ABSTRACT
This chapter describes the emergence of collective properties of organization independently of the details of the interactions between the components. It tackles the genotype/phenotype question by using an automata network approach and concerning ourselves with very general properties of living beings. The chapter discusses three examples: cellular differentiation, the origin of life, and the evolution of species. The genome, or genotype, is the genetic message contained in the DNA of the chromosomes. It is the genome which determines, partly as a function of external conditions, the phenotype of the organism, that is to say the set of its physical and chemical properties, as well as its biological functions, such as the arrangement and function of the organs, height and weight. The apparent paradox of cell differentiation is the following: "Since all cells contain the same genetic information, how can there exist cells of different types within a single multicellular organism?".
