Spontaneous Generation
Spontaneous Generation, also known as abiogenesis, was the theory that living organisms could be formed out of nonliving things. This was a popular theory up until the late nineteenth century.
In the fourth century, Aristotle, a Greek philosopher, stated that abiogenesis was one of the four ways of reproduction. The other ways were sexual reproduction with copulation, sexual reproduction without copulation, and asexual reproduction.
Some beliefs about Spontaneous Generation included that snakes could arise from horse hair in stagnant water. Many people also believed that mice could form from decomposing foods that were left out, maggots appeared from rotting meat and mice could come from cheese and bread wrapped in a cloth and left in a corner. The maggots that were appearing in the rotting meat was especially strong evidence for those who believed in abiogenesis.
For many centuries people believed in Spontaneous Generation. However, there were also scientists who did not believe in it, and wanted to prove it as being false. Some of these scientists included Anton van Leewenhoek, Louis Pasteur, Francisco Redi, and Larazzo Spallanzani.
However, in 1859, Louis Pasteur, a French chemist, managed to prove abiogenesis as being false. In the experiment that he conducted, he boiled meat broth in a flask. He heated the neck of the flask until it became bendable. When this happened he bent the neck into the shape of an "S." Because of this, air could enter the flask, however, airborne molecules could not. Due to gravity, these organisms would settle in the neck of the flask. As expected, no microorganisms grew in the flask. When the flask was tilted so that the broth could reach the lowest point in the neck of the flask, it became cloudy with life. This experiment proved both that Spontaneous Generation was false, and that microorganisms were everywhere, even in the air.
In the fourth century, Aristotle, a Greek philosopher, stated that abiogenesis was one of the four ways of reproduction. The other ways were sexual reproduction with copulation, sexual reproduction without copulation, and asexual reproduction.
Some beliefs about Spontaneous Generation included that snakes could arise from horse hair in stagnant water. Many people also believed that mice could form from decomposing foods that were left out, maggots appeared from rotting meat and mice could come from cheese and bread wrapped in a cloth and left in a corner. The maggots that were appearing in the rotting meat was especially strong evidence for those who believed in abiogenesis.
For many centuries people believed in Spontaneous Generation. However, there were also scientists who did not believe in it, and wanted to prove it as being false. Some of these scientists included Anton van Leewenhoek, Louis Pasteur, Francisco Redi, and Larazzo Spallanzani.
However, in 1859, Louis Pasteur, a French chemist, managed to prove abiogenesis as being false. In the experiment that he conducted, he boiled meat broth in a flask. He heated the neck of the flask until it became bendable. When this happened he bent the neck into the shape of an "S." Because of this, air could enter the flask, however, airborne molecules could not. Due to gravity, these organisms would settle in the neck of the flask. As expected, no microorganisms grew in the flask. When the flask was tilted so that the broth could reach the lowest point in the neck of the flask, it became cloudy with life. This experiment proved both that Spontaneous Generation was false, and that microorganisms were everywhere, even in the air.
This image shows Louis Pasteur conducting his experiment. The flask he holds in his left hand is the flask with the "S" shaped neck where the microorganisms would gather.