But smaller species, whose respiratory needs are fully satisfied in low oxygen, are not expected to breathe any faster. Back in the lab, Harrison also tests his ideas by looking at size variation within a single species. He uses grasshoppers for this work. A dragonfly begins life as worm-like larva. It then undergoes a metamorphosis into a flying adult.
Grasshoppers skip the larva stage.
Baby grasshoppers are born looking like miniature versions of their parents. As they age and grow, they shed their confining outer skeletons and replace them with roomier new ones. This process, called molting, happens several times before the grasshopper reaches adult size. Each time a grasshopper molts to a larger size, its oxygen requirements increase. Harrison is now planning experiments to see if the minimal amount of oxygen required for hopping increases at progressively larger stages.