Changes in temperature alter susceptibility to a virus following a host shift

Katherine E. Roberts; Jarrod D. Hadfield; Manmohan D. Sharma; Ben Longdon

The random effects and the residuals are assumed to be multivariate normal with a 293 zero mean and a covariance structure Vp ⊗ A for the phylogenetic affects and Ve ⊗ 294 I for the residuals. A is the phylogenetic relatedness matrix, I is an identity matrix 295 and the V are 3×3 (co)variance matrices describing the (co)variances between viral 296 . CC-BY 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/358564 doi: bioRxiv preprint 13 titre at different temperatures. The phylogenetic covariance matrix, Vp, describes 297 the inter-specific variances in each trait and the inter-specific covariances between 298 them. The residual covariance matrix, Ve, describes the within-species variance that 299 can be both due to real within-species effects and measurement or experimental 300 errors. The off-diagonal elements of Ve (the covariances) are not estimable because 301 no vial has been subject to multiple temperatures and so were set to zero. We 302 excluded D. pseudoobscura from the full model as data for BMR was not collected, 303 but included it in models that did not include any fixed effects, which gave 304 equivalent results. The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/358564 doi: bioRxiv preprint these models were also run with wing as a proxy for body size as this is known to 322 influence thermal measures [51] . We observed significant levels of measurement 323 error in the metabolic rate data; this was partially caused by respiratory chamber 324 order during the assay. We corrected for this in two different ways. First, we fitted 325 a linear model to the data to control for the effect of respiratory chamber number 326 and then used this corrected data in all further models. We also used a 327