The Origins of Life
Before any speculation toward the origin of biotic forms, what was present at the formation of the earth that could result in inorganic, then organic, and later biotic creatures? Early atmospheric conditions have been theorized to be present due to planetesimal collisions releasing gases present in the Earth, after the initial atmosphere of Hydrogen and Helium escaped Earth’s gravity assisted by heat energy. The earlier atmosphere is believed to have consisted mainly of carbon, hydrogen, nitrogen, and oxygen (bonded to other elements) in such forms as CO2/CO, N2, and H20. Stanley Miller, through experimentation, shows that given an energy source like heat or electric charge it is possible to form reactions that create complex molecules, and through subsequent experiments nucleic acids like adenine were even formed. This is the premise for the “hot” theories of the origin of life. Given there are many derivative possibilities like process evolution, chemoautotrophic, and photoautotrophic origins, the basis is that given an energy source (heat) basic elements can form and break bonds to become increasingly complex.
Given the theories have technically been progressing since 1922 and A.I. Oparin’s hypothesizing, the major strides have been in recent research. Through studies of volcanic activity, fossils, and archaebacteria, speculation leans heavily toward evidence provided by “hot” theory experiments. Given that it is quite plausible and possible that the early earth had the suggested “hot” environment providing heat and monomers that can combine to become polymers, the main step to come into question is, when did these polymers amount to life? “Life for Dummies” would suggest that life requires a way to replicate (RNA/DNA), which involves metabolic pathways like those involving acetyl-CoA. This is the point at which most theories diverge. How were these processes created?
Gunter Wachtershauser’s experiments forced the scientific community to recognize that life originating in “hot” conditions was a plausible theory. Wachtershauser understood that molecules needed a meeting place to be able to form and he proposed that the surface of iron-sulfur minerals and pyrite proved to be very favorable. He was able to prove that the driving force in the creation of amide bonds could be pyrite formation. Using conditions similar to that of volcanic vents Wachtershauser and Claudia Huber joined two carbon atoms to form activated acetic acid and eventually was able to link amino acids into short peptides (Hagmann 2006). Since Wachtershauser's discovery further experiments have been conducted which support his theory.
One experiment supports that under hot conditions elements crucial to metabolism could form. Pyruvic acid is essential for extant intermediary metabolism. Using a high temperature and high pressure, 250 degrees Celsius and 200 MPa, the experiment showed that pyruvic acid forms from formic...