After returning to their residence, Hua Feng and Yun Meng continued to understand and study more deeply, and slowly discovered that the history of the earth was far more complex than they imagined, and before anyone appeared, the species on the earth had already appeared with an incredible miracle of life, and ruled the earth for tens of millions of years.

Some experts have suggested that as the earth gradually cools from the very hot to the cool, simple organic compounds (single molecules) gradually form, and after mixing, they form more complex mixtures (polymers).

Later, ocean currents collect these large particles to "hot spots" such as coasts and deep-sea hot springs, where they may eventually form the first protocells. There is also evidence that the first cellular replication used ribonucleic acid (RNA) rather than deoxyribonucleic acid (DNA), and that DNA replication took a very long evolutionary period to emerge.

There are also theories that living things appear on alien planets.

Cambrian Explosion of Life:

In 1909, Charles Walcott, an American paleontologist and secretary of the Smithsonian Institution, was born in the name of Cha

les Walcott discovered the Burgess Shale at the Burgess Pass in British Columbia, Canada, and the rock blocks contain the oldest known illustrations of many important fauna groups in the history of the chemical record.

Walcott's findings were made for the so-called Cambrian explosion of life (Camb

ia

Explosio

) provides further evidence. The Cambrian explosion of life has been described as one of the major paleontological and geological problems, and in the fossil record of the Cambrian period (about 542 million to 490 million years ago), a variety of structurally complex animals suddenly appeared on Earth. While a complex animal of this magnitude had never been recorded in the Burgess Shale before, paleontologists were no strangers to the presence of trilobites and other animals of the Cambrian period, which baffled Charles Darwin.

The challenge posed to scientists by the Cambrian explosion of life was that no animal fossils had been found in older rock formations below the Cambrian Rock Formations in Darwin's time and for many years afterward. This is an extremely disturbing fact for Darwin's theory of evolution, because in the fossil record, structurally simple animal forms should precede structurally complex animal forms.

In On the Origin of Species, Darwin made this claim: "During these periods of such great span and little known, the earth was full of living life. "I can't give a satisfactory answer to the question of why we haven't found a fossil record of these primitive periods." ”

Invertebrate dominance period (5.1-438 million years ago):

The Ordovician period began 500 million years ago. Algae did not change much, and trilobite numbers still topped the list. At this time, the number and species of other invertebrates surpassed those of the Cambrian. The most common are corals, brachiopods, gastropods, sea lilies, and nautilus, among others.

The Earth's land during the Ordovician period did not change much due to the constant photosynthesis of aquatic plants. The oxygen content in the air increases further. Roughly less oxygen than the top of Mount Everest, the vast sea area is home to a large number of invertebrates of various phyla, and in addition to those already produced in the Cambrian, certain groups have been further developed, such as pencils, corals, brachiopods, sea lilies, bryozoans and mollusks.

Silurian and Devonian (439-363 million years ago):

After a long evolutionary period, the Earth has finally entered a period dominated by vertebrates. Fish became the hegemon of the time.

367 million years ago, a huge meteor pierced the night sky and crashed into the sea, and the sky was filled with electric light. This is when the global climate dries out and the temperature drops. Ocean currents eddy in new forms, cooling the oceans even further, making surface waters more salinity and dropping oxygen levels to very low levels. The impact of the meteorite may also cause more climate change. At least three or as many as six large objects from space may have crashed into the ocean during this period, resulting in the extinction of many marine life, including reef-building animals, many species of fish and brachiopods.

In the late Devonian, as the earth's climate became harsh, lakes and marshes dried up, shield fish species became extinct, and many species of fish were also threatened. During this long period of time, some of the branches of the total finfish adapted well to the environment, relying on their even-finned, inner nostrils and swim bladders to climb up to land in search of water and food, and over time, some of them evolved into primitive amphibians.

Due to the increase in oxygen in the atmosphere, an ozone layer was formed in the stratosphere that can absorb most of the ultraviolet rays, so that in addition to the protection of living organisms by seawater, an additional layer of protection was added to the earth's surface, thus creating conditions for the landing of Paleozoic plants. The earliest insects have become extinct, but insects are by far the most successful animals that have inhabited the planet.

They are the earliest terrestrial animals. Tropical rainforests are the most biologically abundant places, with insects making up one-third of the total weight of animals and plants.

The sturdy exoskeleton protects the critter from injury and prevents it from being dried out in times of drought and rain. Insects can lay hundreds, sometimes thousands, of eggs at a time. Even in the most dangerous or harsh environments, eggs hatch and grow, producing more insects.

It took 40 million years for plants and insects to create the conditions for amphibians to climb ashore from the water, where plants and herbivores provide ample food. Because there were no larger animals to compete with, amphibians spread rapidly. In the late Devonian period, 350 million years ago, a branch of the total-finned fish evolved into a primitive amphibian. Among them, the main trunk is the maze tooth, followed by the shell vertebrate and the slippery body.

Carboniferous and Permian (c. 363-251 million years ago):

During the Carboniferous period, the climate was humid, which led to the emergence of new and peculiar forests, the earliest forests on land. These forests were not as dense and dark as today's swamp forests, and they consisted of horsetails, thick layers of ferns, and tall, thin trees. New strange animals have settled in this peculiar landscape.

Amphibians of all shapes and sizes thrive in moist environments, as do huge insects.

Insects were the first animals to master the art of flying. Reptiles, birds, mammals, and even fish all take to the skies after them. Flying is greatly beneficial for evading predators, conquering new territories, and finding new food sources. At first, insects may run, jump, or slide down trees, but insects that are more athletic often survive until they develop wings.

Between 250 million and 65 million years ago, the history of biology was called the Mesozoic Era, which included the Triassic, Jurassic and Cretaceous periods of geological history.

The biggest feature of the Mesozoic biological world is that it continues to adapt to terrestrial life, gymnosperms have evolved pollen tubes, can carry out internal fertilization, completely get rid of dependence on water, and can adapt to terrestrial life more often, forming dense forests. Reptiles in the animal kingdom have also developed rapidly, evolving a wide variety of dinosaurs and becoming the overlords of the animal kingdom, occupying the three major ecological fields of sea, land and air.

Evolution of reptiles (about 2.5-205 million years ago):

Reptiles include large carnivores, light predators, scaly, pig-like beaks and crocodile-like fishivores that lived alongside the earliest dinosaurs. Many reptiles were larger and more common than the earliest dinosaurs, but both these reptiles and dinosaurs were much larger than the earliest mammals, and none of the mammals that emerged during this period were larger than mice.

From the vertebrate aspect, although the Triassic partially inherited the biological components of the Paleozoic, the emergence of new types of organisms is more important. Among vertebrates, in addition to the emergence of new turtles and turtles, more important is the emergence of alveolar reptiles, from which evolved crocodiles, dinosaurs, and later pterosaurs, birds, etc., creating a new biological situation for the earth.

Wu's crocodile and Turpan crocodile are representatives of early alveolars. However, the most evolutionary event of the Triassic is the emergence of mammals, which evolved from a basal reptile. Although it was still weak at the time, its progressive tectonic features predicted its strong vitality for world domination. The Kensley mammals are a side branch of the reptile to the mammal.

The appearance of plants in the early and middle Triassic is mostly drought-tolerant. The horsetail and sheep's tooth that grew in the swamps in the Late Triassic were quite luxuriant, and the gentle slopes of the low hills were covered with evergreen trees similar to those of modern times, such as pine, cypress, cycad, etc. The main flora that flourished in the Paleozoic was almost completely wiped out, most of the seed ferns disappeared, and the Kodak tree tended to decline.

From about 300 million years ago until the Triassic period, more than 70 million years later, shortly before the rise of dinosaurs, animals like Heterodontosaurus were the rulers of the land.

Reptiles in the sea: 235 million years ago, reptiles entered the water in the middle of the Triassic period. Their bodies grew to the size of whales and dominated the oceans for the next 170 million years until the end of the age of dinosaurs. The earliest large marine reptiles were Phantom Dragons.

Their teeth are long and pointed, making them ideal for catching fish, and their webbed toes help with paddling. The Shieldodontosaurs lived during the same period. These marine reptiles are 1.8 meters long and have carapaces on their sides. The dendrosaurus crushed and fed on seafloor shellfish with its large, flat teeth. Its teeth grow at the edge of the jaw and at the top of the mouth.

By 200 million years ago, plesiosaurs appeared. These marine reptiles have short tails, broad paddle-like forelimbs, and most have long necks.

The short-necked upper dragon was the largest of all plesiosaurs, with a body length of 12 meters, which is larger than a large transport truck. Ichthyosaurs also appeared during this period, and it grew larger, with a body length of 15 meters. They mysteriously disappeared 90 million years ago. The similarly sized moosaurus was a ferocious marine reptile that fed on fish, and they survived until the end of the dinosaur era, 65 million years ago.