The field of prebiotic chemistry deals with experimental and theoretical approaches and scenarios toward an understanding of how biologically relevant molecules may have been formed and how they may have developed into protocellular systems, which eventually led to the origin of life. In this context, many progresses has been made, in recent years, in the field of the origin of nucleobases, nucleotides and oligonucleotides. We have shown that formamide (HCONH2), one of the simplest molecules grouping the four most common elements of the universe H, C, O and N, provides a chemical frame potentially affording all the monomeric components necessary for the formation of nucleic polymers. In the presence of the appropriate catalysts, and by moderate heating, formamide yields a complete set of nucleic bases, acyclonucleosides and favours both phosphorylations and transphosphorylations. We also observed that nucleoside phosphorylation and oligomerization may take place in water in nonenzymatic abiotic conditions. Both observations contribute to the understanding of the origin of informational polymers. Finally, we present experiments showing the non enzymatic ligation of oligo RNAs in water leading to the formation of RNA of biologically relevant length, ready to undergo to Darwinian selection.