THE TRANSFORMATION OF MOLECULAR-BIOLOGY ON CONTACT WITH HIGHER ORGANISMS, 1960-1980 - FROM A MOLECULAR DESCRIPTION TO A MOLECULAR EXPLANATION

The convergence of developmental biology - embryology - and molecular biology was one of the major scientific events of the last decades of the twentieth century. The transformation of developmental biology by the concepts and methods of molecular biology has already been describ ed. Less has been told on the reciprocal transformation of molecular b iology on contact with higher organisms.The transformation of molecula r biology occurred at the end of a deep crisis which affected this dis cipline in the sixties and seventies and which led to a cruel criticis m of the preexisting models of gene regulation. Numerous new, sometime s heterodox, models were proposed to describe the level at which gene regulation took place and its underlying mechanisms. The crisis resolv ed itself at the beginning of the eighties with the rapid accumulation of results from genetic engineering techniques and, above all, a disp lacement of the descriptive level from the molecule to the cell. This displacement gave molecular biologists the 'explanandum' which had bee n cruelly lacking during their initial study of higher organisms. The new molecular cell biology is an interfield explanation of living phen omena, relating a description and an interpretation localized at diffe rent levels of organization.