2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/15493Uncertainties in stellar nucleosynthesis and their impact on models of chemical evolution are discussed. Comparing the Type II supernova nucleosynthesis prescriptions from Woosley & Weaver (1995) and Thielemann, Nomoto, & Hashimoto (1996), it turns out that the latter predict higher Mg/Fe ratios that are more favorable in reproducing the observed abundance features of the Milky Way. Provided that chemical evolution models are calibrated on the solar neighborhood, they offer a powerful tool to constrain structure formation. In particular, galaxy formation models that yield star formation histories significantly longer than 1 Gyr fail to reproduce the super-solar Mg/Fe ratios observed in elliptical galaxies.6 pages, 2 figs., to appear in 'The chemical evolution of the Milky Way: stars vs clusters', F. Giovannelli & F. Matteucci, proceedings of the Vulcano Workshop, Sep. 1999Astrophysicstext