A "sensitive" cell system. Its role in a new evolutionary paradigm.

The cell property of processing the environmental information is called sensitivity and referred to a "sensitive" cell system in which physical signals and specialized molecules work in relation to peculiar cell structures. It is suggested that, in addition to its role in cell behaviour, the sensitive system performs a basic role in morphogenesis in all cells. It interacts with the genetic system in gene expression and regulation directly or indirectly through epigenetic processes. Epigenetic inheritance, adaptive mutations and genetic assimilation allow environmental information to be embodied in new traits, thereby becoming relevant in evolution. This is consistent with an evolutionary mechanism with two alternate and recurrent phases: the first, epigenetic and Lamarckian at cell and organism levels and the second, selective and Darwinian, at population level.