Brenner Science Project
In this project you will learn about the groundbreaking experiments conducted by Stanley Miller and Harold Urey during the 1950's and what has transpired in the search for the origin of life on earth since then.
Assignment:
Answer the following questions as you read the papers and web-resources.
1. It is commonly accepted among biologists and earth system scientists that all living organisms arose from a single common ancestor. Based on your reading of On the origin of Life on Earth (Carl Zimmer, Science, 2009) what is the primary biological evidence for this theory?
2. Based on your reading of From Primordial Soup to the Prebiotic Beach: An interview with exobiology pioneer, Dr. Stanley L. Miller and The Origin of Life on Earth by Leslie Orgel describe some of the hypotheses that were prevalent prior to Miller and Urey's groundbreaking experiments that attempted to explain how life may have arisen on early earth.
3. Describe Miller and Urey's experiment and their results.
4. Were Miller and Urey's results readily accepted by the scientific community at the time? What steps did Miller take to ensure that his conclusions were reasonable and the the extraordinary results were not a product of experimental error and/or contamination.
5. In modern biological systems protein formation always requires the appropriate nucleotide sequence to be present. And nucleic acids (the building blocks of nucleotide sequences) are only synthesized with the help of proteins. This presents a difficult paradox for origin of life theories. Based on your understanding of The Origin of Life on Earth (Leslie Orgel, Scientific American, 1994) describe the "RNA world" hypothesis, including what properties RNA would have to exhibit that it does not exhibit today, and how it obviates the paradox of interdependent protein and nucleotide formation.
6. The researchers who published the 2009 Science paper discovered and re-analyzed the actual samples that Miller and Urey synthesized more than 50 years earlier (which is really quite amazing). Based on your reading of The Miller Volcanic Discharge Experiment (Johnson, et. al., Science, Oct. 2008) and From Old Vials, New Hints on Origin of Life (Kenneth Chang, (New York Times, Oct. 17, 2008) describe what Jonhnson and his colleagues found in the samples that came from Miller's "volcanic apparatus" that simulated volcanic gases interacting with lightning (spark) and explain why these new results are important. (* please note - the 2009 researchers did not re-run the original experiment, that is they did not re-build the reaction apparatus. Rather, they found the actual collected sample residues from Miller and Urey's original experiments (which is extraordinary in itself) and re-analyzed what was in those samples.)
Attachment:- Assignment.rar