Epigenetics, the science of heritable but modifiable information, is now a well-accepted component of many research fields. Nevertheless, epigenetics has not yet found broad appreciation in one of the most exciting fields of biology: the comprehension of evolution. This is surprising, since the reason for the existence of this alternative information-transmitting system lies certainly in the evolutionary advantage it provides. Theoretical considerations support a model in which epigenetic mechanisms allow for increasing phenotypic variability and permit populations to explore the adaptive landscape without modifications of the genotype. The data presented here support the view that modulating the epigenotype of the human bloodfluke Schistosoma mansoni by treatment of larvae with histone deacetylase inhibitor leads indeed to an increase of phenotypic variability. It is therefore conceivable that environmentally induced changes in the epigenotype release new phenotypes on which selection can act and that this process is the first step in adaptive evolution.