- What is the origin of life?
- Creationist theory
- Spontaneous generation
- The panspermic theory
- Oparín's theory
We analyze what is the origin of life and the various theories that tried to answer that question. Also, what does science say.
What is the origin of life?
The question as to what is the origin of the life has accompanied the human being since the beginning of civilization itself, and it is one of the great universal mysteries that science has been determined to resolve.
But it has not been easy to find an explanation for a phenomenon that precedes us as species for many billions of years, and of which we have seen, therefore, only a very recent percentage.
The ancient civilizationsendowed with a deeply religious character, they always attributed to their gods the creation of the cosmos, of the Earth and of life itself, through different myths cosmogonic. These mythological stories could have points in common, or differ substantially according to the culture who imagined them.
Such points of view were gradually discarded by empirical thought and scientific, which was holding the existence of some explanation logic and verifiable, which could be accessed through the experimentation and theoretical knowledge.
The great advances in anatomy, chemistry, genetics and especially the studies of Louis Pasteur (1822-1895), Charles Darwin (1809-1882) and Alexandr Oparin (1894-1980) played a major role in understanding that, necessarily, all living beings they come from another previous living being that engendered them.
Today, science and technology that we have have allowed us to look for a satisfactory explanation in the multiple biological evidence of the world, both modern and observable with the naked eye, as well as the ancient one that makes up the fossil record.
Although we have a more or less complete scientific explanation, supported by abundant empirical evidence, there are still unanswered questions and questions that keep scientists on edge.
Next, we will see a review of the main theories about the origin of life that emerged in the history of the humanity.
Creationist theory
The first theories about the origin of life attributed it to the divine will.The first explanations that the human being raised regarding the origin not only of life, but also of the universeThey started from their religious conception of the cosmos. According to this point of view, there were ancient deities, creators, maintainers and destroyers of the universe, responsible for the creation of everything that exists and especially living beings, among which the human being occupied the place of the favorite son.
This approach is contained in its own way in all the great religious texts, such as the Bible, the Koran, the Talmud, the Popol-Vuh, and so on. In them, one or more gods were in charge of creating humanity from inanimate elements, such as mud, corn or clay.
Contrary to what might be thought, such a point of view was held to practically the Modern age, for the big religions monotheists and their respective churches, among which the Catholic Church always played a central role in the West.
According to him dogma Christian, life on Earth was created by God throughout the seven days it took him to make the universe everything of his own free will. Thus also created the human being: Adam, made of clay in his image and likeness, and Eve, created from a rib of Adam. God created their bodies and created their souls, and allowed them to reproduce to populate and work the Earth, making them lords of the rest of the living beings.
Spontaneous generation
The Theory of spontaneous generation arose as a materialistic thought and less guided by Christian religious orthodoxy was imposed in the West, after the collapse of the world feudal of medieval.
Its roots, however, can already be found in various ancient philosophers and naturalists, such as Aristotle (384-322 BC), but its main defenders were thinkers such as René Descartes (1596-1650), Francis Bacon (1561 -1626), Isaac Newton (1643-1727) and the Belgian naturalist Jean Baptista van Helmont (1580-1644).
According to this theory, life constantly originated on Earth, spontaneously, that is, by itself, from waste substances and excretions, such as sweat, urine, excrement and organic material decomposing.
Initially this theory explained the appearance of flies, lice, scorpions and rats and other animals considered pests or pests. Later she was confronted with the fact that these animals reproduced and laid eggs.
Furthermore, from the first discoveries in evolutionary matter, the theory of spontaneous generation held that only the microorganisms they were generated spontaneously, and from them the rest of life evolved.
Spontaneous generation was difficult to refute by science, since deep down it was a theory that could be combined with creationism: if life appeared spontaneously, it could be said that it was the invisible hand of God that made it possible.
Only with Pasteur's experiments was it possible to refute this theory. This French chemist demonstrated the existence of microorganisms in the air that contaminated the substances and they made them ferment. Thus the impossibility for life to be generated magically was understood.
The panspermic theory
This is how the theory that proposes that life has an extraterrestrial origin is known. It was an explanation that emerged at the end of the 19th century, and which attempted to respond to the difficulties in explaining the chemical transit between matter inanimate and living (what creationism attributed to the "divine breath" that breathed life).
To do this, this theory states that organic matter would have reached the planet in a Kite, meteorite or some other type of space transport, either accidental (natural panspermia) or voluntary (directed panspermia).
This position has been widely criticized because it does not really answer the question about the origin of life, but instead moves the question into unknown space.
In addition, it does not respond to how the original microorganisms could survive the cruel conditions of outer space, although it is true that some bacterial species could be "revived" under ideal conditions, after having been subjected to environmental rigors.
This theory was supported by the German biologist Hermann Richter (1808-1876), the British astronomer Fred Hoyle (1915-2001) and especially the Swedish scientist Svante August Arrhenius (1859-1927), who popularized it by winning the Nobel Prize in Chemistry. in 1903.
Oparín's theory
Based on the works of Alexandr Oparin and the understanding of the DNA and the mechanisms of inheritance genetics, theories about the origin of life are guided by a scientific framework, especially biochemical and geochemical.
Scientific theories propose life as the result of a complex and unpredictable series of chemical reactions inorganic that allowed the gradual emergence of the first and primitive forms of life cell phone.
Oparin in his The origin of life on Earth explained that seas primitives of the planet were a warm soup of organic and inorganic substances, which were bonding with each other to form compounds increasingly complex and bulky.
This is how the coacervates eventually appeared: bubbles of primitive substances that allowed the desired substances to pass through their membrane and kept the unwanted ones on the outside, in a kind of proto-cell.
Despite their obvious importance for the creation of a later scientific model, Oparin's theories, supported by the theory of evolution Darwin's and his natural selection, failed to explain the mechanisms by which the transition occurred between the organic but inanimate forms of compounds, and the first forms of life as such.
In successive years, various hypothesis scientific about it:
- World Hypothesis of RNA. According to this position, the creation of genes was the first step towards life, because it allows the complexity achieved to be transmitted to future generations.
- Iron-Sulfur World Hypothesis. It assumes that that first step is the creation of a metabolism to systematize the absorption of energetic substances.