Our planet is more than 4.5 billion years old. At the moment it appeared, it looked completely different. What happened in ancient times on the territory of modern Russia, and how it changed over the years - in the book “Ancient Monsters of Russia”.
3000 million years ago
In the first millions of years of its life, the Earth was like hell. There was constant acid rain here, and hundreds of volcanoes erupted. There were many more asteroids. Endless meteorite showers formed the planet - they crashed and became part of it. Some meteorites reached the size of modern cities.
One day, the Earth collided with another planet, one part of which joined us, and the second flew into orbit and over the years turned into the modern Moon.
Illustration from the book
3 billion years ago, a day lasted only 5 hours, and there were 1500 days in a year. A lunar eclipse occurred once every 50 hours, and a solar eclipse occurred once every 100 hours. It probably looked very beautiful, but there was no one yet to admire natural phenomena.
The science
Today, our neighbor Mars is a cold, red-desert planet. Liquid water no longer exists on its surface due to low atmospheric pressure and temperature. However, there is evidence that streams once flowed along its surface brackish liquid with a low freezing point.
Water on Mars under modern conditions can be ice, or it can turn into steam, bypassing the liquid state.
Ancient Mars
It turns out that approximately 4 billion years ago When Mars was a young planet, its atmosphere was denser and its surface was warm enough to support liquid water, which is very an important condition for the existence of life.
On the surface of Mars, as on the surface of the Earth, there are characteristic branched channels, which were formed by fluid flows. In the interior of some impact craters there are pools in which lakes once splashed.
Small craters disappeared over time, while larger ones retained signs of erosion. The water destroyed the rocks around 3.7 billion years ago. Layers of sediment are visible on the walls of the craters. There are also minerals that could have formed exclusively in the presence of water.
The animation presented in the following video shows what the Red Planet might have been like in those distant times when on its surface liquid water existed. Fast moving clouds symbolize the passage of time. A gradual transition from a warm and humid to a cold and dry climate is shown. The lakes dry up and freeze, and the sky changes color from soft blue to dirty pink:
It is not yet clear exactly is it long enough whether a favorable climate remained on Mars and whether life had time to arise on it during this time.
The earliest signs of earthly life presented as an organic chemical structure found in rocks on the island of Greenland. These rocks were once on the seabed. Approximate age of the structure – 3.8 billion years, that is, after the formation of our planet, only 700 million years. No fossilized remains of life that date back to this period have yet been discovered.
Fossils of actually existing microorganisms, according to some estimates, 3.5 billion years. By that time, conditions favorable to the emergence of life had already disappeared on Mars.
Comparisons between the histories of the two planets should be made with caution, the researchers warn, as chemical composition The surfaces of Earth and Mars are different, as is their volcanic activity.
How did life begin on Earth?
The earth appeared approximately 4.5 -5 billion years ago from cosmic dust and at first it was a hot ball.
The ancestor of all creatures living on our planet was called Last universal common ancestor. He lived approximately 3.5-3.8 billion years ago. This ancestor cannot be considered the first living creature of our planet.
There are several hypotheses for the origin of life on our planet, including the spontaneous generation hypothesis and the bringing life from space, including from other planets, for example, from Mars.
According to one of the most popular versions, life on Earth appeared after it was enough liquid water and special climatic conditions developed.
The first living creatures were prokaryotes, single-celled creatures without a formed nucleus. These creatures looked like modern bacteria. Living organisms have evolved and become more complex over the course of many millions of years.
- 1000-600 million years ago there were already jellyfish, mollusks, echinoderms, polyps and flatworms on Earth.
Having appeared in the ancient ocean, some animals gradually began to move onto land, while others remained floating in the water. This happened 416-360 million years ago V Devonian period.
MOSCOW, September 27 - RIA Novosti. Japanese geologists have found organic rock deposits in northeastern Canada that indicate life must have already existed on Earth at least four billion years ago, according to a paper published in the journal Nature.
The first living organisms appeared on Earth during the Archean era, and there is still no generally accepted point of view about how and when life began. There is now some fossil evidence that microbes already existed in Earth's primordial oceans some 3.4 billion years ago, but many scientists believe life may have begun much earlier than that.
Graphite from Greenland showed scientists the presence of life 3.7 billion years agoScientists have identified facts that suggest that graphite in the depths of Greenland arose as a result of the activity of bacteria. This “pushes back” the time of the origin of life by 300 thousand years.Three years ago, Japanese geologists found hints that life already existed on Earth about 3.7 billion years ago by studying graphite samples from Greenland. Last year, scientists found the first clear evidence of life in that era, and in 2015 they found in Australia suspected traces of life that inhabited Earth's oceans 4 billion years ago. British geologists recently found hints of microbes that lived on Earth almost immediately after the birth of the planet, 4.28 billion years ago.
Akizumi Ishida from the University of Tokyo (Japan) and his colleagues, who discovered traces of life in Greenland, continued their excavations, trying to find other deposits of graphite, “molded” from the remains of the first living organisms on Earth.
Scientists searched for these deposits using an already proven method, studying the structure, chemical and isotopic composition of the most ancient rocks of the Earth, formed on the most ancient continental platforms. As a rule, graphite of biogenic origin is distinguished by two things - a low proportion of “heavy” carbon-13 and the special structure of its grains, which includes many elements similar in shape and size to the cells of bacteria and archaea.
Isis and his associates found similar deposits in the northeast of Canada, near the city of St. John's, the capital of the island of Newfoundland. Inside local rocks that formed approximately 3.95 billion years ago, scientists found many small voids containing graphite.
This discovery forced them to break up about one and a half hundred cobblestones from Newfoundland and study in detail the isotopic composition of these inclusions and analyze their shape. In total, Japanese geologists found approximately three dozen graphite deposits that met both criteria of their biological origin.
The large number of graphite samples allowed Ishida and his colleagues to reveal some details about what the life that gave birth to them looked like and in what conditions it lived. For example, fairly high proportions of yttrium and some other rare earth metals indicate that the first microbes of the Earth did not live in freshwater lakes, but in salty seawater. Today, many scientists doubt this idea, pointing to the absence in Earth's primordial ocean of many critical elements, such as boron or manganese, that were present in large quantities on land.
In addition, the low concentration of "heavy" carbon in these deposits indicates that these bacteria fed on hydrogen or pure organic matter, using their energy to convert carbon dioxide (CO2) molecules into carbon monoxide and use it to synthesize amino acids and other " bricks of life."
This, in turn, confirms one of the popular theories today about what “Luca” (LUCA), the common ancestor of all living things, who lived in the vicinity of underwater volcanoes or hydrothermal vents, looked like. Further excavations, Japanese researchers hope, will help add new details to his portrait.
Our planet is about 4.5 billion years old. One day something happened that changed our Earth once and for all - life arose on the planet! Every person, every animal, every insect or flower owes its origin to the organism that gave rise to all the modern diversity of life on Earth - the protocell! Do you want to see our evolutionary path from cell to Homo sapiens? That way!
4.54 billion years ago, the Earth formed from an accretion disk orbiting the Sun...
Much of the Earth was molten due to active volcanism and frequent collisions with other space objects. It is believed that one of these large impacts led to the tilt of the Earth's axis and the formation of the Moon.
Over time, such cosmic bombardment ceased, allowing the planet to cool and form a solid crust.
Source: charter97.org
Volcanic degassing created the primordial atmosphere, but it had almost no oxygen and would have been toxic and unlivable for humans in the modern world.
The water delivered to the planet by comets and asteroids condensed into clouds and oceans. Water is full of chemical and organic elements. The earth finally became hospitable to life, and its earliest forms enriched the atmosphere with oxygen.
Source: charter97.org
Chemical atoms are combined in a precise and necessary sequence, creating a layer of genetic materials. Reproduction of such organisms required resources: energy, space and tiny amounts of matter, which soon became scarce, leading to competition and natural selection that selected those molecules that were more efficient at reproduction. Then DNA became the main reproducing molecule.
The archaic genome soon developed internal membranes that provided a stable physical and chemical environment for more favorable development later, creating the first Protocell on our planet!
Source: sunely-tales.livejournal.com
Passing from one generation to the next, genes encourage cells to reproduce, thus ensuring survival. And for the next 2 billion years, these cells will be the only form of life on earth. But one day, a random action changed everything - two cells merged into one, combining their genes, and after that the cell cloned itself. This offspring had the genes of not one, but two cells - two parents. We called this accident sex. Sex provides variety. But not everything goes smoothly, and when cells multiply, their genes mix and divide internally. Cells mutate and the mutation becomes more complex. The difference in cells increases. And there are more and more such cells. Various types are formed. And the tree of life is divided into billions of species. But only one of which will lead to us...
Source: www.youtube.com
Mutation and diversity expand in the ocean, becoming larger and more complex and leading us to an 8-centimeter ancestor - and this is an aquatic worm. Yes, this is probably what we looked like 550 million years ago!
Source: www.youtube.com
Mutation creates a division of species into male and female. We create more offspring, pass on more genes. But finding a partner is almost impossible when everyone around you is completely blind. In a sea of absolute darkness, being able to see will give us a very important advantage. And nature's most amazing innovation begins to take shape. Several skin cells mutate. We can now distinguish light from dark, find more food, and better avoid predators. We began to live longer and produce more offspring. And very soon, creatures with light-sensitive cells dominate in number. Cells improve through mutation and countless generations. Natural selection begins to act, allowing all living beings to adapt in this world. And so our ancestors developed eyes.
Source: www.youtube.com
Now we need to draw conclusions from what we saw. And behind our eyes, a tiny number of nerve endings are grouped into one whole. They are no larger than the head of a pin. One day it will become one of the most complex and amazing organs given by nature - the brain!
Source: www.youtube.com
So, 521 million years ago, Milokunmingia appeared, a fish-like creature only 2.8 cm long, which can make simple decisions and process simple information.
Source: www.archo-cheirus.com
But we are no longer alone in this underwater world...
Source: student.societyforscience.org
Source: www.bbc.com
The formation of various species led to the existence of many other creatures, one of which is Anomalocaris. With a body length of up to 60 cm, this creature posed a real threat to us and in order to survive, it was necessary to mutate and adapt...
Source: ru.wikipedia.org
The jaws and teeth of Milokunmingia become stronger and stronger, and the body becomes covered with a shell. This is how the 30-centimeter armored fish Sarcopterygium appears.
Source: www.youtube.com
But staying in a world with too many predators becomes even more difficult. And the fish are saved from extinction in shallow waters, where predators can hardly reach them.
Source: www.nkj.ru
And here natural selection comes to our aid again. Thanks to millions of years of evolution and changes of thousands of generations, our bodies have adapted and we have done something that no fish has ever done - we inhaled air. The air penetrates into a new organ for us - the lungs. Now we are the amphibian Ichsthyostega. We can breathe both on land and under water, closing our throats and switching from lungs to gills and vice versa. Today we do not have gills, but the mechanism of their action still works in the form of spasms, which we call hiccups. Even 550 million years ago, thanks to atmospheric oxygen reserves, the ozone layer was formed. It blocks ultraviolet radiation, allowing organisms to escape to the ground. And then, 365 million years ago, Ichstyostega emerges from the water onto land. The ground is hot. Our skin is dried out by the sun's rays, and now finding food is very difficult for us.
Once again, natural selection helped adapt. Thick skin saved us from the scorching sun, and strong claws, which would one day become our nails, helped us move in difficult terrain. And we become Casineria, only 15 cm long.
Source: www.the-submarine.ru
We have already adapted to life on land, but the eggs we lay have not yet. They need a thicker shell so as not to dry out under the scorching sun. But the problem is that the male will not be able to fertilize eggs with a thick shell, but he is able to do this before the shell is formed - inside the female. Sex as we know it begins here. The result is a phenomenon - an embryo with all the necessary nutrients is sealed into an egg with a thick shell.
Source: evolution.powernet.ru
Sex has been the best way to increase genetic diversity and maintain our species. And about 320 million years ago, Casineria evolves into Anthracosaurus. With a body length of up to 2 meters and powerful teeth, almost nothing threatens it.
Source: animalsfoto.com
But the unexpected happened, and 250 million years ago, several thousand kilometers away, in distant Siberia, the earth split, and molten streams of lava rushed out from the bowels of the earth. Soon, hot lava covered an area equal to the area of the United States of America, and through cracks penetrated several hundred meters deep into the earth. This went on for almost half a million years. Trillions of tons of harmful carbon dioxide trap the sun's rays in the atmosphere. Temperatures soar to 100 degrees. All plants, herbivores and, finally, predators became extinct. Then 95% of all living organisms on our planet died. Very few managed to survive, among whom were us and the creatures that would soon turn into dinosaurs. When the fight for survival ended, the battle for supremacy began.
It's been 30 million years since eruptions killed 95% of life on earth. When the eruptions started, we were the size of a large monitor lizard. But now we are no bigger than cats, covered with fur, we are now Yuramaya. Over the course of several million years, we have become smaller, so that we are now harder to catch, and we are becoming nocturnal. Now we are even more difficult to notice, but we are cold and scared. The tiny muscles around the hair roots contract and thus prevent cold air from entering our body. That is why even today, when we are cold or scared, we get so-called goose bumps.
Dinosaurs are the most useful creatures we have ever encountered in the course of evolution. Thanks to them, we have very developed senses and brilliant brains. If it weren't for them, we would still be laying eggs. To protect their offspring from hungry dinosaurs, our ancestors now give birth to fully formed babies instead of leaving them to fend for themselves in eggs. And now we feed them milk. Sweat glands evolved into mammary glands. This is a very important period in our history of development from cell to human. The birth of a new class of creature, which in turn gave birth to more than four thousand species of different animals, from the smallest mouse to a huge whale, as well as you and me. This is the class mammals. Yuramaya coexisted with dinosaurs for almost 165 million years!
And no one knows how such a neighborhood could have ended if not for the well-known catastrophe. 65 million years ago, an asteroid (10 km in diameter) crashes into the earth in the Gulf of Mexico near the Yucatan Peninsula. The power of this explosion was 2 million times stronger than the most powerful thermonuclear Tsar Bomb!
And in order to escape the fire, smoke and ashes of fires, Yuramaya seeks refuge mainly underground, so that 64 million years ago evolution turned this animal into a 15-centimeter Purgatorius.
But new life begins to sprout from the ashes of destruction. 60 million years ago, fruits full of nutrients begin to ripen on the trees. The more fruits we eat, the longer we live. And we leave the earth for new life on the trees. For a new world we need a new body. We have come a long way from that very first cell and are finally beginning to acquire some resemblance to our species. And so, about 50 million years ago, we became the first in the class of mammalian primates - Anthropoids!
For more than 10 million years, extreme weather has changed the structure of the forest. The forests are getting smaller and food is now harder to find. And again natural selection intervenes. Our tail shrinks almost to the back, where it remains as a tailbone, and remains as a reminder of the days when we jumped between the trees. And now we no longer jump, we straighten up. Our arms become more flexible and longer. Temperature changes forever changed our ancestors, including us. 6 million years ago we are an ancient genus of hominids - Ardepithecus. We are 120 centimeters tall, weigh 40 kilograms and have a brain the size of an orange.
Our once dense tropical forest has thinned out. We can stand confidently on branches and hold on to them tightly, but in order to get more food, we need to let them go. And almost 4.5 million years ago - we take our first steps. Walking on our feet quickly leads us to food, which, without difficulty, we can now take with freed hands.
We are learning quickly. Ardipithecus is smart enough to learn and remember. Walking is passed on from parents to children. Over the next 1.5 million years, our bodies develop and we can walk faster and longer.
But in Ardepithecus, the structure of the pelvis remains very narrow, and the birth of a fully formed fetus becomes almost impossible. Now children need to be born earlier, when the baby's head is small enough and the body is not yet fully formed. That's why we are one of the few of our kind who raise, feed and protect our children from problems for many years to come. And then 3.2 million years ago - we become Australopithecus!
Our brains are about the size of a grapefruit, and we now walk on two legs all the time. Natural selection helps us increase brain performance, such as by weakening the jaw muscles. Now the skull and jaws are freed from the rigid connection, which leads to inevitable growth of the brain, and it doubles in volume!
2.3 million years ago we evolved into Homo Habilis or Homo habilis!
We walk on two legs, we have large and developed brains, and we are a completely new creation.
Now, in order to get more meat from a killed animal, we need something sharp and some incredible incident helped us make the first tool out of stone! This is the key to a completely new door in our lives. Thanks to him, we will learn to cultivate soil, build cities, and one day we will even fly into space! Our fingers have become stronger. Today we can hold a mug or write with a pen because 2 million years ago the use of tools changed us and the course of our evolution...
The family tree of our species is a complex puzzle with many pieces missing. But 1.8 million ago, the missing piece found its place in this puzzle and Homo Erectus - Homo erectus - appeared on the scene!
We have learned to work together with other members of society. Thanks to the discovery of a way to make fire, our lives have changed. Protected from the fear of darkness, our extended family unites. By working and foraging together, these early communities received food more often, and of course lived longer. This is the advantage of family life. And today, most of us call family the meaning of life.
Meat cooked over fire is much easier to chew. The powerful teeth at the base of our jaws that once helped us chew solid food now remain hidden there as wisdom teeth. In 35% of us they do not grow at all, as a sign that they have simply become unnecessary in the course of our evolution. By spending less energy on eating, our ancestors now had excess energy. Our brains grew to the size of a small volleyball and became 50% larger after the invention of cooking. And now our ancestors are looking for ways to communicate. Thanks to natural selection, our tongue changes its shape, goes deep into the mouth and, with the participation of hyaluronic acid, acquires the necessary shape, which helps our ancestors pronounce individual sounds... and finally words. We have acquired another tool - the ability to speak. Thus, after 3.5 billion years of evolution, Homo Sapiens - Homo sapiens - appeared 200 years ago!
Of course, there are many questions in the history of our evolution. The mere fact that we were able to find at least some evidence of evolution among millions of square kilometers is already good, but most of it is lost forever!
But there is one thing we should not doubt. The desire to survive turned us from one of the most primitive forms of life into Homo sapiens! Armed with tools, the ability to communicate and with superior intelligence, we conquered every continent. We developed and adapted to a new environment, new difficulties until we became the undisputed rulers of this World!
It’s incredible, but if we turned back time to the very beginning, our chances of surviving would be almost zero. Because if, in the course of evolution, even one small particle had changed, one successful mutation or one predator, we would not be here to piece together the pieces of this incredible 3.5 billion year history of humanity!
For a more detailed and fascinating version of human evolution, see here!
Illustrations by Simone Marchi for a research paper in the journal Nature.
NASA scientists have reconstructed the events that took place at the very beginning of the existence of our planet. The Earth, during its formation period from 4.5 to 3.5 billion years ago, was a hot ball, subject to continuous bombardment by extraterrestrial bodies. Its oceans evaporated, turning into steam, cracks appeared in the still young crust, and the surface was filled with lava.
Very little has survived that could be used to reconstruct a picture of what was happening. There are virtually no rocks older than 3.8 billion years left. The only evidence from the distant past is some zircons less than one millimeter in size contained in volcanic rocks. Radioactive decay data estimates their age to be 4.4 billion years.
Studying the distribution of zircons on Earth provided the researchers with a way to calibrate computer simulations.
Also, in order to learn more about the period immediately after the formation of the Earth, scientists used geological data from the Moon and other objects in the solar system.
The computer model showed that the Earth, in addition to surviving collisions with many small and medium-sized asteroids, most likely also collided with several really large objects that melted the entire surface of the planet. This theory suggests that the Earth's surface melted several times, but significant periods of time may have passed between these collisions. And if life arose on Earth, it had to be able to withstand high temperatures and hide deep under the surface.
After a billion years of bombardment, lava eruptions and ocean evaporation, the first hypothetical supercontinent of Vaalbara formed, which subsequently broke apart. This happened approximately 2500 million years ago. The name Vaalbara comes from the names of the procontinents Kaapvaal in South Africa and Pilbara in Western Australia. The migration routes of the Kaapvaal and Pilbara procontinents further indicate that they were once connected. This is confirmed by geochronological and paleomagnetic studies, which show that the procontinents experienced a circular transverse separation at an angle of 30°, after which they no longer touched.
