What role do microorganisms play in nature?

The ocean has always given people a mysterious feeling. The ocean covers more than 70% of the earth's surface and is the main driving force of weather and climate. A slight fluctuation in ocean temperature may cause drastic changes in weather and climate around the world. However, some netizens said, if all creatures below 3,000 meters in the ocean become extinct, what impact will it have on us? Apart from anything else, the ocean will be filled with corpses of various animals and plants, and then cause a global disaster... Today, let's talk about the topic of biology.

01. How big is the range of organisms?

In fact, I think when people talk about this issue, they must not have considered how huge the concept of biology is. Turtles are of course biological, but flowers and plants are also biological, and the larger biological group is microorganisms such as bacteria and fungi. One of the important responsibilities of these organisms is to decompose various "remains" or "biological fragments" in nature, such as fallen leaves, fallen petals, and whale falls (which are said to be highly praised by literary youth), etc.

If there were no microbial decomposers, there would naturally be big problems.

The most typical example is that when plants landed on the earth, they were busy with photosynthesis, which caused the oxygen content of the earth to rise rapidly, but at the same time it caused the carbon dioxide in nature to be almost gone after being breathed in by plants (photosynthesis absorbs carbon dioxide and converts it into oxygen). Plants began to die in large numbers, and the earth was filled with plant corpses.

If you traveled back to that time, you would see that the Earth was a lifeless place. Fortunately, at this time, microorganisms on Earth began to evolve on a large scale, mainly fungi, which could decompose plant remains in large quantities and produce carbon dioxide, thus restoring the cycle, so that the oxygen content of the Earth could be maintained within a relatively constant range. This was the first major crisis in the plant kingdom.

02. Let’s talk about photosynthesis again

Let's review the principle of plant photosynthesis: light + water + carbon dioxide = glucose + oxygen

In this formula, light comes from the sun, water is abundant on the earth, and a core limiting factor, carbon dioxide, becomes a rope around the neck of plants.

At that time, plants absorbed carbon dioxide crazily, and as a result, **the earth ran out of carbon dioxide!!! **What the hell, not enough carbon dioxide? Yes, seeing the greenhouse effect today, don’t you find it weird?

But the fact is that there is not enough carbon dioxide on Earth for photosynthesis. Plants rely on carbon dioxide to survive. Once carbon dioxide is gone, plants cannot survive, and thus the first crisis on Earth was born. Countless plants died.

At this time, some plants began to look for new paths, and leaves began to appear on the stage ( remember the core of evolution, mutation is random, selection is directional. Back here, leaves appear randomly, and low concentration of carbon dioxide is just a natural selection process, there is no direct cause and effect relationship between the two ) In addition, the picture here is angiosperms, which appeared in the Jurassic period, and earlier was gymnosperms. Algae-moss-ferns-gymnosperms-angiosperms

The appearance of leaves is a great page in the history of plant evolution. Because of the appearance of leaves, plants no longer rely on trunks and branches for photosynthesis, but use leaves for photosynthesis.

The leaves of plants increase the range of photosynthesis by millions of times , and the leaves can better utilize the thin carbon dioxide in the air for photosynthesis.

So, the plant survived.

03. How to solve the problem of carbon dioxide?

Although the plants survived, the tragedy was still unfolding. Because the appearance of leaves allowed the plants to absorb more carbon dioxide, they did survive, but in essence, the carbon dioxide on Earth continued to decrease, and it was decreasing at an accelerated rate (absorbing more vigorously). If there was no new source of carbon dioxide, then all the plants would die, or they would switch to other gases, such as nitrogen fixation.

However, at this time, fungi saved the earth. You can refer to the works of the great Pavlov for this content.

Perhaps in the beginning, no one thought about decomposing plant fibers, not even animals. A large number of plant corpses would be a garbage paradise. Until one day, the earth could no longer bear it. Fungi began to show their strength. They decomposed plants, making the carbon cycle flow successfully, filling in the last missing link.

This is today's green world.