why we breathe oxygen and not something like carbon dioxide or nitrogen?

393 views

why we breathe oxygen and not something like carbon dioxide or nitrogen?

In: 40

15 Answers

Anonymous 0 Comments

People have written whole books about this: https://www.amazon.com/Oxygen-molecule-Oxford-Landmark-Science/dp/0198784937

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 had on the evolution of life pose a riddle, which this book
sets out to answer. Oxygen is a toxic gas. Divers breathing pure oxygen at depth suffer from convulsions
and lung injury. Fruit flies raised at twice normal atmospheric levels of oxygen live half as long as their
siblings. Reactive forms of oxygen, known as free radicals, are thought to cause ageing in people.

You are viewing 1 out of 15 answers, click here to view all answers.