The main stages in the development of life on Earth: table

There is a whole complex of sciences that study the main stages of the development of life on Earth, all of them consider this question from many perspectives, because this is a fundamental problem of natural science. The importance of paleontology, studying the remains of plants and animals of past eras, is very important, it is directly related to the study of the evolution of the world.

This science studies the main stages of the development of life on Earth by reconstructing the appearance, external similarities and differences, the way of life of prehistoric, extinct animals and plants, and the approximate time of existence of one or another species is also determined. But paleontology could not exist as a separate science without many others supporting it; this science is at the junction of biological and geological disciplines. The main stages of the development of life on Earth are recreated with the help of such disciplines as:

• historical geology;
• stratigraphy;
• paleography;
• comparative anatomy;
• paleoclimatology and many others.

All of them are interconnected, without one the others cannot exist.

Geological time

To highlight the main stages in the development of life on Earth, it is necessary to have an idea of ​​such a concept as geological time. How did people manage to isolate some temporary stages? The whole secret lies in the study of rocks. The fact is that rocks that arose at a later time are superimposed on top of those that existed previously. And the age of these layers can be determined by studying the remaining minerals in them.

Among all their diversity, the so-called governing minerals, which are the most numerous and widespread, stand out. Unfortunately, with the help of rocks it is impossible to establish the absolute age, but scientists do not stop here, extracting this knowledge from volcanic rocks. As you know, they arise from magma. So the main stages of the development of life on earth are distinguished.

Briefly, the process of determining the absolute age of volcanic rocks looks like this: igneous rocks contain some elements, if you determine their content in the rock, then you can accurately determine the absolute age of the rock. Of course, errors are possible, but they do not exceed five percent. In addition, the age of our planet is also determined, all scientists adhere to their numbers, but the generally accepted value is five billion years. Now let us single out the main stages in the development of life on Earth, the table will be a good helper in this case.

Eras, Eras, and Periods

In total, paleontologists distinguish five stages or, in other words, eras, each of which is divided into periods, they all consist of eras, and the last of centuries. The Archean and Proterozoic eras are the most ancient times, which span about three billion years. They are distinguished by the complete absence of vertebrate and terrestrial plants that appear in the "era of ancient life", capturing over three hundred million years. Next comes the “era of middle life”, the Mesozoic (one hundred seventy five million years), its distinguishing features are the development of reptiles, birds, mammals, plants, both flowering and angiosperms.

The most recent, fifth, era is Cenozoic, it is also called the “era of new life”, it began seventy million years ago, and we still live in it. This era is characterized by the rapid development of mammals and the advent of man. Now we have examined the stages of the development of life on Earth briefly, we propose to consider each era separately.

Archean era

This stage covers the interval from three thousand nine hundred to two thousand six hundred million years ago. Some sedimentary rocks, that is, formed by particles of the aquatic environment, remained in Africa, Greenland, Australia and Asia. All of them contain:

• biogenic carbon;
• stromatolites;
• microfossils.

Moreover, the origin of the latter in this era is not entirely clear, for example, in the Proterozoic they are associated with cyanobacteria. In the Archean era, all organisms belonged to prokaryotes, and sulfates, nitrates, nitrites, and so on served as a source of oxygen. All existing organisms on the planet outwardly resembled mold films, mainly located at the bottom of reservoirs, in volcanic regions.

Proterozoic era

It is important to mention that this era is also divided into periods, of which there are three. In addition, this is the longest period of our history (approximately two million years). If we consider the boundary of this era and the Archean, then it was during this period that our planet changed dramatically, redistributed land and water expanses. The earth was an icy desert, but at the end of this period the percentage of oxygen reached one percent, which contributed to the sustainable functioning of unicellular organisms, bacteria and algae developed.

At the end of the Proterozoic, multicellular animals formed, this period also has the name "century of jellyfish." Unicellular organisms are being replaced by multicellular ones, which qualitatively change the composition of the atmosphere, which contributes to the development of life on our planet.

Paleozoic

It includes as many as six periods, the first half is called the Early Paleozoic, and the second - late. The Early and Late Paleozoic are distinguished by fauna and flora.

At the first stage, evolution can be traced exclusively in the underwater world, the settlement of land began only in the Devonian, which belongs to the Late Paleozoic.

Mesozoic era

We are now moving on to the most interesting era, a rich, mysterious and diverse life that has evolved over about one hundred eighty-five million years. As can be seen from the table, it is also divided into three periods. The Cretaceous, in comparison with the Jurassic and Triassic, is the longest (seventy-one million years).

As for the climate, it all depends on the location of the continents. Differences from our climate are that:

• he was much warmer than modern;
• There were no temperature differences between the equators and the poles.

In addition, the air was humid, which contributed to the rapid development of living organisms.

If we turn to fauna issues, the most unique group is the well-known dinosaurs. They took dominant positions over other life forms due to the structure of their body, physiological data and reaction.

So, analyzing the question of what are the main stages in the development of life on Earth, we have identified five steps. For the full picture, it remains to consider one more. We offer to start right now.

Cenozoic era

This is a new era that continues to this day. Continents have acquired a modern look, the last dinosaurs have disappeared, plants and animals that are quite familiar to us prevail on Earth. We considered the main stages of the development of life on Earth briefly, disassembled all the steps separately, and our goal was achieved.