Oxygen has had extraordinary effects on life.
Three hundred million years ago, in Carboniferous times, dragonflies grew as big as seagulls, with wingspans of
nearly a metre. Researchers claim they could have flown only if the air had contained more oxygen than today -
probably as much as 35 per cent. Giant spiders, tree-ferns, marine rock formations and fossil charcoals
all tell the same story. High oxygen levels may also explain the global firestorm that contributed to the
demise of the dinosaurs after the asteroid impact.
The strange and profound effects that oxygen has...