Light element evolution resulting from WMAP data

The recent determination of the baryon-to-photon ratio from Wilkinson Microwave Anisotropy Probe (WMAP) data by Spergel et al. allows one to fix, with unprecedented precision, the primordial abundances of the light elements D, He-3, He-4 and Li-7 in the framework of the standard model of big bang nucleosynthesis. We adopt these primordial abundances and discuss the implications for Galactic chemical evolution, stellar evolution and nucleosynthesis of the light elements. The model predictions on D, He-3 and He-4 are in excellent agreement with the available data, while a significant depletion of Li-7 in low-metallicity stars is required to reproduce the Spite plateau.