New Paper from the Antonovics Lab

This research was part of an NIH funded project on the evolution of transmission mode, and was carried out by Dr.Caroline Amoroso, as post-doc in Dr. Antonovics’ lab. The study was started last year, well before the Covid pandemic, but establishes a theoretical framework for modeling the effectiveness and costs of social distancing in humans during epidemics.

Studies of resistance evolution in disease epidemiology have assumed resistance evolves by physiological mechanisms that prevent pathogen invasion. However, many animals, just like humans, exhibit behaviors that reduce the probability of transmission by avoiding contact with diseased individuals. This theoretical study investigated how evolutionary processes are likely to differ between behavioral and physiological resistance. The major difference is that general avoidance (equivalent to social distancing in humans) is likely to be much less effective and evolve more slowly than specific recognition and avoidance of diseased individuals. The outcomes also depend on whether avoiding other individuals has a fixed physiological cost or if it is the result of losing the benefits of the social interaction itself.

Figure. (LEFT) Under specific avoidance, healthy individuals can recognize diseased individuals and avoid them. At high levels of avoidance, their spread extirpates the disease (red line goes to zero) while preserving social structure (blue line). (RIGHT) Under general avoidance, by avoiding social contacts reardless of disease status ("social distancing") reductions in the proportion of infected individuals (red line) only occur at the highest levels of avoidance, resulting in a deterioration of the social structure (blue line).

Amoroso, C., and Antonovics, J. 2020. Evolution of behavioral resistance in host-pathogen systems. Biology Letters 16: 20200508.