Figure 14.24 Costs of defenses against herbivores in tobacco plants. Researchers damaged tobacco plants to simulate the act of herbivory. They then prevented a chemical response in some individuals by applying plant hormones to the damaged area of the leaves. (a) Damaged plants treated with the plant hormone produce a lower amount of chemical defense than damaged plants not treated with the hormone. (b) Damaged plants treated with the plant hormone also experienced higher lifetime fitness, as measured by the mass of seeds produced. Error bars are standard errors.
Data from I. T. Baldwin et al., The reproductive consequences associated with inducible alkaloid responses in wild tobacco, Ecology 71 (1990): 252–262.