Discontinuous genomic coding and paradigm shifts in molecular biology and immunology: revolutions via "normal science".

The past 60 years have seen explosive changes in the fields of molecular biology and immunology which now affect clinical medicine as well as our knowledge of living systems. The succession of new discoveries and their transforming effects on intellectual paradigms in biology represent an interesting case to compare with Kuhn's dichotomy between "normal science" and "revolutionary science". Here, three conceptually disruptive discoveries are discussed: (1) the discovery and significance of messenger RNA (mRNA) splicing; (2) the discovery and significance of immunoglobulin gene somatic rearrangement; and (3) the discovery that mutational breaking and joining of DNA in immune cells is so evolutionarily important that this systemic function is conserved even when the particular molecules involved are dispensable. Despite their shocking nature for the paradigms of the time, all three discoveries emerged from normal science.