Why are there animals on Earth and why are there animals in the world?

It didn't turn out to be, and then animals evolved, and you have to ask me how I got here, unless there is a time machine.

I'll come to this question.

Why are there animals in the world? There are many hypotheses about the origin of life in the natural sciences, and the one that is now widely recognized is the theory of the chemical origin of life, which divides the barren planet at the beginning of the formation of the earth into four stages from the emergence of primitive life.

Stage 1: The emergence of small organic molecules.

Hydrogen, ammonia, methane, water vapor, etc. react and combine freely in the natural environment of sunlight and lightning, and after a long time, organic small molecules appear. These small molecules contain a variety of amino acids as well as organic acids. Many of these new compounds, small molecules, were essential for primitive life.

The hypothesis of the first stage was also successfully implemented under laboratory conditions.

The second stage: the emergence of biological macromolecules.

Small molecule compounds are widely dispersed in the primordial ocean, and after long-term interactions, under appropriate conditions, primitive protein molecules are generated. The emergence of these protein molecules laid the foundation for the birth of primitive life in the future.

The third stage: the emergence of multimolecular systems.

Biological macromolecules, i.e., proteins, peptides, nucleic acids, polysaccharides, etc., can automatically aggregate into globular droplets in a specific solution. These aggregates have life phenomena such as synthesis, decomposition, and growth, but there is still no life.

Stage 4: The emergence of primitive life.

Aggregates form primitive life in marine environments, a process that cannot yet be verified in a laboratory setting. This process is also the most controversial, because protein macromolecules do not necessarily give birth to life. Theoretically, the emergence of protein macromolecules to the birth of primitive life is a random and long process, and the probability of this random appearance is unimaginably small.

Combining the above four stages, this process is now widely recognized by natural science researchers as the theory of the origin of biochemistry. It is the most accepted explanation for the question of why there are animals on Earth.

In the vast universe, from barrenness to the emergence of life, it is composed of atoms, and I have to say that our existence is a miracle in itself.

We currently can't explain why atoms are made up of life, and why life exists.

The history of our human science and technology development is only 300 years, and the universe has existed for 13 billion years, and we are too backward.

There are so many mysteries waiting to be uncovered.

Because it's not your problem.

All things are sentient beings!!

Because the earth was formed when the ** was large.

Because the earth can afford to raise it, and it is lively!

In the book of Genesis, God created all things, from the birds of the sky to the fish of the sea, and handed them over to man to manage, demonstrating God's authority and glory.

Isn't that stupid? Speaking of animals, we humans are also a kind of animals. If there are animals in the world, this is recommended that you find the relevant science and education films yourself**.

You should ask: why is there life on Earth?

This is biological evolution, and humans are also carbon-based organisms.

According to zoologists, there are about 1.5 million known species of animals on Earth.

Animals can be divided into two categories: vertebrates and invertebrates, vertebrates have a vertebral column composed of many vertebrae on the back of the body, and the individual is generally larger; Invertebrates have no vertebral columns, and most of them are small, but they are diverse, accounting for more than 90 of the entire animal population. For example, insects such as flies, mosquitoes, grasshoppers, butterflies, etc., are invertebrates. Vertebrates can be divided into five major groups: fish, amphibians, reptiles, birds and mammals.

Fish are the largest group of vertebrates, with a total of 25,000 to 30,000 species including marine fish and freshwater fish, such as carp and yellow croaker. There are more than 2,000 species of amphibians, such as frogs. There are more than 3,000 species of reptiles, such as snakes, turtles, crocodiles, etc.

There are 9,000 species of birds, such as pigeons, sparrows. There are more than 4,500 species of mammals, such as horses, cows, lions, tigers, etc. There are still many species of animals in the world that have not yet been discovered.

There are several conditions for the production of life.

1.necessary constituent substances. There must be carbon, hydrogen, oxygen, nitrogen and other elements of life. At the same time, it should also be noted that living matter is transformed from simple organic matter, and the production of organic matter lays a direct material foundation for life.

2.Moderate light and heat. The meaning of light and heat is, first and foremost, the source of energy for life activities.

Light plays an extremely important role in the conversion of inorganic matter into organic matter. Moderate light and heat produce the right temperature, which of course ensures that the chemical bonds of the carbon atoms are not broken and that biological processes are carried out normally.

3.Liquid water. Water exists in a liquid state at a suitable temperature. Water is an absolutely indispensable component of living organisms, and it is also an important medium for life activities, and some minerals required by living organisms come from water.

4.Atmosphere. A primordial atmosphere similar to that on Earth is far from enough to ultimately determine the existence of life.

This atmosphere can be synthesized by ultraviolet irradiation or electric sparks, but because it lacks enough oxygen, it cannot protect life from meteorites, the lack of ozone layer does not protect life from ultraviolet damage, and it does not have the appropriate components to protect the heat on the planet's surface. An atmosphere suitable for living beings to breathe is essential for the existence of life.

5.The above conditions are maintained for a long time. So that life has a process of generation, development, and evolution. Otherwise, even if life is generated, it will be short-lived, and there will be no real existence.

Plants come first. According to Darwin's principle of biological evolution, living things develop from the lower to the higher.

But it is not that animals are made of plants, there are all kinds of organisms on the earth, not only animals and plants, but also other microorganisms.

Different organisms all come from the same ancestor, and later all kinds of life forms are differentiated under the action of different environments.

The different differentiation of plants and animals occurs in the early stage, therefore, there is no necessary connection between the formation of them.