FREE ESSAY ON THE DISPROVAL OF SPONTANEOUS GENERATION

THE DISPROVAL OF SPONTANEOUS GENERATION

From the beginning of time it was believed that living things could come from nonliving
things. This process was known as spontaneous generation. However, in the middle of the
17th century and then through the next 100 years, this idea was disproved by three
important experiments. We now know that a nonliving object or group of objects can not
turn into a living organism. Spontaneous generation is impossible in the atmosphere that
we have today.
In the early 1600's, people believed that living organisms could evolve from nonliving
organisms. They proved this by saying that if a piece of meat was left out uncovered,
that maggots would appear in a few days. These worms did not come from anything that they
could see, so they assumed they came from the nonliving meat. In 1668, a man named Redi
designed and completed an experiment that showed how this was not true. He took two
pieces of raw meat, and left them out. He covered one so that nothing could get in, and
left the other one open. The open one grew maggots, and the covered one did not, proving
that the dead meat did not produce the worms as they had previously thought.
In the 1700's a man named Spallanzani proved Redi's idea to a further extent. He noticed
microbial growth on boiled pond water after being exposed to the air. To prove that this
growth came from something living in the air, and not from the nonliving water, he
designed an experiment. He boiled pond water to kill all the microbial growths. He then
poured that water into two separate test tubes. He sealed one so that no air could get
in, and left one open to the air. The one that was left open slowly became more and more
cloudy with microbial growths. The sealed tube stayed as clear as it had been when it was
boiled. This experiment proved that the growths could not come from nonliving organisms,
but had to have been transported there through the air. When Spallanzani presented his
results to the public, he was criticized. Other scientists said that he made the air
unfit for living growth, and that they needed the air to change from nonliving to
living.
Pasteur did the third experiment, in 1862. He took Spallanzani's experiment, and the
critic's statements, and combined the two. He boiled pond water to kill all the living
organisms. He poured that water into two curved neck flasks. He then proceeded to break
the neck off of one of the flasks at the base. The flask with the broken neck started to
become cloudy in a few days, however, the other flask continued to stay clear. He proved
that the microbial organisms could not come from something nonliving. The curve in the
neck of the flask allowed air to flow in, however, it caught all the microorganisms in
the neck.
Spontaneous generation is the idea that a living organism can come from something
nonliving. This idea was entirely believed until the mid 1800's. Three important
experiments helped to disprove this idea. Due to the work of three men, we now have the
knowledge that living things can only come from other living things in our environment.