Each of us sometimes cares about questions that are difficult to find answers. These include an understanding of the meaning of their existence, the structure of the world, and much more. We believe that everyone once thought about the development of life on Earth. The eras that we know are very different from each other. In this article, we will examine in detail how life on Earth was born and how exactly its evolution took place.
Catharheus
Katarhei is an era when the earth was lifeless. Everywhere there were volcanic eruptions, ultraviolet radiation and no oxygen. The evolution of life on Earth began its reckoning precisely from this period. Due to the interaction of chemicals that have enveloped the earth, properties characteristic of life on Earth begin to form. However, there is another opinion. Some historians believe that the Earth was never empty. In their opinion, the planet exists as much time as life on it.
The era of the catarchea lasted from 5 to 3 billion years ago. Studies have shown that during this period the planet did not have a core and crust. An interesting fact is that at that time the day lasted only 6 hours.
Archaea
The next era after the catarchea is Archean (3.5-2.6 billion years BC). It is divided into four periods:
- neoarchaeus;
- Mesoarchaeus;
- paleoarchean;
- eoarchaeus.
It was during the Archean that the first simple microorganisms were born. Few people know, but the deposits of sulfur and iron that we mine today appeared precisely in this period. Archaeologists have found the remains of filamentous algae, whose age allows us to attribute them to the period of the Archean. At this time, the evolution of life on Earth continued. Heterotrophic organisms appear. Soil is formed.
Proterozoic
Proterozoic is one of the longest periods of the Earth's development. It is divided into the following stages:
- Paleoproterozoic era;
- mesoproterozoic;
- neoproterozoic.
This period is characterized by the appearance of the ozone layer. Also at this time, as historians say, the volume of the world's oceans was fully formed. The Paleoproterozoic era included the sidereal period. It was in it that the formation of anaerobic algae occurred.
Scientists note that it was in the Proterozoic that global glaciation occurred. It lasted for 300 million years. A similar situation is characterized by the ice age, which was much later. During the Proterozoic, multicellular organisms appeared . Among them are sponges and mushrooms. It was during this period that ore and gold deposits formed. The Neoproterozoic era is characterized by the formation of new continents. Scientists note that all the flora and fauna that existed during this period is not the ancestor of modern animals and plants.
Paleozoic
Scientists study the geological era of the Earth and the development of the organic world for a long time. In their opinion, the Paleozoic is one of the most significant period for our modern life. It lasted about 200 million years and is divided into 6 time periods. It was in this era of Earth's development that terrestrial plants began to form. It is worth noting that during the Paleozoic period animals came to land.
The Paleozoic era was explored by many famous scientists. Among them are A. Sedgwick and E. D. Phillips. It was they who divided the era into specific periods.
Paleozoic climate
Many scientists conducted research to find out the stages of development of life on Earth. Eras, as we said earlier, could last long enough. It is for this reason that over the course of one reckoning in a certain area of the Earth at different times there can be an absolutely opposite climate. So it was in the Paleozoic. At the beginning of the era, the climate was milder and warmer. There was no zoning as such. The percentage of oxygen is constantly increasing. Water temperature ranged from 20 degrees Celsius. Over time, zoning began to appear. The climate has become hotter and wetter.
By the end of the Paleozoic, as a result of the formation of vegetation, active photosynthesis began. There was a more pronounced zoning. Climatic zones formed. This stage has become one of the most important for the development of life on Earth. The Paleozoic era gave impetus to enrich the planet with flora and fauna.
Flora and fauna of the Paleozoic era
At the beginning of the Paleozian period, life was concentrated in water bodies. In the middle of the era, when the amount of oxygen reached a high level, land development began. Its very first inhabitants were plants, which first performed their activities in shallow water, and then moved to the shore. The first representatives of the flora who mastered the land are psilophytes. It is worth noting that they had no roots. The Paleozoic era also includes the formation of gymnosperms. Tree-like plants also appeared. In connection with the appearance of flora on the earth, animals gradually began to appear. Scientists suggest that the first herbivorous forms appeared. For quite a long time, the process of the development of life on Earth lasted. Eras and living organisms have constantly evolved. The first representatives of the fauna are invertebrates and spiders. Over time, insects with wings, mites, mollusks, dinosaurs, reptiles appeared. In the late Paleozoic period, significant climatic changes occurred. This led to the extinction of certain animal species. According to preliminary estimates, about 96% of the inhabitants of water and 70% of land died.
Paleozoic minerals
It is with the Paleozoic period that the formation of many minerals is associated. Rock salt deposits began to form. It is also worth emphasizing that some oil basins originate precisely from the Paleozoic era. Coal strata began to form, which account for 30% of the total. It is also with the Paleozoic period that mercury formation is associated.
Mesozoic
The next after the Paleozoic, was the Mesozoic. It lasted about 186 million years. The geological history of the Earth dates back much earlier. However, it was the Mesozoic that became the era of activity, both climatic and evolutionary. Formed the main borders of the continents. Mountain building has begun. There was a division of Eurasia and America. It is believed that it was during the Mesozoic that the climate was the warmest. However, at the end of the era began the ice age, which significantly changed the flora and fauna of the earth. Natural selection has occurred.
Flora and fauna in the Mesozoic era
The Mesozoic era is characterized by the extinction of ferns. Gymnosperms and conifers predominate. Angiosperms are formed. It is in the Mesozoic period that the fauna flourishes. Reptiles become the most developed. In this period, a large number of their subspecies existed. Flying reptiles appear. Their growth continues. By the end of the Mesozoic era, some representatives weigh about 50 kilograms.
In the Mesozoic, the development of flowering plants gradually begins. By the end of the period, a cold snap begins. The number of subspecies of near-water plants is reduced. Gradually extinct predatory dinosaurs and invertebrates. It is for this reason that birds and mammals appear.
According to scientists, birds originated from dinosaurs. They associate the emergence of mammals with one of the subclasses of reptiles.
Cenozoic
Cenozoic is precisely the era in which we live today. It began about 66 million years ago. At the beginning of the era, continents were still dividing. Each of them was dominated by its own flora, fauna and climate.
Cenozoic is characterized by a large number of insects, flying and marine animals. Mammals and angiosperms predominate. It was at this time that all living organisms strongly evolve and are distinguished by a large number of subspecies. Cereals appear. The most important transformation is the appearance of a rational person.
Human evolution. Initial stages of development
The exact age of the planet is impossible to determine. Scientists argue about this topic for a long time. Some believe that the age of the Earth is 6000 thousand years, others that more than 6 million. I believe that we will never know the truth. The most important achievement of the Cenozoic era is the emergence of Homo sapiens. Let's take a closer look at exactly how this happened.
There are a large number of opinions regarding the formation of humanity. Scientists have repeatedly compared the most diverse sets of DNA. They came to the conclusion that monkeys have the most similar organism to humans. It is impossible to prove this theory to the end. Some scientists argue that the human body and pigs are also quite similar.
Human evolution is visible to the naked eye. At first, biological factors were important for the population, and today, social factors. Neanderthal, Cro-Magnon, Australopithecus and others - all these are the phases of human development through which our ancestors passed.
Parapithecus is the first step in the development of modern man. At this stage, our ancestors existed - monkeys, namely chimpanzees, gorillas and orangutans.
The next stage of development was Australopithecus. The first remains found were in Africa. According to preliminary data, their age is about 3 million years. Scientists investigated the find and came to the conclusion that Australopithecus is quite similar to modern man. The growth of representatives was quite small, about 130 centimeters. The weight of Australopithecus was 25-40 kilograms. Most likely, they did not use the guns, since they were never found.
A skilled man was similar to Australopithecus, but, unlike them, he used a primitive tool. His hands and phalanges of the fingers were more developed. It is believed that it is a skilled person - our direct ancestor.
Pithecanthropus
The next stage of evolution was the pithecanthropus, an erect man. Its first remains were found on the island of Java. According to scientists, Pithecanthropus lived on the territory of the Earth about a million years ago. Later, the remains of a bipedal man were found in all corners of the planet. Based on this, we can conclude that Pithecanthropus inhabited all continents. The body of an upright man was not much different from the modern one. However, there were minor differences. Pithecanthropus had a low forehead and pronounced superciliary arches. Scientists have found that bipedal man led an active lifestyle. Pithecanthropus hunted and manufactured simple tools. They lived in groups. So it was easier for Pithecanthropus to hunt and defend themselves from the enemy. Findings in China suggest that they also knew how to use fire. The Pithecanthropus appeared abstract thinking and speech.
Neanderthal
Neanderthals lived about 350 thousand years ago. Found about 100 remains of their life. The Neanderthal skull was domed. Their growth was about 170 centimeters. They had a fairly large physique, well-developed muscles and good physical strength. They had to live in the ice age. It is because of this that Neanderthals learned to sew leather clothes and constantly maintain fire. There is an opinion that Neanderthals lived only on the territory of Eurasia. It is also worth noting that they carefully processed the stone for the future guns. Neanderthals often used wood. From him they created tools and elements for housing. However, it is worth noting that they were quite primitive.
Cro-Magnon
Cro-Magnons had a high growth, which was about 180 centimeters. They had all the signs of a modern person. Over the past 40 thousand years, their appearance has not changed at all. After analyzing the human remains, the scientists concluded that the average age of the Cro-Magnons was about 30-50 years. It is worth noting that they created more complex types of weapons. Among them are knives and harpoons. Cro-Magnons fished and therefore, in addition to the standard set of weapons, they created a new one for comfortable fishing. Among them are needles and much more. From this we can conclude that the Cro-Magnons had a well-developed brain and logic.
The intelligent man built his dwelling place out of stone or tore it out in the ground. The nomadic population for temporary convenience created temporary huts. It is also worth noting that the Cro-Magnons tamed the wolf, turning it over time into a watchdog.
Cro-Magnons and art
Few people know that it was the Cro-Magnons who formed the concept, which we now know as the concept of creativity. On the walls of a large number of caves, cave paintings by Cro-Magnons were found. It is worth emphasizing that Cro-Magnons always left their drawings in hard-to-reach places. Perhaps they performed some kind of magical role.
The technique of drawing drawings by Cro-Magnons was diverse. Some clearly depicted images, while others scratched them. Cro-Magnons used colored paints. Mostly red, yellow, brown and black. Over time, they even began to grind figures of people. You can easily find all the exhibits found in almost any archaeological museum. Scientists note that the Cro-Magnons were quite developed and educated. They loved to wear jewelry made from the bones of the animals they killed.
There is a rather interesting opinion. It used to be that the Cro-Magnons ousted Neanderthals in an unequal struggle. Today, scientists suggest otherwise. They believe that for a certain amount of time, Neanderthals and Cro-Magnons lived side by side, but the weaker ones died from a sharp cooling.
To summarize
The geological history of the Earth originates many millions of years ago. Each era has contributed to our modern life. We often do not think about how our planet evolved. Studying information about how our Earth was formed, it is impossible to stop. The history of the evolution of the planet can bewitch everyone. We strongly recommend protecting our Earth, if only so that after another millions of years the history of our existence would be someone to study.