-C. Paula de los Angeles
Since most people do not believe in a strict literal interpretation of the creation of the world in seven days as detailed in the Bible, the question of how life originated from inorganic material continues to puzzles the scientific community. Recent research discoveries are beginning to dispel some of the mysteries. A New York Times article details four scientific advances that have restored faith in a terrestrial explanation for the beginning of life:
1) protocells: Jack W. Szostak, David P. Bartel and P. Luigi Luisi concluded that genetic material and membranes had to evolve together, and not one after the other, after discovering that it was possible to form cell-like structures naturally from fatty chemicals present at the beginning of Earth. In their 2001 paper in Nature, they concluded that the way to make a cell from a protocell would be to combine a protocell and genetic material encapsculated in a cell membrane. If this set-up were advantageous over others, the outcome would be “a sustainable, autonomously replicating system, capable of Darwinian evolution."
2).self-replicating RNA: Dr. Szostak continued these studies, and from the observation that living cells have exclusive mechanisms to admit only the nutrients they need, decided that protocells needed a way to take-in small molecules. Primitive cells would arise from the influx of nutrients that would combine, making it impossible to get back out. Dr. Szostak is confident of such a chemical replicating system. Last month, Dr. John Sutherland, a chemist, demonstrated that such a self-replicating chemical system could exist under the right conditions, that the base and sugar of DNA could be built up as a single unit, and not separate, so the two do not need to be linked.
3) natural synthesis of nucleotides: Dr. Joyce, has demonstrated the possible replicative properties of RNA, the likely predecessor to DNA, in an experiment that successfully developed two RNA molecules that help the synthesis of four kinds of RNA nucleotides.
4)handedness of molecules: Furthermore, other researchers like Donna Blackmond of Imperial College of London has eliminated the impossibility of "original syn", how all amino acids are left-handed and all sugars and nucleotides are right-handed in living cells, but natural cells exist in roughly equal mixtures. The chemists discovered that that the proportions of left-handed and right-handed molecules can be converted to one form by temperature regulation, cycles of freezing and melting.
These recent advances present interesting questions to the idea that the beginning of life originated in water, as Darwin believed. No one knows for sure where the beginning of life originated, though these studies are beginning to shed some light on our origins.
While these advances in the lab are promising, I struggle with the applicability of these results. While they demonstrate possible pathways, it will be difficult to determine for certain, the actual conditions. For one, I think these studies should be admired for their scientific beauty and elegance alone.
Animated video here: exploringorigins.org
News link here: http://www.nytimes.com/2009/06/16/science/16orig.html?pagewanted=1&ref=science