Abstract

In recent decades the expression "molecular biology" has progressively disappeared from journals, and no longer designates new chairs or departments. This begs the question: does it mean that molecular biology is dead, and has been displaced by new emerging disciplines such as systems biology and synthetic biology? Maybe its reductionist approach to living phenomena has been substituted by one that is more holistic. The situation, undoubtedly, is far less simple. To appreciate better what has happened it is necessary to acknowledge the following: the intial project of molecular biologists was not a reductionist one, but an attempt to naturalize the phenomena of life by using the epistemological principles of physics as a model; and, it is necessary to distinguish the early stages of molecular biology, and the later aggregating process which gave it its present characteristics. Only one of these characteristics, the importance of the informational vision, has been seriously challenged in recent years. But it is obvious that the ambition of most early molecular biologists to discover simple rules and principles explaining all of biological facts has vanished. The pendulum has now moved toward the study of the diversity generated by a long evolutionary history