Code and data for: Are novel or locally adapted pathogens more devastating and why? : resolving opposing hypotheses

The naive host syndrome hypothesis suggests that pathogens are able to
easily invade and become deadly to novel hosts because of a lack of
co-evolutionary history, whereas the local adaptation hypothesis suggests
that pathogens are better able to invade local hosts because of their
co-evolutionary history, but rarely do studies on these two hypotheses
cite one another or acknowledge their ostensibly mixed messages. By
combining a continental-scale, factorial, common garden experiment with a
global-scale meta-analysis, each on the amphibian-chytrid fungus
host-pathogen system, we show that local host-pathogen interactions
typically resulted in higher host mortality, greater infection success,
and higher pathogen loads, but that there was substantial variation in
novel host-pathogen outcomes and thus moving pathogens around the planet
increases the likelihood of exposure to particularly virulent pathogen
strains and particularly deadly host-pathogen combination. Therefore, we
provide support for both the local adaptation and naïve host syndrome
hypotheses, highlight how the two hypotheses are complementary rather than
conflicting, and emphasize the need for greater integration of these
hypotheses and their associated semi-disparate literature.