Figure 1
From: Evolution of variation in presence and absence of genes in bacterial pathways
Structure of the model. Structure of the model for the case n = 5. Variables x i in the circles represent the proportion of the population carrying i genes of the 5-gene pathway in a genome. Horizontal arrows to the left indicate the effects of deletions. Curved arrows to the right show the effect of horizontal transfer. Fitnesses are depicted by arrows below populations.