We studied the evolution of the Fundamental Plane in B– and g–bands, for two samples of early–type galaxies at 0.2 < z < 0.35 and 0.35 < z < 1.2. We found a difference in the intercept that can be interpreted as galaxies at < z > ~0.7 being 0.68 and 0.52 mag brighter in the B– and g–band respectively, than their local counterparts. From the study of the Kormendy relation, we found the existence of a population of very bright (−21.5 > Mg > −22.5) and compact (Re < 2 kpc) galaxies of which only a small fraction of 0.4% exists at z = 0, and that would be responsible for the apparent evolution in the Kormendy relation (Fernández Lorenzo et al. 2011). These compact objects would have evolved mainly in size by the action of “dry” minor mergers.
We checked the effect of these bright and compact objects in the FP by comparing the galaxies with −21.5 > Mg > −22.5 of our high–redshift sample and the SDSS early–type galaxies of Bernardi et al. (2003) in Fig. 1. The previous evolution found in the FP seems to be caused mainly by these galaxies, which have virtually disappeared at z = 0.