Super-spreaders: a historical review.

The term super-spreader is used for multiple, and sometimes even conflicting, purposes. The reasons for this can be traced back to its complex history. Forerunners of the super-spreader concept-in discussions of so-called dangerous carriers and in analyses of explosive outbreaks during the early 20th century-revolved primarily around gastrointestinal diseases, not respiratory ones. In 1957-58, the H2N2 influenza pandemic and Wells and Riley's studies on tuberculosis drew attention to both the viability of airborne transmission and the existence of significant heterogeneity in infectivity. The term super-spreader was coined in 1972, in relation to computer simulations of influenza epidemics. Initially, super-spreaders were simply an additional feature within stochastic models of epidemics, with little effect on an epidemic's eventual course. The term was later appropriated to explain why outbreaks of airborne diseases continued in vaccinated populations, defying the predictions of contact-transmission-based models. The content and meaning of the term continued to fluctuate, from the mathematical characterisation of sexually active people with gonorrhoea, through HIV carriers with highly infectious semen, to central nodes within a network. This Historical Review reconstructs the historical growth of the concept of super-spreading, and offers insight into its current, highly diversified use.

Kristine Bonnevie's theories on the genetics of fingerprints, and their application in Germany.

This paper offers a historical reconstruction of the efforts to geneticize fingerprints, focusing on the theories put forward by the Norwegian biologist Kristine Bonnevie. The criminological and colonial roots of the preoccupation with fingerprints led to the creation of huge catalogues of fingerprints, which later became the starting point of Bonnevie's analysis. Building on insights she gained from her studies on the inheritance of human pathologies, Bonnevie insisted that all ten fingers exhibited varying manifestations of a single, underlying genotypic design. In 1923-4, she identified several theoretical genes that presumably constituted this hypothetical genotypic finger; five years later she revised her theory in light of a series of embryological dissections she conducted. Her new theory was adopted by German jurists, doctors and racial-anthropologists who relied on it to determine legal questions of disputed paternity. The extensive application of Bonnevie's genetic theory also exposed its deficiencies, and by the late 1950s her model was abandoned. At the same time, one of the most important genetic variables that Bonnevie discovered (or, invented) entered mainline genetic theory, and is still being used to this very day. The paper examines these developments, highlighting the multiple and complex relations between scientific theory building, practical considerations related to the gathering and processing of data, and social, racial and gender biases that shaped the process of "Mendelization" of finger print patterns.

Mendel's use of mathematical modelling: ratios, predictions and the appeal to tradition.

The seventh section of Gregor Mendel's famous 1866 paper contained a peculiar mathematical model, which predicted the expected ratios between the number of constant and hybrid types, assuming self-pollination continued throughout further generations. This model was significant for Mendel's argumentation and was perceived as inseparable from his entire theory at the time. A close examination of this model reveals that it has several perplexing aspects which have not yet been systematically scrutinized. The paper analyzes those aspects, dispels some common misconceptions regarding the interpretation of the model, and re-evaluates the role of this model for Mendel himself. In light of the resulting analysis, Mendel's position between nineteenth-century hybridist tradition and twentieth-century population genetics is reassessed, and his sophisticated use of mathematics to legitimize his innovative theory is uncovered.