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550 BCE
Anaximander Proposes Spontaneous Generation
Anaximander is a Greek philosopher who lived between 610 to 546 B.C. He was the one that first proposed the idea of Spontaneous Generation, the theory that says that life could be generated from non-living objects. This theory was then promoted by Aristotle. -
340 BCE
Aristotle Promotes the Theory of Spontaneous Generation
The Greek philosopher, Aristotle, who lived between 384 to 322 B.C. promoted Anaximander's theory of spontaneous generation. In his book, History of Animals, he states, "...some come from putrefying earth or vegetable matter, as is the case with a number of insects, while others are spontaneously generated in the inside of animals out of the secretions of their several organs." It is Aristotle's writings that eventually influenced the Catholic Church to accept this theory. -
Francesco Redi Attacks
In 1668, Francesco Redi, an Italian biologist, carried out an experiment to disprove the theory of Spontaneous Generation. At that time, it was common to people that maggots would grow spontaneously from rotting meat. To tackle this belief, Redi placed 3 pieces of rotting meet in 3 different jars, one with its lid open, another with its lid sealed, and the third with its opening covered with gauze. As he expected, maggots only grew on the meat in the open container, where the flies could reach. -
John Needham Supports Spontaneous Generation
In 1745, an English clergyman named John Needham carried out an experiment supporting Anaximander's claim. Since it was widely regarded that boiling would kill bacteria, Needham decided to boil chicken meat and place it in a sealed container to see if microorganisms grew. Just as he expected, more bacteria started to form. However, it is important to note that boiling does not kill all bacteria, so the new ones that formed may have just came from the ones that still existed after the boiling. -
Lazzaro Spallanzani Recreates Needham's Experiment
Unconvinced, in 1768, Lazzaro Spallanzani, an Italian biologist, set forth to recreate Needham's experiment. The difference is, though, that this time there was no air inside the container. As a result, there were no microorganisms that grew. However, the limitation to this experiment is that it only showed how nothing could grow in the absence of air. -
Louis Pasteur Settles the Conflict
In 1859, the young chemist, Louis Pasteur, invented a S-shaped tube, in which he connected to a flask with water. This way, air could go into the flask, while other microorganisms could not. He then proceeded to boiled the water to kill the majority of bacteria present. To what he expected, no bacteria grew in the flask. When he removed the S-shaped neck, however, the water inside started teeming with life. The theory of Spontaneous Generation was thus disproved once and for all.
