Majority of mathematicians hail from just 24 scientific ‘families’

M ost of the world's mathematicians fall into just 24 scientific 'families' , one of which dates back to the fifteenth century. The insight comes from an analysis of the Mathematics Genealogy Project (MGP), which aims to connect all mathematicians, living and dead, into family trees on the basis of teacher–pupil lineages, in particular who an individual's doctoral adviser was 1. The analysis also uses the MGP — the most complete such project — to trace trends in the history of science, including the emergence of the United States as a scientific power in the 1920s and the rise to dominance of different mathematical subfields. " You can see how mathematics has evolved in time, " says Floriana Gargiulo, who studies networks dynamics at the University of Namur, Belgium, and who led the analysis. The MGP is hosted by North Dakota State University in Fargo and co-sponsored by the American Mathematical Society. Since the early 1990s, its organizers have mined information from university departments and from individuals who make submissions regarding themselves or people they know about. As of 25 August, the MGP contained 201,618 entries. As well as doctoral advisers and pupils of mathematicians, the MGP contains details such as the university that awarded the doctorate. Previously, researchers had used the MGP to reconstruct their own PhD-family trees, or to see how many 'descendants' a researcher has. Gargiulo's team wanted to make a comprehensive analysis of the entire database and divide it into distinct families, rather than just looking at how many descendants any one person has. After downloading the database, Gargiulo and her colleagues wrote machine-learning algorithms that cross-checked and complemented the MGP data with information from Wikipedia and from scientists' profiles in the Scopus bibliographic database. This revealed 84 distinct family trees with two-thirds of the world's mathematicians concentrated in just 24 of them. The high degree of clustering arises in part because the algorithms assigned each mathematician just one academic parent: when an individual had more than one adviser, they were assigned the one with the bigger network. But the phenomenon chimes with anecdotal reports from those who research their own mathematical ancestry, says MGP director Mitchel Keller, a mathematician at Washington and Lee University in Lexing-ton, Virginia. " Most of them run into Euler, or Gauss or some other big name, " he says. Although the MGP is still somewhat US-centric, the goal is for …