A brief history of the earth
Why is the earth only 4.6 billion years old?
The celestial bodies in the solar system formed almost at the same time, including meteorites derived from various asteroids, so the formation of the earth and meteorites The time is the same, that is, the same age.
The vast majority of meteorites that fall on the earth originate from asteroids in the solar system. Through age determination of meteorites on the earth, we can know the Real age.
In 1956, Claire Patterson measured the age of the earth through a meteorite:45.5±70 million years.
This is also the most accurate number so far, no one can match.
So what happened to the earth in 4.6 billion years?
< p style=”text-align:center”>Precambrian
(45~542 million years ago)
About 4.55 billion years ago (Precambrian)
With the formation of the solar system, the original earth was born.
The earth has no oxygen, no land, only a sea of magma.
At the same time, the planets continue to collide with the remaining matter after the formation of the solar system.
About 4.53 billion years ago (Precambrian)
The quality of the earth is increasing, attracting”Theia“.
This is a planet with the same size and mass as Mars.
It keeps moving closer to the earth. After a big collision,
“Theia”Part of the mass melted into the earth, and the remaining material and ejecta formed the moon.
About 4.45 billion years ago ( Precambrian)
The oldest mineral, zircon, was discovered in Australia, about 4.4 billion years ago.
The discovery of ancient zircons indicates that the earth is slowly condensing at this moment, and the crust is beginning to form.
About 4 billion years ago (Precambrian)
The oldest rock, Acasta gneiss, was discovered in Canada, about 4 billion years ago. The ancient gneiss announced the birth of the first continent on earth.
About 40-3.8 billion years ago (Qianhan Wu Ji)
The earth, moon, and other planets were bombarded by meteorites and comets.
During this period, the earth formed the initial ocean, but there were no plants, no people, no life, only silence.
About 3.8 billion years ago (Precambrian)
The earliest life appeared.
The origin of life is still a mystery. The earth first gave birth to molecules that can replicate itself.
Subsequently, bacteria and archaea were differentiated. The earliest known and highly reliable biological fossils were formed 3.5 billion years ago and came from stromatolites in Western Australia.
About 2.45 billion years ago (Precambrian)
The cyanobacteria slowly produced oxygen, accumulating less into more , The earth entered the first major oxidation event.
But oxygen is toxic-for anaerobic organisms, this is a disaster, and a lot of lives die.
About 2.4 billion years ago (Precambrian)
During the major oxidation event, a large number of anaerobic bacteria died and the methane released decreased; photosynthetic organisms flourished and consumed a lot of carbon dioxide; and Various geological movements have led to a decrease in carbon content on the surface.
The Earth has entered the most severe and longest-lasting Great Ice Age-the Huron Ice Age.
about 1.3-9 billion Years ago (Precambrian)
Orogeny, land masses merged to form a supercontinent-Rodinia
About 850 million years ago (Precambrian)
Do you remember the great oxidation event? 1.6 billion years have passed since this moment, and the ocean and land have reached a saturated state of oxygen (rocks, iron and various minerals are completely oxidized).
So oxygen began to accumulate, and oxygen content soared-ushering in the second major oxidation event. For the differentiation of eukaryotes, a key link is buckled, and a life explosion is about to come.
About 750-630 million years ago (Precambrian)
Don’t worry, wait for the explosion of life First class.
With the split of Rodinia, the earth entered the second ice age-Cryogenian.
This is the second most serious ice age. During the period, the polar ice cap covered the equator, and the ocean was completely frozen, forming a”snowball earth.”
White snow, an icy, dry atmosphere, only the scorching sun on the head, but can’t keep a trace of warmth, no matter how much sunshine it will be reflected.
About 635 million years ago (Precambrian)
Broken by ice for hundreds of millions of years, it was broken by volcanic activity.
The earth that stopped photosynthesis, carbon dioxide accumulates rapidly, and the greenhouse effect dispels the”snowball earth.” The ice and snow melt, the earth warms up, and oxygen levels continue to soar.
The prelude to the great explosion of life sounded, and multicellular organisms came into being-the Ediacaran biota.
They have no digestive organs, they are leaf-shaped, tubular, and algae-shaped. They are generally immobile. They are attached to the bottom of the sea. They use liquid to support their flat bodies and obtain nutrients from flowing seawater.
100 million years later, the Ediacaran biota suddenly disappeared, marking the entry of the earth New era.
(5.42~251 million years ago)
About 542 million years ago (Cambrian)
The explosion of life played the main song, and biodiversity showed an explosive development.
Animals put on armor one after another, a large number of hard animals evolved, and the arms race began.
The trilobites that adults and children have heard of appeared. At this time, the marine overlord was Odd shrimp, They can grow up to 1 meter long and can be seen in oceans all over the world.
But whether it is a strange shrimp or a trilobite, they are all marine invertebrates.
Haikou fish and Kunming fish are known to have evolved the primitive vertebrae, eyes and brain and other important head sensory organs.
About 480 to 440 million years ago (Ordovician)
Shallow sea Widely distributed and suitable for the climate, marine invertebrates are more prosperous, and the differentiation is more significant.
Inhabited by trilobites, brachiopods, hornstones, crinoids, and horseshoe crabs.
Compared to the ocean, terrestrial ecosystems are indeed desolate.
Thanks to the oxygen generated by photosynthesis, the ozone layer is formed after accumulation, which absorbs most of the sun’s ultraviolet rays. Plants and fungi have grown on the edge of the water for a long time, maybe it’s time to cross the waterline.
Some plants landed first, forming ecosystems such as wetlands, lagoons, and deltas. The increasingly complex food web also created opportunities for our “ancestors”.”.
About 370 million years ago (Devonian)
A group of lung-like structures tried to land. They put their fins As a leg, he slowly left the water, climbed onto the land, raised his neck, and looked around. The first four-legged animal appeared.
Since then, countless fish-like”monsters” twisted their bodies and waved their fins to become active in various ponds and swamps.
All four-legged animals have their origins Since then, including dinosaurs, pterosaurs, mosasaurs, and you and me.
About 3.59~299 million years ago (Carbon Ji)
The plants that landed first are now up to 40 meters high, and as far as the eye can see, they are all ferns.
The trouble has arisen. The decomposers cannot decompose the lignin of plants. The carbon element accumulates in the lignin of plant debris. These plant debris is today’s abundant fossil energy.
The carbon element is buried deep underground, the carbon dioxide content drops sharply, the oxygen content rises, and the oxygen content of the earth’s atmosphere may reach as high as 35%. (Do you remember the second major oxidation event? The highest peak in the picture is the Carboniferous, forget it? Turn it up)
The oxygen content has soared, and the biggest beneficiaries are not quadrupeds, but insects. .
Because insects have a simple breathing method and rely on stomata to diffuse oxygen throughout the body, higher oxygen content can push insects to break through their limits.
And arthropods that landed nearly 100 million years earlier than quadrupeds.
About 2.99~251 million years ago (Permian)
The dominant position of the forest has changed, and gymnosperms have begun to replace ferns.
Insects began to diversify, tetrapods prospered in large numbers, and the star creature trilobites tended to become extinct.
The early ancestors of mammals, theraptors, have gradually become the dominant animals on land.
About 251 million years ago (*Permian—— Triassic extinction event)
Emeishan dark rock and Siberian dark rock volcanoes erupted one after another.
The lack of oxygen leads to the death of the ocean, and up to 96%of sea creatures disappear; animals and plants are poisoned by hydrogen sulfide and the ozone layer is destroyed. About 70%of terrestrial vertebrates disappeared, even insects were hit hard, and about 83%of the genera disappeared.
The mammalian ancestors briefly ruled the land.
The celebrity trilobite we are familiar with has also come to a close.
A catastrophe ended the Paleozoic era, and the evolution of life entered a new stage.
(251~66 million years ago)
About 240 million years ago (Triassic)
The continents collided with each other, and the disintegrated continents came together again-Pangu continent. Since the interior of the continent is far from the ocean, it is mostly desert areas, dryness and lack of water, and global hypoxia caused by extinction events.
It seems that only to get rid of the restrictions brought by thin air , Have the opportunity to occupy the land after the mass extinction baptism.
The main dragons did it. They used their limbs to prop up their bodies, their lungs left the ground, and they could keep breathing during exercise, which meant they had more vitality and quickly became an advantage on land. vertebrate.
About 231~200 million years ago (Triassic)
The main dragons continued to adapt to radiation, and one branch evolved into a dinosaur.
However, the land ruler at this time is crocodile-another evolutionary branch of the main dragon.
The ruler of the sky is pterosaurs-another evolution branch of the main dragons.
So far, the main dragon formally takes over the land and sky of the earth.
Faced with the sudden emergence of land and air, a group of terrestrial reptiles have already found another way out and returned to the sea.
From the results, it is wise. The marine ecology has been severely hit by the mass extinction, causing a large number of blank niches, and they quickly become the new rulers after returning to the ocean. Ichthyosaur.
About 200 million years ago (*Triassic-Jurassic extinction event)
Mid-Atlantic The Magma Province erupted, killing at least 50%of the species.
The pterosaurs, the ruler of the sky, are spared, and the dominance of the family is unshakable.
Ichthyosaurs, the ruler of the ocean, were spared, and were equally divided with the late plesiosaurs.
Large crocodile, the land ruler, was collectively killed in action, and the land is handed over. Who will take over? The long-established dinosaurs quickly filled the vacant ecological niche and fully occupied the terrestrial environment.
The age of dinosaurs is officially here.
About 180 million years ago (Jurassic)
Pangea began to split, with Laurasia in the north and Gondwana in the south.
Independent plates increased and coastlines increased, forming a warm and humid Jurassic world.
The dinosaurs began to spread to all continents, and geographical isolation led to an increase in biodiversity.
In the ocean, ichthyosaurs and plesiosaurs occupy each other’s living space.
In the sky, pterosaurs stand out, and their dominance is still stable.
Under the ground, tiny mammals are living, waiting for their chance.
About 120 million years ago (Cretaceous)
Since the Jurassic, dinosaurs have made various attempts and evolutions in flight. For example, two pairs of wings, bat-like wing membranes, etc., but most of them have walked into the dead end of evolution, fixed in the Cretaceous period.
Only one branch of dinosaurs successfully evolved into birds, and the pterosaur’s sky supremacy began to shake.
At the same time , Angiosperms have adapted to radiation, and their numbers have surged.
About 66 million years ago (*Cretaceous-Paleogene mass extinction)
One diameter The 10-km-long meteorite hit the Yucatan Peninsula, causing global fire storms, volcanic eruptions, earthquakes, tsunamis, and subsequent global cold winters, and the age of dinosaurs ended.
The food web collapsed, and the creatures at the top of the food web were severely affected. A series of star animals such as dinosaurs, pterosaurs, mosasaurs, and plesiosaurs, etc. have been closed. Only small animals hiding in oceans, rivers, caves, swamps and tree holes can get a chance.
The descendants of mammals and dinosaurs that have survived the entire Mesozoic era have left fire. If one survives, there will be future fortunes. Radiation evolves and joins hands to become the dominant animal of the new generation.
< p>Uninvited guests outside the sky ended the Mesozoic era, and the earth entered a new era.
(66 million years ago ~ today)
about 65 million Years ago
Laurasia in the north and Gondwana in the south have completely disintegrated, and the seven continents are beginning to take shape.
About 2.58 million years ago
The Quaternary Great Ice Age began, and the Antarctic continent and Greenland formed a permanent ice sheet, Eurasia Large continental ice sheets have also appeared in the north and the north of North America, and mountain glaciers have been widely seen in high latitudes or high altitudes throughout the world, which continues to this day.
Then the earth was in ice age Cycles that alternate with the interglacial period.
About 2~11,000 years ago< /p>
The first animal in the Hominid appeared 2 million years ago.
Homo erectus mastered the ability to control fire at the latest 790,000 years ago.
Subsequently, human beings walked out of Africa one after another, and later ones eliminated the former and continued to move forward.
About 11,000 years ago, some”Homo sapiens” arrived at the southern tip of South America and have spread all over the world. .
About 11,000 years ago-present
The last glacial period ended, the earth entered an interglacial period, and human civilization emerged.
If the history of the earth is converted into 24 hours,”Homo sapiens” will appear in the last 2 seconds, enter the Bronze Age in 0.1 seconds, and the Renaissance in 0.012 seconds…
p style=”text-align:center”>So, how many seconds do you live?