2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/97740We have studied the population-density relation in very sparse environments, from poor clusters to isolated galaxies, and we find that early-type galaxies with a young stellar population are preferably found in the lowest density environments. We show a marginal indication that this effect is due to an enhancement of the stellar formation independent of the morphological segregation, but we failed to find any effect from the internal dynamics.2 pages, 2 figures, to appear in "Galaxy Dynamics: from the Early Universe to the Present", ASP Conf Series, ed. F. Combes, G. Mamon, V. Charmandaris Unmatched "Astrophysicstext