Galactic abundances are neither constant in time nor do they evolve in a simple fashion, e.g., by an enrichment of heavy elements in constant relative proportions. Instead, their evolution in space and time reflects the history of star formation and the lifetimes of the diverse contributing stellar objects. Stellar winds from intermediate and massive stars, as well as supernovae of type Ia and type II/Ib/Ic are the main contributors to nucleosynthesis in galaxies. Despite many efforts, a full and self-consistent understanding of supernova explosion mechanisms is not existing, yet. However, they leave fingerprints, seen either in spectra, lightcurves, radioactivities/decay gamma-rays or in galactic evolution. The aim of the present paper is to highlight how model uncertainties can be constrained from abundance observations.