I believe many friends know that, except for a few anaerobic organisms, life on earth basically needs oxygen to breathe and survive. And the oxygen content on the earth does not always remain the same, but in the long life years, it has shown a sharp increase to a continuous decline, and finally maintained at about 21% of the current.
In the early days when no life was born 4 billion years ago, the earth’s oxygen content was very scarce, and later life was born in the ocean. At this time, life’s demand for oxygen is very small, which means that these organisms are basically anaerobic. biological. But over time, a particularly domineering creature appeared in the ocean, that is, cyanobacteria.
Cyanobacteria have a very powerful function of releasing oxygen. The emergence of a large number of cyanobacteria in the ocean has also caused the earth’s oxygen content to increase sharply. In the early earth environment, the highest oxygen content reached 40%. The environment with high oxygen content directly affects the evolution and evolution of the earth’s organisms. The most obvious thing is that the organisms at that time were very huge, whether they were marine organisms or terrestrial organisms, they all existed as giants.
The early earth had an era of giant insects, that is, the period when insects dominated the earth. In the eyes of modern people, insects can be said to be the life at the bottom of the biological chain. They are basically very small, but in the era of giant insects hundreds of millions of years ago, insects were very large, and ordinary dragonflies could reach one meter in length. , And the centipede’s body has reached a length of three meters.
The main reason why insects grow so huge is that the atmospheric oxygen content at that time was too high, which created the time when insects dominated. Later, with the continuous emergence of five mass extinctions, the oxygen content of the earth also continued to decrease with each ecological upheaval.
With the fifth mass extinction, after the end of the dinosaur era, the era of giant creatures is also over. The organisms that reappeared in the future are also shrinking. The reason for this change is related to the continuous decrease in the oxygen content of the earth. Since the end of the fifth mass extinction, the earth’s oxygen content has basically remained at about 21%.
Stable oxygen content plays a vital role in the ecology of the earth, especially the evolution and evolution of life. Some people may have said, why should the earth’s oxygen content be maintained at about 21%? What are the consequences of higher oxygen levels?
The stability of oxygen content is very important. It can be said that without this long period of stability, there would be basically no birth of human beings. We must know that in the long billions of years of life on earth, there have been many hegemonic life periods. But none of those creatures have evolved into intelligent creatures, but why only humans did it?
For human beings to become intelligent life, many people may put forward various answers. But in the editor’s opinion, one of the important reasons is that the earth’s oxygen content has dropped to the perfect position of 21%, and it has remained stable at this position until now. 21% oxygen content may be very important to mammals, and it can promote faster and more perfect evolutionary evolution of mammals.
This can be seen from the sensitivity of humans to oxygen. For humans, when the oxygen concentration is lower than 19.5%, it is considered hypoxic, and when the oxygen concentration is higher than 23.6%, it is considered to be oxygen-rich, which will cause the human body. Certain destructive effects. Only with fluctuations within a small range of about 21% can the human body be able to maintain a healthy state.
It is not only humans who are so sensitive to 21% oxygen, but most other mammals are the same. It can be seen that after the extinction of dinosaurs 65 million years ago, the rapid rise of mammals is closely related to the 21% oxygen content. Human beings can later realize the evolutionary evolution of wisdom, which may also have an important relationship with this 21% oxygen content.
If the earth’s oxygen content increases, the impact on mammals will be huge, especially for humans. We all know that apart from intelligence, human beings are actually relatively poor in physical fitness, far from being able to compare with many mammals. In fact, oxygen is a toxic substance, and the 21% content of oxygen just makes it impossible for oxygen to cause any harm to humans. This is a state of equilibrium between the human body and oxygen.
If this balance is broken, then oxygen will become a poisonous gas, which will cause harm to the human body. We all know that oxygen poisoning is actually the harm caused by excessive oxygen content. Therefore, higher oxygen content is a disaster for humans, and it is also not a good thing for other mammals.
We can even say that if the earth’s oxygen content rises sharply in a short period of time, then the earth’s ecosystem will undergo drastic changes. At that time, it is possible that the sixth mass extinction will come. So, if the oxygen content of the earth is slowly increasing after hundreds of thousands or millions of years, will it not have a catastrophic impact on mankind?
If the increase in oxygen content takes a long time to achieve, then there will be enough time for the earth’s organisms to adapt, and the ecosystem will have enough time to adjust. At this time, humans will gradually adapt to the ever-increasing oxygen-containing environment over the long years, but even so, the increase in the oxygen content of the earth will still not be good news for humans.
It is necessary to know that the slow increase in oxygen content may completely change the existing biosphere model. The creatures at the bottom of the past may become dominant again, such as very small insects. Once the oxygen content of the earth continues to increase, the shape of the insects will continue to change. Big. In the earth’s biosphere, insects are the most numerous, and their reproduction ability is beyond the reach of other creatures.
The main reason why insects cannot pose too much threat to other creatures is that their size is too small. But if the size of insects increases dozens of times or even hundreds of times, it will be a disaster for other creatures, especially for mammals, it will be a devastating disaster.
The environment with high oxygen content will not have much impact on the body shape of mammals. How big a tiger is now, how big it will still be in a higher oxygen environment, and the body shape will not change much. But the impact of insects is very big. Imagine that when the size of centipedes reaches about three meters, tigers and lions are only their food, and the same is true for other mammals.
At that time, although human beings were intelligent beings with the help of science and technology, we might still not be able to gain a decisive advantage in the face of a terrifying number of insects. The wild may become a dangerous area for humans, and even some primitive forests may become forbidden areas for humans.
It can be seen that the current 21% oxygen environment is so important to human beings, then can this oxygen content be maintained in the future? It may not be an easy task. It is important to know that the ecological environment of the earth will not remain unchanged. Once the ecological environment changes drastically, it is possible that the oxygen content of the atmosphere will also change drastically. In order to survive the ecological upheaval in the future, we can only rely on stronger scientific and technological forces. Therefore, the rapid development of science and technology is the hope for human beings to continue to survive.