Evolution and Ancient Diseases: the Roles of Genes, Germs, and Transmission Modes

Abstract

Abstract Evolution through natural selection is the fundamental organizing principle of the life sciences. It explains not only how the diversity of life came to be but also provides a framework for understanding what is possible and what is not. Considering that the health sciences is largely a subset of the life sciences we can expect that principles of evolutionary biology will be able to provide some general guiding principles into any particular focus of study within the health sciences. Because the study of ancient infectious diseases involves time periods over which humans and especially pathogens can evolve in response to each other, an evolutionary perspective would seem especially appropriate. However, apart from the use of phylogenetic analyses, inquiry into ancient diseases has proceeded largely without reliance on evolutionary principles. Now that powerful techniques for analyzing the molecular makeup of humans and pathogens in ancient tissue are becoming available, it seems an especially appropriate time for incorporating evolutionary insights into decisions about what to look for and where to look. This chapter addresses two topics that are currently being developed in evolutionary medicine that also bear on the study of ancient diseases: the evolution of virulence and the scope of infectious causation.