet - outburst - Ball Planet satellite.

The core of our planet is a part of the Pro-Mother Sphere. Only in the process of evolution of the New (our) Metagalaxy, the core of the Earth has the lowest density of matter and the lowest level of compression, in relation to the Pro-Mother Sphere.

Thus, the core of the Earth contains all the elements of the previous Metagalaxy.

So, after Mars, the Sun once again ejected part of its core. The core flashed with bright light, and began to move around the Sun in an elongated elliptical orbit, irradiating all the planets of the solar system with super powerful radiation.

This is how the new star Earth was born.

Soon this star went out, turning into a planet, and cooling processes began on it.

An outpouring of magma, the first solidified crust, and a huge outgassing.

And since the core contains all the elements of the previous Metagalaxy, the escaping gases also contained water. The original water was super-heavy, with super-heavy oxygen, such water had high radioactivity, but in the process of evolution it became what we know it to be. In the gas of a modern volcano, water is also present, only in much smaller quantities.

Well, where there is water, there is free oxygen. Where is oxygen released from water? In the oceans, maybe. But judging by the uniform distribution of oxygen in the earth's atmosphere, oxygen is released from water vapor in the upper atmosphere, under the influence of sunlight, and falls evenly on the entire planet, regardless of whether it is the equator or the pole.