Insects first took to the skies about 350 million years ago, some 200 million years before birds first flapped their wings.

By the end of the Carboniferous period, 300 million years ago, some flying insects had become gigantic. Huge dragonfly-like insects called griffinflies had wingspans of 70cm – five times the size of the largest modern dragonflies.

These giant insects lived in a time when Earth’s atmosphere contained more oxygen than it does today: around 30%, compared with the modern 21%.

Because large flying insects lived in a time of high oxygen levels, scientists have proposed that they required these high external oxygen levels to power the rapid burn of energy during flight.

In new research published today in Nature, we studied the muscles of dozens of modern flying insects and made a surprising discovery: there is no reason the griffinfly could not survive in today’s atmosphere.

The structure of the insect flight respiratory system

Flying takes more energy than running or swimming, because a flapping........

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