Terrawatch: oxygen feasts and famines kick-started complex life
by Kate Ravilious from Science | The Guardian on (#4GGPZ)
Examining isotopes in Cambrian rocks reveals 'boom and bust' cycles in levels of gas
Life on Earth got started more than 4bn years ago, but it was another 3.5bn years before evolution really started to take off. The turning point happened about 540m years ago and is known as the Cambrian explosion.
A plethora of complex creatures burst on to the scene, many of which were the precursors of the animal groups we see today. Now a new study reveals that oxygen was a crucial ingredient for this sudden flowering of life.
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