Time: 3:30 pm
Location: ABB 102
Guest: Dr. David Deamer
Research Professor, Biomolecular Engineering
University of California, Santa Cruz CA
Title: Assembly of nucleic acids and protocells in hydrothermal fields
I will describe a series of steps involving polymerization of monomers such as amino acids and nucleotides, encapsulation of the polymers in membranous compartments to produce protocells followed by selection within protocell populations. Freshwater environments such as hot springs on volcanic land masses are conducive to the process, and the elevated temperature range provides activation energy required for polymerization. Multiple wet-dry cycles serve the essential role of concentrating potential reactants and providing chemical free energy to drive condensation reactions. Random sequence polymers are synthesized under these conditions, and if lipids are present the polymers are encapsulated to form vast numbers of protocells. Each of these steps has been tested and confirmed. Because protocells have different compositions, each protocell is a microscopic experiment and their populations are subject to selection by environmental stresses. Most are inert and their components are dispersed into the environment. However, a few will have compositions that increase their stability and may contain polymers having biologically relevant functions. Over time, these will begin to dominate the populations and become potential stepping stones leading to primitive forms of life.