The giant dragonflies of ancient Earth with wingspans of up to 70 centimeters (28 inches) are generally attributed to higher oxygen atmospheric levels in the atmosphere in the past. New experiments in raising modern insects in various oxygen-enriched atmospheres have confirmed that dragonflies grow bigger with more oxygen, or hyperoxia.
I can hardly wait for more work to be done in this field. I expect that after many generations of insects being raised in a hyperoxic environment there might be some substantial differences between them and their low O2 brothers. Maybe they should try this on fruit flies due to they rapid reproductive rate. The stated goal should be a humming bird sized fruit fly within 20 years. Quite safe outside the lab due to the extra oxygen needed unless someone invents a tiny SCUBA system for them to wear… Please don’t tell DARPA about this one!
Raising giant insects to unravel ancient oxygen