Archaean era - the beginning of life on Earth

The earliest and most ancient period of development of the earth's crust is the Archaean era. It was at this time in the opinion of scientists that the first living organisms-heterotrophs appeared, which used various organic compounds as food. At the end of the Archean era, the formation of the nucleus of our planet took place, the activity of volcanoes intensively decreased, because of which life began to develop on Earth.

The Archean era began about 4,000,000,000 years ago and lasted about 1.56 billion years. It is divided into four periods: Neoarchae, Paleoarchae, Mesoarchaeus and Eoarchey.

Earth Crust in Archean Era

In the Neo-Archaean period, which took place about 4,000 million years ago, the Earth was already formed as a planet. Almost the whole area was occupied by volcanoes, which erupted in large quantities of lava. Its hot rivers formed continents, plateaus, mountains and ocean basins. The constant activity of volcanoes and high temperatures led to the formation of minerals - ore, copper, aluminum, gold, building stone, radioactive metals, cobalt and iron. About 3.67 billion years ago, the first metamorphic and magmatic rocks (granite, anorthosite and diorite) were formed, which were found in various places: the Baltic and Canadian shields, the island of Greenland, and others.

During the Paleoarchaeus (3.7-3.34 billion years ago), the formation of the first continent, Valbaru, and the single ocean occurs. At the same time, the structure of the oceanic ridges has changed, which has led to a gradual increase in the amount of water and a decrease in the amount of carbon dioxide gas in the Earth's atmosphere.

Then followed Mesoarchey, during which the supercontinent began to slowly split. In Neoarchey, which ended about 2.65 billion years ago, the main continental mass is formed. This fact speaks of the antiquity of all the continents of our planet.

Climatic conditions and atmosphere

The Archean era was characterized by a small amount of water. Instead of a vast single ocean, there were only shallow basins, located separately from each other. The atmosphere consisted mainly of gas (carbon dioxide - the chemical formula of CO2), its density was much higher than the current one. The water temperature reached 90 degrees. Nitrogen in the atmosphere was small, about ten to fifteen percent. Methane, oxygen and some other gases practically did not exist. The temperature of the atmosphere itself, according to scientists, reached 120 degrees.

Archean era: biology

During this era, the birth of the first protozoan organisms occurs. Anaerobic bacteria became the first inhabitants of the Earth. In the Archean era, the first photosynthetic organisms appeared - cyanobacteria (pre-nuclear) and blue-green algae, which began to release free oxygen into the atmosphere from the ocean of the Earth. This contributed to the emergence of living organisms that can survive in the oxygen environment.

But the Archeozoic era is important not only for the appearance of photosynthesis. At this time, there are two more important evolutionary events: multicellularity and sexual process that sharply increased the adaptation to environmental conditions due to the creation of a multitude of chromosomal combinations.