What effect do control measures like chemical pesticides have on aphid evolution?
They act as intense artificial selection, accelerating evolutionary shifts toward tolerant morphs
Pesticides and biocontrol agents introduce an artificial, intense selective force into the aphid environment. If these control methods do not affect all color morphs equally—perhaps because a genetic trait linked to color also confers tolerance to the chemical—the treatment acts as a strong filter. For instance, if a pesticide kills 90% of the green population but only 50% of the yellow population, the subsequent generation will inevitably feature a higher proportion of yellow aphids. This immediate selection pressure rapidly alters the population structure, accelerating evolutionary change and demanding that pest management strategies explicitly account for the potential for immediate, measurable genetic shifts in the target populations.
