The origin of life was highly speculative until agraduate student at the University of Chicago, Stanley Miller designed and conducted an empirical research project under the guidance of his graduate advisor, Harold Urey. In this classic experiment, the re

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The origin of life was highly speculative until agraduate student at the University of Chicago, Stanley Miller designed and conducted an empirical research project under the guidance of his graduate advisor, Harold Urey. In this classic experiment, the researchers tried to simulate the chemical evolution that generated life. Miller and Urey took a five-liter flask half filled with water and connected it with glass tubing to another flask into which they inserted tungsten electrodes. They then mixed methane,hydrogen, and ammonia into the waterin the lower flask and heated it to induce evapouration, while at the same time subjecting it to continuous electrical chargesthat jumped across the space between the electrodes in the upper flask. The atmosphere was cooled againso that the water could condense and trickle back into the first flask in a continuous cycle. In this way, they sought to recreate conditions in the early atmosphereof earth, which they speculated was probably subjected to powerful electrical storms. In about an hour, the water turned orange. At the end of the first week, they observed that almost 15 percent of the carbon was converted into organic compounds. After several weeks, the liquid in the flask clouded and then gradually turned adark brown. When they analyzed it,Miller and Urey found that it contained alarge number of amino acids, which form one of basic structures of living organisms. They then hypothesizedthat the amino acids they had created in the laboratory might be typical of chemical mixtureof early oceans on earth, and further that additional amino acids could have been added to the mixture in the early oceansby carbon enriched meteoritesor comets.
When the scientific results were popularized, the mixture became known as ' primordial soup'. However, much was still nknown about the process that caude the first cell to develop within the soup.The molecules produced were relatively simple organic molecules, not acomplete living biochemical system. Nevertheless, the experiment established that natural processes could produce the building blocks of life without requiring life to synthesize them in the first place.The experiment served as inspiration for alarge number of further investigations.

The author of the reading passage explains the Miller and Urey experiment that was an attempt to mimic the chemical evolution process that engendered life. It was believed to be a ground breaking experiment and the mixture is called Primordial soup. The lecturer asserts that the present opinion is dubious about the experiment and raises objections to the experiment.

The lecturer states that the Miller experiment was carried out in the lab, where it was subjected to continuous electrical energy. He argues that although it is hypothesized that the earth during chemical evolution process was subjected to powerful electrical storms as simulated in the experiment; however, contrary to the experiment it was intermittent rather than continuous.

The lecturer acknowledges that although the amino acids( which are considered building blocks of life) may have been formed during the chemical evolution process of life generation as replicated in the Miller experiment. Nevertheless, he contends that many researchers believe that it must be a minor contribution , with the possibility of major amino acids being released in the earth by colliding meteorites , which are proved to be rich in these organic compounds. Some researchers believe that early earth was like meteorites and these amino acids were already present. This directly challenges the claim of the experiment mentioned in the passage.

Finally, the lecturer asserts that there are some questions about the amount of oxygen reduced from the experimental mixture, a serious concern since the proportions have to be the same for the simulation to be achieved.

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The author of the reading passage explains the Miller and Urey experiment that was an attempt to mimic the chemical evolution process that engendered life.
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