The development of the science from Aristotle to Pasteur



The contributions against the spontaneus generation

The theory that every livings comes from others of the same species has been acquired from the men of the past, for degrees. The studies were made also thanks to the invention of the microscope by Leeuwenhoek. Francesco Redi, scientist who lived in XVII the century, was the first one to demonstrate that ' animaletti' that they form themselves on the meat come from the eggs that the flies place on the meat.
After there was the discovery of the protozoans, the argument that existed one spontaneous generation returned outside. Spallanzani demonstrated that also the microscopical livings develop themselves from other livings and not from the contained substances in the infusions. Subsequently with the discovery of the bacteria Pasteur'll say its opinion against the spontaneous generation. Finally with the discovery of the virus was understood how much little was the difference between virus (the livings), and some chemical substances (the enzymes).
Here the problem is more complicated and difficult because the virus need of the participation of the cells of the organism that accommodates them to reproduce.


Now we do not believe to the spontaneous generation because we know that living frogs, flies, worms and other beings do not form themselves from the mud but from other frogs, flies and worms.

Thanks to the experiments of Redi the metamorphosis of the bugs have been discovered that it has been studied in deep way in the successive centuries.
Moreover the ' spontaneous generation ' is a nonexistent hypothesis also for the microscopical living beings, like Spallanzani demonstrated through him experiments on the infusions.

The consequences of Spallanzani's and Redi's experiments have repercussions on us about the conservation of foods: the meat are conserved in the refrigerator at low temperatures, the water are conserved in closed bottles.

All this has been possible thanks to their studies and those of others, like Pasteur that demonstrated that also the bacteria derive from other livings of the same species.

Some problems there will be after the discovery of the virus: the problem of the ' spontaneus generation' will be still debatable even if the scientists will understand like the virus succeed to reproduce themselves to use the organisms that accommodate them.