Data from: Biological and statistical processes jointly drive population aggregation: using host–parasite interactions to understand Taylor's power law

The macroecological pattern known as Taylor's power law (TPL)
represents the pervasive tendency of the variance in population density to
increase as a power function of the mean. Despite empirical illustrations
in systems ranging from viruses to vertebrates, the biological
significance of this relationship continues to be debated. Here we
combined collection of a unique dataset involving 11 987 amphibian hosts
and 332 684 trematode parasites with experimental measurements of core
epidemiological outcomes to explicitly test the contributions of
hypothesized biological processes in driving aggregation. After using
feasible set theory to account for mechanisms acting indirectly on
aggregation and statistical constraints inherent to the data, we detected
strongly consistent influences of host and parasite species identity over
7 years of sampling. Incorporation of field-based measurements of host
body size, its variance and spatial heterogeneity in host density
accounted for host identity effects, while experimental quantification of
infection competence (and especially virulence from the 20 most common
host–parasite combinations) revealed the role of species-by-environment
interactions. By uniting constraint-based theory, controlled experiments
and community-based field surveys, we illustrate the joint influences of
biological and statistical processes on parasite aggregation and emphasize
their importance for understanding population regulation and ecological
stability across a range of systems, both infectious and free-living.