Fig. 4

Graphical representation of SEM. Solid, single-headed arrows indicate the direction of paths and the weight of each arrow is proportional to the path coefficient (r) from the predictor to the variable and the percentage of variation in the variable that is explained by each predictor. Positive effects (green arrows) indicate that the FVB allele increases the trait; negative effects (red arrows) indicate that the FVB allele decreases the trait. Double-headed, blue arrows represent covariate pathways detected in the structural model of microbial features and measures of diversity