A brief description of the history of the development of life on the earth, and what has been experi

It consists of inorganic small molecules, organic small molecules (polymerization), organic macromolecules, and multimolecular systems (evolution) of primitive life.

It has been about 100 million years since the birth of the Earth to the present day. Life on Earth has undergone a long evolutionary process from scratch, from simple prokaryotic single-celled organisms to complex eukaryotic multicellular organisms. The emergence of life on earth has its own chance and its inevitability.

The early evolution of the stars and the formation of the solar system gave the planet Earth a special interstellar position and material composition. The early environment of the earth was suitable for the emergence of life, and the activities of life on the earth also changed the environment of the earth. The environment is closely related to life, and the evolution of organisms is the result of the co-evolution of organisms and the environment.

If we count from the oldest known fossils of organisms on Earth (about 3.5 billion years ago prokaryotic fossils), the evolutionary history of life on Earth accounts for nearly 6 7 in the Precambrian. It should be said that a series of "milestone" events in the history of biological evolution occurred during this geological history. Primitive life originated between 3.5 billion and 4.6 billion years ago, and also gave rise to simple ecosystems; the emergence of eukaryotic life 2.7 billion years ago; From the late Mesoproterozoic to the Neoproterozoic, there was the early differentiation of multicellular animals and multicellular plants, as well as the evolution of complex ecosystems.

Early Earth.

The emergence of biological multicellular cells should be the result of the co-evolution of the environment and organisms in the early days of the earth. Cyanobacteria and bacteria were the main players in changing the early Earth's environment, they appeared 3.5 billion years ago, occupied nearly 2 billion years of life on Earth, and the stromatolite-microbial mats formed by cyanobacteria and bacteria were widely distributed in the oceans at that time, and they fixed CO2 in the atmosphere in the lithosphere while releasing oxygen. But the early atmosphere and primordial oceans contained large amounts of reducing material, coupled with strong volcanism, the free oxygen produced by cyanobacterial photosynthesis did not accumulate in the atmosphere quickly.

After nearly 1 billion years of accumulation, about 2.2 billion years ago, the earth's atmosphere finally contained a certain amount of free oxygen and formed an ozone layer, and aerobic eukaryotic single-celled organisms also evolved from prokaryotes to appear in the ocean at that time.

Terrestrial plants evolved about 100 million years ago from certain algae that live in the oceans; The most primitive types of vertebrates can be traced back to the ancient oceans hundreds of millions of years ago; Invertebrates predate the history of vertebrates by at least 20 million years; The macroalgae in the oceans have a longer evolutionary history, and their ancestors may have lived in the ancient oceans 2 billion years ago. Some prokaryotic life such as bacteria, cyanobacteria have lived on Earth for more than 3.5 billion years.

Today, industrious hands are peeling open this ancient rock formation, looking for the traces left by life over hundreds of millions of years, and reading the chapter of life evolution with wisdom.

How did the origin of life on Earth begin, and how did life evolve?

The unsolved mystery of the origin of life on Earth. This is how one of our life on Earth came to be.