Spontaneous Generation Theory Definition

Aristotle: The spontaneous genesis idea is supported by Aristotle (384–322 BC), a Greek philosopher. If the substance had pneuma (“vital heat”), he believed that life might have arisen from nonliving elements.

Redi’s Experiment: To refute the spontaneous idea, an Italian scientist named Francesco Redi conducted an experiment on a piece of fresh flesh in 1668.

• Redi divided a piece of fresh meat into two jars.
• He left one jar open while covering the other with a cloth.
• After a few days, he saw that the open jar was full with maggots while the covered jar was empty.
• Maggots were also discovered on the external surface of the fabric that had been used to cover the jar.

Redi demonstrated that maggots formed from fly eggs in this experiment, proving that the spontaneous generation idea was incorrect. Because nonliving cells gave rise to living cells, according to this hypothesis.

John Needham’s Experiment: Later, John Needham, an English scientist, disproved Redi’s experiment by putting broth or gravy in a bottle, heating it to destroy the indie’s germs, and then sealing it. He discovered life within the bottle after a few days and said that life originates from nonliving cells ( In actuality, he did not heat it long enough to kill all the microbes).

Spallanzani’s Experiment: Lazzaro Spallanzani, an Italian scientist, used both Needham and Redi’s experiments to create his own.

• Spallanzani carried out her experiment by dividing soup into two bottles.
• He then brought both broths to a boil in the bottle.
• Then he closed the first bottle and left the second one open.
• After a few days, he saw that the open bottle had life whereas the sealed bottle had none.
• Despite the fact that his experiment was successful, experts of the time noticed that Spallanzani had deprived the closed bottle of air, which was considered to be required for spontaneous production. His assertions were dulled by a vigorous response.

Pasteur’s Experiment: Louis Pasteur, a French scientist, accepts the challenge and conducts his spontaneous generation experiment.

• He created numerous bottles with S-curved necks, commonly known as gooseneck flasks, that were angled downward to prevent extraneous elements from entering via the air.
• He then filled one goose-neck bottle with nutrient-rich soup.
• After that, he cooked the soup inside the bottle and sealed it for a year.
• After a year, there was no sign of life in the jar.
• Then he shattered the top of the goose-neck bottle and exposed it to the air.
• After a few days, he saw the soup had life in it.
• He noted that there were no living forms in the soup until the barrier was removed from the bottle, because airborne particles and dust were caught in the bottle’s S-shaped neck.
• He confirmed that the pollution was caused by airborne living forms. He disproves the spontaneous generation idea with this experiment.

John Tyndall:

• In 1876, an English physicist named John carried out an experiment to back up Pasteur’s findings.
• He devised a device to demonstrate that particulate matter is carried by air.
• He demonstrated that clean air is free of germs by his experiment. There were no microorganisms produced when this clean air was put into life-supporting medium.