-
400
Aristotle
Aristotle argues that spontaneous generation (a.k.a abiogenesis) is on of the four means of reproduction in 400 BC with The History of Animals. The others were sexual reproduction without copulation, sexual reprouction with copulation and budding. To elaborate, he explained that how there were animals that came from parent animals and others that grew spontaneously from inanimate objects.This theory swayed for as long as two millennia. -
Feb 4, 1579
Johannes Baptista van Helmont
Spontaneous generation of mice was claimed by Johannes Baptista van Helmont, a Flemish physician and alchemist. He believed that mice arose when a flask of wheat and old rags was incubated in a warm dark closet. Futhermore, he also claimed that extra mass of the tree was spontaneously generating from another source by using willow trees. -
Fransico Redi
Francisco Redi in 1668 countered to Aristotle’s theory, by demonstrating that maggots arise not spontaneously but from eggs laid by adult flies. Meat covered He placed meat in three flasks, one open, another sealed and the other with a filter. Maggots appeared in the open false, but didn’t appear in the sealed flask or the flask covered by gauze. If spontaneous generation was possible, there would be maggots growing in all flasks; however, only the non-sealed flasks had maggots. -
Invention of the Microscope
In the 1700s the microscope finally became widely used within scientists to prove experiments and to observe small living things within liquids like broth and grave. Smaller microorganisms were found because of the development of the microscope. These microorganisms were never thought to exist before, but they were associated with things like spoiled broth or meat. organism’s sources because they seem to come from nowhere. -
John Needham
In 1745, John Needham, an English clergyman, attempted to prove the validity of spontaneous generation. He challenged Redi’s findings by placing gravy into a bottle, heated it to kill the living organisms inside, then sealed it. Days later, he noticed presence of microbes in the gravy and announced that life can in fact be created from inorganic matter. -
Lazzaro Spallanzani
Lazzaro Spallanzani, a priest believed the experiment conducted by John Needman had its faults. He believed bacteria could have entered the broth immediately after it was boiled. Therefore, he redid the same experiment; however, in a way that didn’t allow bacteria to enter the broth at any time. Even though his experiment’s data showed that there was no bacteria in the flask, the general public still wasn’t 100% convinced. -
Louis Pasteur
The French Academy of Sciences sponsored a contest for the best experiment either proving or disproving spontaneous generation. Pasteur's winning experiment was a variation of the methods of Needham and Spallanzani. He boiled meat broth in a flask, heated the neck of the flask in a flame until it became pliable, and bent it into the shape of an S. Air could enter the flask, but airborne microorganisms could not - As Pasteur had expected, no microorganism grew and the rest is history. -
Parin and Haldane's Proclamation
Even after Louis Pasteur's experiment, Parin and Haldane proclaimed that basic life was produced from ultraviolet light acting on primitive atmosphere of water, ammonia and methane. This is because scientists are still questioning the Origin of Life on Earth, how did we come to be if Spontaneous Generation is false? There hasn't been a solid explanation for that.
