Dwarf Galaxies of Tidal Origin: Relevant for Cosmology?

Evolutionary synthesis models for Tidal Dwarf Galaxies (TDGs) are presented that allow to have varying proportions of young stars formed in the merger-induced starburst and of stars from the merging spirals' disks. The specific metallicities as well as the gaseous emission of actively star forming TDGs are consistently accounted for. Comparison of models with observational data (e.g. Duc, this volume) gives information on the present evolutionary state and possible future luminosity evolution of TDGs. The redshift evolution of merger rates and of the gas content and metallicities of spiral galaxies are used to estimate the number of TDGs at various redshifts and to investigate their contribution to magnitude limited surveys