We explain what the Theory of Spontaneous Generation is, which thinkers supported it and how it was refuted.
What is the Theory of Spontaneous Generation?
The Theory of Spontaneous Generation was the name given to the belief that certain forms of animal and plant life arose automatically spontaneous, from organic matter, inorganic matter or some combination of both.
This theory was in force for many centuries, since Antiquity. Although it is a hypothesis that could never be proven scientifically, many believed they could verify it through direct observation.
Aristotle, the Greek philosopher, believed in this theory. It was also accepted and supported by thinkers of the 17th and 18th centuries such as Sir Francis Bacon, René Descartes and Isaac Newton, who were unaware of the world of microbiology. It applied to small creatures held by pests or parasites, such as flies, lice, ticks and even mice.
The belief was that if the correct items (say: sweaty underwear and wheat) were left in a container, some type of animals (say: mice) would be found in their place after a certain time.
This theory about the origin of life did not contradict conventional reproduction since the creatures obtained by spontaneous generation were as perfect and identical as those born from sexual reproduction.
In this way, it could be argued that in the decomposed meat, the excrement or the very entrails of the human being, various forms of life occurred by spontaneous generation, instead of thinking that they had somehow gotten there.
See also: Oparin theory
Refutation of the Theory
The Theory of Spontaneous Generation was refuted through three specific experiments:
- Redi's experiment (1668) Carried out by Francesco Redi, an Italian doctor, who doubted that insects could arise spontaneously from putrefaction, and assumed that at some point some adult insect must deposit eggs or larvae on the decomposing matter. To verify this, he placed three pieces of meat in three different containers: one of them open and the other two sealed with gauze that allowed air to enter the jar but not the adult flies. After time passed, there were maggots in the exposed meat and not in the sealed ones, although they did find fly eggs on the gauze.
- Spallanzani's experiment (1769) Later developed by the Catholic priest and naturalist Lázaro Spallanzani, it was a kind of prelude to pasteurization. The Italian placed meat broth in two containers, after having heated them to a temperature that killed the existing microorganisms and having sealed it hermetically in the container. Thus he demonstrated that microorganisms are not born spontaneously from matter, but come from other microorganisms.
- Pasteur's experiment (1861) Developed by the Frenchman Louis Pasteur, father of the food preservation technique known as pasteurization, it consisted of the introduction of meat broth into two distillation cylinders with long, curved mouths (in the shape of an “S”), which is made finer as it ascends. The shape of the tube allowed air to enter, but caused the microorganisms to stay at the bottom of the container, without accessing the meat. Thus, he heated the broth until it was sterilized and simply waited: after several days, there were no signs of decomposition, after which Pasteur proceeded to cut the mouth of the container and there, shortly after, decomposition did occur, thus demonstrating that the microorganisms They came from other microorganisms and that, in general, every form of life comes from another form of life that precedes it.
You may be interested in: Decomposer organisms
References
- “Spontaneous generation” on Wikipedia.
- “The origin of life; theory of spontaneous generation” (video) in TICS in your life.
- “The theory of spontaneous generation” in the Virtual Science Museum.
- “Spontaneous generation” in Lumen Learning.
- “Spontaneous generation” in Biology Dictionary.
- “Spontaneous generation (biological theory)” in The Encyclopaedia Britannica.
