Origin of Life (Meaning and Explanation)

We analyze what the origin of life is and the various theories that tried to answer that question. Also, what does science say.

What is the origin of life?

The question regarding the origin of life has accompanied human beings since the beginning of civilization itself, and It is one of the great universal mysteries that science has endeavored to solve.

But it has not been easy to find an explanation for a phenomenon that precedes us as a species by many billions of years, and of which we have therefore seen only a very recent percentage.

ancient civilizations endowed with a deeply religious character, always attributed the creation of the cosmos, the Earth and life itself to their gods through different cosmogonic myths. These mythological stories could have points in common, or differ substantially according to the culture that imagined them.

Such points of view were gradually discarded by empirical and scientific thought, which maintained the existence of some logical and verifiable explanation, which could be accessed through 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 come from another previous living being that generated them.

Today, the science and technology we have have allowed us to seek a satisfactory explanation in the multiple biological evidence of the world, both the modern and observable with the naked eye, and the very ancient 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 issues which keep scientists in suspense.

Next, we will see a review of the main theories about the origin of life that emerged in the history of humanity.

The creationist theory

origin of life creationism — The first theories about the origin of life attributed it to divine will.

The first explanations that human beings proposed regarding the origin not only of life, but also of the universe, 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.

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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, etc. In them, one or more gods were in charge of creating humanity from inanimate elements, such as mud, corn or clay.

Contrary to what one might think, such a point of view It was sustained until practically the Modern Age by the great monotheistic religions and their respective churches, among which the Catholic Church always played a central role in the West.

According to Christian dogma, life on Earth was created by God throughout the seven days it took to make the universe all by his own will. This is how he also created the human being: Adam, made of clay in his image and likeness, and Eve, created from Adam's rib. 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 emerged as materialistic thinking less guided by Christian religious orthodoxy prevailed in the West, after the collapse of the feudal world of the Middle Ages.

Its roots, however, can already be found in various philosophers and naturalists of antiquity, 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 originated constantly on Earth, spontaneously, that is, by itself, from waste substances and excretions such as sweat, urine, excrement and decomposing organic matter.

The panspermic theory

origin of life panspermic theory — The theory of panspermia maintains that life comes from outer space.

The theory is thus known that proposes that life has an extraterrestrial origin. It was an explanation that emerged at the end of the 19th century, and that attempted to respond to the difficulties in explaining the chemical transit between inanimate and living matter (which creationism attributed to the “divine breath” that breathed life).

To do this, this theory states that the organic matter would have reached the planet in a comet, meteorite or some other type of space transport, whether accidental (natural panspermia) or voluntary (directed panspermia).

This posture has been widely criticized because it does not really answer the question about the origin of life but rather moves the question into unknown space.

Furthermore, it does not answer how the original microorganisms were able to survive the cruel conditions of outer space, although it is true that some bacterial species could be “revived” in 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

origin of life oparin theory — The coacervates were bubbles with a semipermeable membrane, similar to proto-cells.

Based on the work of Alexandr Oparin and the understanding of DNA and the mechanisms of genetic inheritance, theories on the origin of life are guided by a scientific framework, especially biochemical and geochemical.

Scientific theories propose life as a result of a complex and unpredictable series of inorganic chemical reactions that allowed the gradual emergence of the first and primitive forms of cellular life.

Oparin in his The origin of life on Earth He explained that the planet's primitive seas were a warm soup of organic and inorganic substances, which were linked together to form increasingly complex and voluminous compounds.

So eventually the appearance of coacervates was reached: bubbles of primitive substances that allowed the passage of the desired substances through their membrane and kept the unwanted ones out, in a kind of proto-cell.

Despite their obvious importance for the creation of a later scientific model, Oparin's theories, based on Darwin's theory of evolution and natural selection, failed to explain the mechanisms by which the transition between organic forms occurred but inanimate compounds, and the first forms of life as such.

In successive years, various scientific hypotheses were developed in this regard:

RNA World Hypothesis 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 this first step is the creation of a metabolism to systematize the absorption of energy substances.