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If all present forms of life descend from a common ancestor, the characteristics of such ancestor need to be searched among universally shared traits of extant organisms, non universal traits being the consequence of accumulated divergence through evolutionary time. One of the most remarkable of these universal traits is represented by the molecular aspects of genetic information processing, including the translational apparatus responsible for protein synthesis. Unfortunately, since biochemical pathways do not fossilize, we do not have access to the information on ancestral biological steps that led to present structures. As these previous biological steps are of primary importance for explaining the origin of life on earth, it seems that absence of evidence may hinder the finding of the ultimate causes of such origin. A similar problem arises in Cosmology when it comes to understand the origin of the matter in our known universe. The task might appear an impossible one since we would need to go back to the beginning of time. However, with the discovering of sky background radiation, different theoretical hypotheses about the origin and early evolution of our universe have become verifiable. Different theories are tested according to their predictions about the radiation background structure, for example, regarding the frequency content and the spatial distribution of the relic radiation produced at the time of the Big Bang. Again, we cannot reproduce experimentally the origin of the universe but this does not prevent us to obtain quantitative information about how the different proposed origin scenarios may
Publication date: 
30 Sep 2009

Diego Luis Gonzalez, Simone Giannerini, Rodolfo Rosa

Biblio References: 
Volume: 69 Issue: 2/3 Pages: 143-157