Fig. 3.

Adaptive divergence between biotypes of the pea aphid does not correlate with their genetic differentiation. Adaptive divergence is based on host-specialization tests. It represents the Euclidian distance between 2 biotypes from their performance (produced biomass in milligrams) on their 2 representative host plants (see Fig. 1). Errors bars represent standard deviations over Euclidian distances that were computed between any 2 laboratory lineages of these biotypes.