Chemical Elements Abundance in the Universe and the Origin of Life
  Element synthesis which started with p-p chain has resulted in several specific characteristics including lack of any stable isotope having atomic masses 5 or 8. The carbon to oxygen ratio is fixed early by the chain of coincidences. These, remarkably fine-tuned, conditions are responsible for our own existence and indeed the existence of any carbon based life in the Universe. Chemical evolution of galaxies reflects in the changes of chemical composition of stars, interstellar gas and dust. The evolution of chemical element abundances in a galaxy provides a clock for galactic aging. On the other hand, the living matter on the planet Earth needs only some elements for its existence. Compared with element requirements of living matter a hypothesis is put forward, by accepting the Anthropic Principle, which says: life as we know, (H-C-N-O) based, relying on the number of bulk and trace elements originated when two element abundance curves, living matter and galactic, coincided. This coincidence occurring at particular redshift could indicates the phase of the Universe when the life originated. It is proposed to look into redshift region z = 0.5 to 2.5 (approximately t = -5.2x10E9 to -11.3x10E9 years) where many galaxies have been observed and to use these data to study the evolution of metallicity with respect to the other properties of galaxies in order to determine the time when universal element abundance curve coincided with the element abundance curve of LUCA. The characteristic properties of the latter have been transmitted by the genetic code while the universe element abundance curve changed as the galaxies aged. 
Vlado Valkovic
astro-ph.GA