Due to the consumption of earth's resources by microbial systems for more than three billion years, a huge amount of carbon dioxide has accumulated in the earth's atmosphere.

At this time, cyanobacteria with photosynthetic capabilities that can consume carbon dioxide and generate oxygen appear.

The emergence of large amounts of oxygen paved the way for Earth's organisms to move from single-cell organisms to more complex multi-cell biological structures.

After that, life on earth began to explode.

Right under Zhou You's eyes, creatures began to iterate and evolve rapidly.

This is the Cambrian period.

The Cambrian Period lasted tens of millions of years.

During this period, trilobites appeared.

The concept of male and female emerged.

Creatures began to have heads, legs and other organs.

Creatures have even evolved photoreceptors, the most primitive eyes.

Life on Earth has seen the light.

The traveling eyes also followed important mutations time and time again in the history of Earth's biology, personally witnessing the germination, development, and then complete birth or destruction of each new species.

Zhou You didn't know if he had become an omniscient and omnipotent god in his dream, but he could see with his eyes and record every change that occurred at the genetic level.

His mind was not bombarded by this massive amount of information, he just instinctively acted as an observer and recorder.

Immediately afterwards, the history of life on earth entered the Ordovician period.

The Ordovician biological radiation occurred.

Many biological phyla and classes born in the Cambrian began to take different paths due to different environments and different needs, forming different families.

Then, there was the first mass extinction of species that cut off the Ordovician and Silurian periods with a single blow.

During the mass extinction, about 60 percent of the species on Earth were buried in the dust of history.

Human scientists in the past had three main conjectures about the causes of the first mass extinction.

One theory is that it is cyclical changes in climate, another is that an asteroid hit the earth, and the third theory is that the gamma rays released when a supernova exploded happened to cover the solar system and the earth, seriously damaging the earth's ozone layer.

, and at the same time completely destroyed the atmospheric environment on Mars, extinguishing the possibility of life on Mars.

Previous anthropologists have debated endlessly around these three hypotheses.

Zhou You himself is not a fan of any of these theories.

His own knowledge is not biased. He believes in all three major theories, but also believes in none.

But now, in his own dream, Zhou You completely abandoned the other two hypotheses.

He "with his own eyes" saw the earth's sky suddenly light up, and then "with his own eyes" he "watched" with his own eyes the gamma particle stream rushing down from the sky and scattering on the earth and oceans.

He also watched "with his own eyes" as the undersea ecology, which was as prosperous as an ancient city, rapidly withered.

However, life on earth was not completely destroyed. After all, 40% of life successfully withstood the disaster and entered the Silurian Period with the mission of reproduction or the instinct of biochemical reactions.

In the Silurian Period, ferns in the sea began to step onto the ground and became terrestrial plants.

Vertebrates with greater athletic ability became the new overlords of the sea.

Fish dominate the oceans.

It seems that if nothing unexpected happens, fish will slowly evolve higher intelligence and become a true civilization.

Time slowly moved from the Silurian Period to the Devonian Period.

But just like the first mass extinction, accidents happened again.

At the end of the Devonian period, several huge celestial bodies fell from the sky and hit the earth hard.

The earth shook, the crust was pierced, and magma erupted.

Toxic gases rose from holes in the earth's crust, covering the earth with gray smoke.

Smoke and dust have covered the sky for millions of years. This has made it difficult for photosynthetic plants in the ocean to survive and have died out.

The accumulation of various factors has made the ocean extremely hypoxic.

A large number of creatures living in the sea began to become extinct one after another, especially fish.

The Devonian Period ended.

More than 75% of life on earth also stops here.

But disasters and opportunities will always coexist.

Although the disaster at the end of the Devonian period was tragic, it left a rich legacy for the next generation.

There is insufficient oxygen in the ocean, but the oxygen in the air has reached a very high concentration after hundreds of millions of years of efforts by photosynthetic plants.

The massive volcanic ash released by the violent volcanic eruptions caused by the impact of celestial bodies, as well as the disintegrated celestial bodies themselves, brought rich nitrogen and phosphorus elements to the earth.

These are the sources of life.

In the tragic ruins, amphibians trapped in diving evolved lungs through painful iterations, allowing them to breathe air directly. Animals on the earth officially set foot on the earth.

The Carboniferous Period begins.

Arthropods and reptiles began to take the stage and became dominant.
Chapter completed!