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Spontaneous generation is a superseded scientific theory that held that living creatures could arise from nonliving matter and that such processes were commonplace and regular. It was hypothesized that certain forms, such as fleas , could arise from inanimate matter such as dust, or that maggots could arise from dead flesh.
By the middle of the 19th century, biogenesis was supported by so much evidence that spontaneous generation had been effectively disproven. Pasteur remarked, about an 1864 finding of his, "Never will the doctrine of spontaneous generation recover from the mortal blow struck by this simple experiment."
Van Leeuwenhoek disagreed with spontaneous generation, and by the 1680s convinced himself, using experiments ranging from sealed and open meat incubation and the close study of insect reproduction, that the theory was incorrect. [25] In 1668 Francesco Redi showed that no maggots appeared in meat when flies were prevented from laying eggs. [26]
Lazzaro Spallanzani (Italian pronunciation: [ˈladdzaro spallanˈtsaːni]; 12 January 1729 – 11 February 1799) was an Italian Catholic priest (for which he was nicknamed Abbé Spallanzani), biologist and physiologist who made important contributions to the experimental study of bodily functions, animal reproduction, and animal echolocation. [2]
From here, is where the study of the origin of life branched. Those who accepted Pasteur's rejection of spontaneous generation began to develop the theory that under (unknown) conditions on a primitive Earth, life must have gradually evolved from organic material. This theory became known as abiogenesis, and is the currently accepted one. On ...
[5] [6] From the two experiments, Pasteur concluded that the atmospheric dust carried germs responsible for the 'spontaneous generation' in his broths. [6] Thus, Pasteur's work provided proof that the emergent growth of bacteria in nutrient broths is caused by biogenesis rather than some form of spontaneous generation.
He then confirmed that the phenomenon existed in the cell of every frog's egg immediately after fertilization, proving that this was a universal phenomenon and finally explaining the reason for the results of tests by Louis Pasteur which had previously proved that there exists no spontaneous generation of life. [3]
Until the 19th century, there was considerable acceptance of the theory of spontaneous generation, the idea that "lower" animals, such as insects or rodents, arose from decaying matter. [10] However, several experiments in the 19th century – particularly Louis Pasteur 's swan neck flask experiment in 1859 [ 11 ] — disproved the theory that ...