Un’inattesa corrispondenza tra matematica e biologia. L’epistolario di Vito Volterra e Umberto D’Ancona

The 1920s marked the birth of mathematical biology, namely the study of the dynamics of the interactions between heterospecific populations in the same ecosystem. The key figures of the new scientific discipline are the physicist and mathematician Vito Volterra (1860 – 1940) and the biologist Umberto d’Ancona (1896-1964), as well as the work they collaborated on. Volterra had already been active in the field of the humanities since 1901, when he published his Prolusion Sui tentativi di applicazione delle matematiche alle scienze biologiche e sociali (On the attempts to apply mathematics to the biological and social sciences). Volterra had since then approached the study of life phenomena as empirical data to be expressed formulaically through the creation of mathematical models. Said approach was indeed first described in the aforementioned prolusion. For his part, D’Ancona tackled the issue of marine population equilibrium through statistical observations acquired from fishing data. Said data allowed him to formulate a theory, which in turn became a law thanks to the mathematical models provided by Volterra. The law was later used by biologists and ecologists as a tool to predict population trends. The conceptual analysis of mathematical biology offered by Volterra is characterized by methodologies adapted from various subjects, such as rational mechanics, the study of preda- tor-prey interactions and gas kinetics, as a reference to Darwin’s work. The recent discovery of a large part of the correspondence between Volterra and D’Ancona adds a missing piece to the understanding of this topic spanning different disciplines.