Question

Compare spontaneous generation and biogenesis. What were the contributions of Needham, Spallanzani, Virchow, and Pasteur

Answer 1

Spontaneous generation is an obsolete theory, held by the Ancient Greeks, that proposes the origin of living organisms from nonliving matter, such as the generation of flies from rotting meat.

On the other hand biogenesis the production of a new living organism, it stipulates the origin of living organisms by another living organism.

Needham carried out an experiment that favored the theory of spontaneous generation, he boiled a piece of meat to eliminate al possible microorganism and placed on a container. Because he thought that air was necessary for life he didn't seal the container completely. After some time had passed, he was able to appreciate cellular colonies on the container.

Needhan concluded that his experiment didn't contradict the theory of Spontaneous generation.

Spallanzani designed experiments in order to refute those carried out by Needham. His experiments where similar ot those done by Needham, but Spallanzani boiled the meat for longer periods of time and took special care to seal the containers completely.

Spallanzani didn't find any colonies or proof of living organism, refuting Spontaneous generation.

Virchow contributed to the development of the widely accepted "Cell Theory", mostly with the concept of all cells being originated by other cells.

Louis Pasteur thought that the skin of grapes was the natural source of yeast, therefore sterilized grapes or just grape juice could not ferment and produce wine. Pasteur drew wine from grapes with sterilized needles and covered grapes with a sterilized cloth with the purpose of eliminating the yeast in the skin of the grapes. He found out that in these conditions he couldn't make wine.

Pasteur performed a number of different experiments that disproved Spontaneous generation.