How many years did the living things on Earth evolve?

At present, there are millions of species of organisms on the earth, and the time of origin of each is different. When it comes to all life on Earth, it ultimately originated from primitive life that appeared about 4 billion years ago, and the differentiation and independent evolution of populations formed modern organisms.

The best material for studying the origin of life on earth is fossils, fossils can record information from the birth of the earth to modern times, but due to the distribution of fossils, human beings have found fossils about only a few times, scientists have found several fossils of ancient organisms billions of years ago, and in 2013, an international research team found ancient plankton more than 3 billion years ago in Australia.

fossil, this organism grows about 20 to 60 microns.

London, USA and Norway, 2017.

A team of geologists and paleontologists from other countries in Quebec, Canada.

Some fossils of bacteria dating back to 100 million years have been found in the area, which are a class of archaea that feed on iron, and the cellular structure of some modern archaea that use iron.

It's kind of similar, if you add the organic-rich clumps that appeared before life.

matter, the evolutionary history of life is much closer to the time of the formation of the earth.

There are few fossils of organisms billions of years ago, first, because they are very old, and secondly, there were very few biological species at that time. Geological and paleontological studies can show that from about 4 billion years ago to the present, the variety of organisms has gone from few to many.

However, the time from the generation of life to the history of evolution may be earlier, because the current research reality of life on earth may have undergone a process of "from nothing", which is formed by the free collision reaction of matter, so before the formation of cell structure, there should also be a lot of organic matter that constitutes cells, and after a long period of free collision and evolution, life can reproduce and multiply the material form of life.

If we trace back to the roots, life on earth originated from the first organic matter, and if we count from the birth of living things, the history of life is about 4 billion years. The characteristics of biological adaptation, in turn, will make organisms have the characteristics of independent evolution in different environments, and the result is the differentiation of biological populations and the formation of new independent species, which is the case for millions of organisms in modern times. There are many kinds of modern organisms, and it is basically impossible to completely ** the independent origin process of each organism, but modern scientists have basically determined the evolution process of several major types of organisms and mapped the evolutionary tree of life on earth.

The question of the origin of life on Earth will be a mystery for a long time, and although modern scientists have experimentally verified that organic matter can be produced by the collision of small molecules in nature, they have not been able to explain why organisms chose proteins and nucleic acids as the main constituent substances, and how these two substances are ultimately connected.

Over the past hundred years, they have evolved and changed over a long period of time to form their current form, but their world has been around for a long time.

Tens of thousands of years or even thousands of years, how long people do not have an accurate answer, and human beings are still studying.

1. Pre-life history.

At the beginning of the formation of the universe, carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus and other major elements that make up life were produced through the "big **". Biological monomolecules include amino acids.

Fatty acids, monosaccharides.

High-energy compounds such as purines-pyrimidines, single nucleotides, porphyrins, ATP, etc. Biopolymers refer to proteins and nucleic acids.

High-molecular-weight hydrocarbons are multi-molecular systems formed by the polymerization of biological single molecules.

2. Geology and Biology.

Since the formation of the earth, the geological history can be divided into the following periods: Plutozoan (45-3.8 billion years ago) and Archean.

38-2.5 billion years ago), Proterozoic (100 million years ago), Paleozoic.

100 million years ago), Mesozoic (100 million years ago), Cenozoic (100 million years ago - now).

3. Mankind The formation of human beings is the second major turning point in the development of events on the earth; And life comes from inorganic matter.

The first major turning point was the birth of the middle school. After the first great turning point, the evolution of various organisms is achieved through the process of adaptation to the environment through genetic mutation (natural selection), that is, through the adaptation of genetic factors to the environment.

Summarize the feelings. Because of the unique ability of humans to radically change their environment, they are able to cope well with their surroundings without going through physiological mutations. Living in the Arctic is inseparable from fur, living in desert areas requires water, and living in water depends on fins; All of this can be addressed through the culture created by human beings, that is, through new non-biological pathways.

Inspired IQ is the result of genetic mutations (natural selection). The development of science comes from the accumulation of predecessors, purposeful experiments, systems of cooperation and exchange, inspiration and intelligence, and purposeless production practices. Language originates from the IQ of inspiration, develops and produces practice, inspiration and IQ, perfects and dissolves in science.

The evolution process is as follows:

1. The evolution of invertebrates.

The earliest animals on Earth were single-celled protozoa.

Multicellular animals evolved from primitive single-celled animals. Multicellular animals are generally believed to have originated from primitive flagellates because they have many species that show a tendency to develop into a multicellular state, such as Globula algae, Cavitaria and so on.

2. Evolution of vertebrates.

The evolution of vertebrates can be divided into three stages: evolution in water, evolution from water to land, evolution of amphibians and reptiles, and evolution of birds and mammals.

1. The origin and evolution of fishes.

The primitive cephalic class can be divided into two branches. A more primitive, mandibless, armoured fish, such as the Armoured fish that appeared in the Ordovician of the Paleozoic Era, flourished in the Silurian and Devonian periods, and their bodies were covered with bulky bone armor, which was quickly eliminated because they could not adapt well. Only a few of them, such as the seven-cheek eel and hagfish, survive, and because they have no upper and lower jaws, they have to live a semi-parasitic life.

The other branch produced the upper and lower jaws, which were able to live actively, becoming the ancestors of fishes.

2. The origin and evolution of amphibians and reptiles.

Transitioning from aquatic to terrestrial life, the archaeo-fin fishes had internal nostrils, and the structure of the even-fins was similar to that of the five-toed limbs, and later due to changes in the environment, they gradually became primitive amphibians. The earthworm is the ancestor of the modern anchodae, and the amphibians, another clade of shell vertebrae, evolved into the modern tailed and anopod.

Reptiles were developed at the end of the Carboniferous period from the archaeoptebrate amphibians of the ancient subclass Madontida. The salamander (or Simonsaurus) has many of the characteristics of ancient amphibians, such as the neck is not obvious, but its occipital condyle, spine and appendage bones are similar to those of reptiles, which can be regarded as a type between amphibians and reptiles. Cuposaurs seem to be the backbone of reptilian ancestors, so all kinds of reptiles are directly or indirectly descended from Cuposaurus.

3. The origin and evolution of birds and mammals.

Birds and reptiles have many similarities in morphology, such as dryness, lack of glands, homology of feathers and scales, a occipital condyle in the skull, large amniotic eggs, in vivo fertilization, etc., which can indicate the kinship.

Mammals originated earlier than birds, evolving from primitive reptiles during the Paleozoic Era.

Evolution, in biology, refers to the change of genetic traits in a population from generation to generation.

The so-called trait refers to the expression of genes, in the process of reproduction, genes will be replicated and passed on to offspring, mutations in genes can change traits, and then cause genetic variation between individuals. New traits are transferred through the population as the genes move through the population due to species migration or horizontal gene transfer between species. Evolution occurs when these genetic variations become more common or no longer rare in a population due to non-random natural selection or random genetic drift.

To put it simply, evolution is essentially a change in the frequency of genes in a population.

Chronology of the Earth.

Archean (archean

It is the oldest period of geohistory. From the biological world, this is the primordial.

In the early stages of the emergence of first life and the evolution of organisms, there were only a small number of prokaryotes, and they left only a very small fossil record.

From the perspective of the abiotic world, the Archean is a thin, crustal

The geothermal gradient is steep

Volcanic-magmatic activity is intense and frequent

Rock formations are generally subject to deformation and metamorphism

Both the atmosphere and the hydrosphere lack free oxygen

periods of formation of a series of special sediments;

It was also a period of formation and growth of a silicon-aluminum crust, and an important period of mineralization.

Proterozoic

In the early days, some continental plates with a wide range, large thickness and relative stability have appeared on the surface.

Thus, in terms of lithospheric tectonics, the Proterozoic is more than the Archean shows.

It has a relatively stable characteristic.

The atmosphere of the Late Early Proterozoic already contains free oxygen, and with the.

With the increasing abundance of plants and the intensification of photosynthesis, the oxygen content of the atmosphere continues to increase.

The middle and late Proterozoic algae were already very abundant, which was clearly different from the Archean.

Sinian Period

It is a unique geohistorical stage in the last period of the Proterozoic. From.

From the point of view of biological evolution, the Aurora system is reliable because it contains fossils of metazoans without hard shells.

There are important differences in the Proterozoic of animal fossils;

But with the abundance of fossils of animals with shells.

Compared to the Cambrian, the fossils contained in the Sinian are not only monotonous, but also monotonous

The number is small and the distribution is ten.

Minutes are limited. Therefore, it is not yet possible to use the animal fossils in it for effective biostratigraphic work.

The most prominent feature of the Sinian bioscience is the emergence of a large variety of non-hard-shelled metazoans in the later period, and the appearance of a small number of small animals with shells in the late period. The higher algae flourished further, and some new types of microscopic ancient plants appeared, and the stromatolites tended to flourish in the early Sinian period, and the number and species suddenly declined in the later period.

From the tectonic condition of the lithosphere, it was on the surface during the Sinian period.

There have been several large ones

The continental plate is relatively stable, and the cover is already typical above.