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Aristotle Theory of Spontaneous Generation
Aristotle was an Ancient Greek philosopher and polymath. As the founder of the Peripatetic school of philosophy in the Lyceum in Athens, he began the wider Aristotelian tradition that followed, which set the groundwork for the development of modern science. Aristotle first compiled and expanded the work of prior natural philosophers and the various ancient explanations of the origin of life leading to the theory of Spontaneous Generation. This theory swayed for as long as two millennia. -
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Francesco Radi
Francesco Redi was an Italian physician, naturalist, biologist, and poet. He is referred to as the "founder of experimental biology", and as the "father of modern parasitology". He was the first person to challenge the theory of spontaneous generation by demonstrating that maggots come from the eggs of flies. He worked thanks to his doctorate in medicine and philosophy in various cities in Italy. A rationalist of his time, he was a critic of verifiable myths, such as spontaneous generation. -
Francesco Redi's experiment and early thoughts about Spontaneous generation
During the middle ages, it was believed that life could appear through spontaneous generation and it was widely held that maggots arose spontaneously in rotting meat. Francesco Redi, an Italian physician, and poet, rejected this idea and wanted to prove its wrongness. To achieve his goal he set out a controlled experiment with jars as it is described in the image. Even though he succeed, he still didn't believe 100% on his results and so didn't was believed in world's population. -
Redi's experiment details
To test the hypothesis, Francesco Redi placed fresh meat in open containers. And the rotting meat attracted flies, and the meat was soon swarming with maggots, which hatched into flies. When the jars were tightly covered so that flies could not get in and didn't appear any maggot. Redi covered the jars with several layers of porous gauze instead of an air-tight cover. Flies were attracted to the smell of the rotting meat, which was soon swarming with maggots, but the meat remained free. -
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John Turberville Needham
John Turberville Needham FRS was an English biologist and Roman Catholic priest. He was first exposed to natural philosophy while in seminary school and later published a paper which, while the subject was mostly about geology, described the mechanics of pollen and won recognition in the botany community. He did experiments with gravy and later, tainted wheat, in containers. This was in order to experiment with spontaneous generation. -
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Lazzaro Spallanzani
Lazzaro Spallanzani was an Italian Catholic priest, biologist and physiologist who made important contributions to the experimental study of bodily functions, animal reproduction, and animal echolocation. His research on biogenesis paved the way for the downfall of the theory of spontaneous generation, a prevailing idea at the time that organisms develop from inanimate matters, though the final death blow to the idea was dealt with by French scientist Louis Pasteur a century later. -
Needham's experiment
Microscopy was invented and a new world of microorganisms was revealed. So scientists started to believe that spontaneous generation was only applied to small organisms. An English clergyman called John Needham claimed that spontaneous generation was true. So he made an experiment that consisted of briefly heating broth to its boiling point to kill microorganisms and pouring it into flasks. He observed living microorganisms in the sealed broth and so he approved spontaneous generation. -
Spallanzani's experiment
Lazzaro Spallanzani was an Italian biologist and physiologist priest who disagreed with Needham's decisions. Spallanzani emptied stock into cups and fixed them. He then prolonged the boiling process in the flasks to eliminate the existing microorganisms. After some time, the stock had no hint of life. Be that as it may, when he unlocked the carafe, microorganisms quickly filled in the stock. He concluded that there was no spontaneous generation and that the microbes came from polluted air. -
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Louis Pasteur
Louis Pasteur was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation, and pasteurization, the last of which was named after him. His research in chemistry led to remarkable breakthroughs in the understanding of the causes and preventions of diseases, which laid down the foundations of hygiene, public health and much of modern medicine. He is regarded as one of the founders of modern bacteriology and microbiology. -
Pasteur's experiment
Famous French scientist Louis Pasteur accepted to recreate the previous experiment. He created bottles with S-shaped, downward-facing necks. After boiling a nutrient-rich broth inside one of the swan-neck bottles, there was no life in the jar for a year. He then broke off the top of the bottle to expose it to the air and trapped particles more directly, and within days, he discovered life forms in the broth. He contemplated that the tainting came from life structures in the air. -
Final conclusions
Pasteur articulated the concept of "Omne vivum ex vivo" in an 1864 lecture. Pasteur described his well-known swan-neck flask experiment in this lecture, stating, " life is a microbe and a microorganism is life. The fatal blow of this straightforward experiment will never heal the doctrine of spontaneous generation. Amazingly, it won't ever have.