Modern Biology describes the cell as an autopoietic system, a ‘system that fabricates itself’. The concept of autopoiesis, or self-production, describes the ability of living systems to produce their own components and eventually to produce copies of themselves.
At a closer look, however, this is not always what takes place. In embryonic development, for example, the cells produce cells that are different from their progenitors. Most importantly, specific proteins did not exist before the origin of the genetic code, and the ancestral systems were producing descendants that were inevitably different from themselves. Autopoiesis was not present before the first cells, so it was not the mechanism that gave origin to them. Before the genetic code, the ancestral ribonucleoprotein system of the common ancestor was engaged in the process of evolving coding rules and was therefore a code generating system. After the genetic code, however, the situation changed dramatically. No other modification in coding rules was accepted and the system in question became a code conservation system.
Another part of the system, however, maintained the potential to evolve other coding rules and behaved as a new code generating, or code exploring system. In the early Eukarya, for example, the cells had a code conservation part for the genetic code, but also a code exploring part/ for the splicing code. The origin of the first cells, in short, was based on the ability of the ancestral systems to generate the rules of the genetic code, and the subsequent evolution of the cells was based on two complementary processes: one was the generation of new organic codes and the other was the conservation of the existing ones.
Taken together, these two processes are the two complementary sides of a biological phenomenon that has been referred to as ‘codepoiesi’. The ancestral systems that gave origin to the first cells, in conclusion, were not autopoietic systems but they had to be codepoietic systems. And all the other cells that came after them in evolution were not always engaged in autopoiesis but were inevitably engaged in codepoiesis. What is always and necessarily present in all living systems, in other words, is codepoiesis, not autopoiesis.