The concepts of biological specificity (of species, macromolecules, genes etc.) and genetic causality (in particular regarding heredity and development) played an important role in rendering biology a modern experimental science in the nineteenth century. Neglecting these concepts often led to stagnation in a field of study as, for example, in Spemann's embryology, which excluded genetic causality.
Mathematical models, which were widespread in experimental biology since its beginnings, differed, among other things, in the consideration of these principles. This paper presents the properties and epistemological basis of pertinent models, from Mendel's model of heredity in the 19th century to Eric Davidson's model of developmental gene regulatory networks in the 21st, and analyzes the extent to which the above principles explicitly or implicitly guided the modelling process. It claims that models that disregarded these principles, such as D'Arcy Thompson's models of biological form, failed to impact the direction of biological research in a lasting way, and that purely mathematical descriptions or simulations of biological phenomena, without incorporating a mechanistic idea and without experimental testing, fail to illuminate the biological causality.
