2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/18632Persistence phenomena in colonization processes could explain the negative results of SETI search preserving the possibility of a galactic civilization. However, persistence phenomena also indicates that search of technological civilizations in stars in the neighbourhood of Sun is a misdirected SETI strategy. This last conclusion is also suggested by a weaker form of the Fermi paradox. A simple model of a branching colonization which includes emergence, decay and branching of civilizations is proposed. The model could also be used in the context of ant nests diffusion.2 pages, no figures, v2 with corrected definition of branching ratioDisordered Systems and Neural NetworksStatistical Mechanicstext