Primary Broth: What Does The Theory And Experiments Consist Of

The theory of the primary soup , also called primitive, primitive, primitive soup   or primordial soup, seeks to define the origin of life on Earth; It was developed by the Soviet scientist Alexander Oparin.

At the same time, in the 1920s the British scientist JBS Haldane was creating a very similar theory, and it was the latter who coined the term “soup” to refer to it.

Primary broth

According to this theory, life on Earth originated in a chemical environment that existed approximately 3.8 billion years ago. Although it is not possible to prove the veracity of this hypothesis, since the conditions of the Earth at that time are not completely known, experiments have been carried out to identify how possible an event of this nature is.

However, the origin of life on Earth remains ambiguous. Many scientists support various theories, although none have been fully proven.

What is the theory about?

The primary broth theory is based entirely on the concept of abiogenesis. Abiogenesis is a process by which, in theory, living organisms can be created as a consequence of chemical reactions generated by non-living compounds.

Simply put, it is about the creation of life through chemical reactions. It is an evolutionary concept that defines the origin of life by reactions of inorganic matter .

The primordial soup theory holds that life was generated in an ocean or well of water that existed on Earth 3.8 billion years ago. By then, the atmospheric conditions of the planet and its chemical composition were in a much more chaotic state than today.

At that time there were no plants or life on the planet. According to the theories of Oparin and Haldane, the Earth had a reductive atmosphere . This means that it had very low amounts of oxygen, or is even considered to have no oxygen at all.

Therefore, the primordial soup theory (also known as the Oparin-Haldane Hypothesis) holds that life on the planet was generated by the chemical reaction of carbon, hydrogen, water vapor, and ammonia.

Historical background and Darwinian belief

Since the time of the Greek philosopher and scientist Aristotle, it has been theorized about the possibility that life on the planet had been originated through a process of abiogenesis. Aristotle himself had a simple theory regarding this: he compared the emergence of worms in decomposed substances with the spontaneous creation of life.

Aristotle’s concept (which originated in the 4th century BC) ceased to be accepted in the middle of the 17th century, when an Italian scientist showed that larvae in garbage are generated only when flies come into contact with it.

The concept of the Italian, whose name was Francesco Redi, fully supported the idea that every living form should be generated from another living form. This concept is what is called biogenesis; the creation of life based on life itself.

Later it was experimented with the origin of microbes in environments that were not exposed to water. As the experiment failed, the possibility of an emergence through abiogenesis was ruled out.

However, Charles Darwin did theorize about the possibility that life could have originated in a well, when the Earth was in a much more primitive state. He considered that, under a series of determined conditions, it is possible that life is generated through abiogenesis.


To test the theory of Oparin and Haldane, two main experiments were carried out that have served as the basis for giving longevity to the ideas of both scientists. The results are inconclusive, but prove that they may have a certain level of veracity.

Miller and Urey experiment

This experiment is considered one of the classic tests of the investigation of abiogenesis processes. It was carried out in 1952 by University of Chicago professor (and forerunner of the atomic bomb) Harold Urey; and one of his students, Stanley Miller.

The experiment was carried out using methane, hydrogen, water, and ammonia. All compounds were sealed within a sterilized environment, where everything was controlled to simulate conditions on Earth millions of years ago.

The evaporation of the water was induced and electricity was used to simulate the possible impacts of atmospheric electrical discharges.

This experiment managed to produce a variety of amino acids that partially supported the primordial soup theory and thus the process of abiogenesis.

They were not conclusive evidence, but they definitely indicated a latent possibility that life on Earth could have originated in this way.

However, other scientific tests that were carried out years after the experiment concluded that the Earth’s atmosphere at that time may have been very different from how it was proposed in the Miller and Urey experiment. This affected the credibility of the theory.

Joan Oró’s experiment

Oró was a French scientist who carried out an experiment in 1961. He determined that nucleobase adenine (a fundamental component of nucleic acids present in living organisms), could be created from hydrogen and ammonia in a solution of water.

His experiment stands as a banner of prebiotic chemistry to this day, partially supporting the prebiotic soup theory.

Oró also proposed the idea that the fundamental components of life reached Earth via comets and asteroids that collided with the planet millions of years ago. His idea is widely accepted; in fact, this is believed to be the most feasible way in which life originated on Earth.

This theory was also generated in 1961, when he carried out his experiment. In fact, according to Oró, the components by which life was generated through abiogenesis reached the prebiotic water through comets that impacted the planet.


  1. The secret ingredient to early life’s primordial soup: Thickener, Sarah Kaplan for the Washington Post, October 10, 2016. Taken from
  2. Finding the Origin of Life: The Primordial Soup Theory Explained, (nd). Taken from
  3. Primordial Soup, Wikipedia in English, March 29, 2018. Taken from
  4. Miller-Urey Experiment, Wikipedia in English, February 22, 2018. Taken from
  5. Joan Oró, Wikipedia in English, November 26, 2017. Taken from
  6. Harold Urey, Wikipedia in English, April 2, 2018. Taken from

Add a Comment

Your email address will not be published. Required fields are marked *