The Theory of Spontaneous Generation is a theory that was commonly held up until it was disproved around the 18th century. Many researchers advocated for the theory of Spontaneous Generation but it wasn’t until a few pioneering experiments that it was finally disproved and expelled from common scientific thought.
What Is Spontaneous Generation?
Spontaneous Generation is a theory on how living organisms are formed. The theory claimed that living creatures can be created from nonliving matter. It was argued that living things spontaneously generated from nonliving matter and that this was a common thing that happened frequently.
There were many early philosophers with different theories on how living organisms were developed. It was Aristotle who summarized and expanded on the work of these early philosophers to put forth the theory of spontaneous generation.
In addition to Aristotle’s arguments for spontaneous generation, there were many modern experiments advocating for the theory. One famous experiment that was conducted by John Needham showed that after boiling a flask of broth and allowing the flask to sit sealed for three days, organisms appeared in the flask. He argued strongly that since boiling would kill any organisms, and the flask was sealed, these organisms spontaneously generated.
When Was the Theory of Spontaneous Generation Finally Disproved?
Spontaneous Generation had many critics. One strong critic of the theory named Lazzaro Spallanzani conducted an experiment that contradicted the findings of John Needham. By this time of Spallanzani’s research in 1745 there were already many critics of spontaneous generation.
It was Louis Pasteur’s experiment in 1859 that is seen among many as the point where spontaneous generation was finally disproved.
Scientist Who Disproved the Theory of Spontaneous Generation
Louis Pasteur is widely seen as the scientist who finally disproved of spontaneous generation. In his experiment he boiled beef broth in a “swan-neck” flask. A “swan-neck” flask is a flask that has a long bending neck that prevents the contents from being exposed to air. In his experiment the boiled flask showed no microbes. However if the neck of the flask was broken off after boiling, the mixture became cloudy and showed microbial contamination. He concluded that because the sterile flask showed no microbes, spontaneous generation must be false.
Other experiments like Needham’s that argued for spontaneous generation were flawed because they allowed the contents to become contaminated by the air. Louis Pasteur’s experiment was more controlled and showed the flaws of this earlier research.
Sources:
https://en.wikipedia.org/wiki/Spontaneous_generation
https://www.britannica.com/biography/Louis-Pasteur/Spontaneous-generation
