DOI: 10.5061/dryad.c866t1gfm
title: Data from: Multispecies interactions and the community context of the evolution of virulence

description: Pairwise host-parasite relationships are typically embedded in broader
 networks of ecological interactions, which have the potential to shape
 parasite evolutionary trajectories. Understanding this "community
 context" of pathogen evolution is vital for wildlife, agricultural,
 and human systems alike, as pathogens typically infect multiple hosts –
 and these hosts may have independent ecological relationships. Here we
 introduce an eco-evolutionary model examining ecological feedbacks across
 a range of host-host interactions. Specifically, we analyze a model of the
 evolution of virulence of a parasite infecting two hosts exhibiting
 competitive, mutualistic, or exploitative relationships. We first find
 that parasite specialism is necessary for inter-host interactions to
 impact parasite evolution. Furthermore, we find generally that increasing
 competition between hosts leads to higher shared parasite virulence, while
 increasing mutualism leads to lower virulence. In exploitative host-host
 interactions, the particular form of parasite specialization is critical –
 for instance, specialization in terms of onward transmission, host
 tolerance, or intra-host pathogen growth rate lead to distinct
 evolutionary outcomes under the same host-host interactions. Our work
 provides testable hypotheses for multi-host disease systems, predicts how
 changing interaction networks may impact virulence evolution, and broadly
 demonstrates the importance of looking beyond pairwise relationships to
 understand evolution in realistic community contexts.
description: # MultihostParasite
 [https://doi.org/10.5061/dryad.c866t1gfm](https://doi.org/10.5061/dryad.c866t1gfm) Scripts and data files accompanying the manuscript "Multispecies interactions and the community context of the evolution of virulence". Outputs from simulations are found in (multihost_virulencedata.xlsx, see below for further detail). MATLAB Scripts in the Simulations folder can be used to generate the data in Figures 3-6 in the main text and in all Supplemental figures. R Scripts in the Figures folder produce the figures themselves. ### **Descriptions** ###### multihost\_virulencedata Sheet 1: Absolute ES Virulence * This sheet contains numerically-determined evolutionarily stable (ES) virulence values from MATLAB simulations, grouped into four columns for the four classes of host-host interactions (classes labeled with gold cell headers above each column).  * Each column contains four matrices of ES virulence values, one for each mechanism of parasite specialization (mechanism labeled at the top left corner of each matrix). * Entries in each matrix denote the ES virulence for a particular combination of host-host interaction and strength of parasite specialization. Blue cells (rows) denote the impact of Host 2 (non-preferred host) on Host 1 (preferred host). Green cells (columns) denote strength of parasite specialization.  * For nonreciprocal, asymmetric and reciprocal, asymmetric host-host interactions, the rightmost column alongside each Case matrix denotes the impact of Host 1 (preferred host) on Host 2 (non-preferred host) (parameter r_21).  Sheet 2: Relative ES Virulence * Normalizes the data from Sheet 1 for symmetric and asymmetric, reciprocal host interactions and symmetric, non-reciprocal host interactions. Data is normalized relative to the highest absolute ES virulence within each Case (1-4)  of parasite specialization.  * The same colored cells are used to denote degree of parasite specialization and type of host-host interaction as in Sheet 1.  ### **Code and Software** MATLAB and R are required to run the code provided. The scripts were created with MATLAB version R2023a and R version 4.3.1.