Epigenetic inheritance of resistance to exogenous nucleic acids via small interfering (si) RNA is well established in animal models. Rechavi et al. demonstrate epigenetic inheritance of a starvation-induced pattern of gene silencing caused by endogenous siRNAs and resulting in an increased longevity in the third generation progeny. Combined with recent findings in prokaryotes, these results suggest that Lamarckian-type inheritance of acquired traits is a major evolutionary phenomenon.