Aromatic world

The relation between our minimal protocell assembly work and the classical origins of life questions may be expressed in the following manner (Ehrenfreund et al., 2006):

It is generally assumed that life emerged on Earth, was initially very simple, and was functionally similar to life as we know it today. Although it is notoriously difficult to define life, a molecular system can be considered alive if it turns resources into building blocks, grows, replicates, and evolves. Primitive life may have consisted of a compartmentalized genetic system coupled with an energy-harvesting mechanism. How prebiotic building blocks self-assemble and transform themselves into a minimal living system can be broken into two questions: (1) How can prebiotic building blocks form containers, metabolic networks, and informational polymers? (2) How can these three components cooperatively organize to form a protocell that satisfies the minimal requirements for a living system? The functional integration of these components is a difficult puzzle that requires cooperation among all the aspects of protocell assembly: starting material, reaction mechanisms, thermodynamics, and the integration of the inheritance, metabolism, and container functionalities. Protocells may have been self-assembled from components different from those used in modern biochemistry. We propose assemblies based on aromatic hydrocarbons may have been the most abundant flexible and stable organic materials on the primitive Earth and discuss their possible integration into a minimal life form. We further attempt to combine current knowledge of the composition of prebiotic organic material of extraterrestrial and terrestrial origin, and put these in the context of possible prebiotic scenarios. Finally we describe laboratory experiments that might help clarify the transition from nonliving to living matter using aromatic material. This proposed program presents an interdisciplinary approach to interface state of the art knowledge in astrochemistry, prebiotic chemistry, and artificial life research.

P. Ehrenfreund, S. Rasmussen, J. Cleaves, and L. Chen, Experimentally tracking the key steps in the origins of life: The Aromatic World, Astrobiology 6 (2006) 490
S. Colgate, S. Rasmussen, J. Solem, and K. Lackner, An astrophysical basis for a universal origin of life, Advances Complex Systems 6 (2003) 1