Oxygen in the Oceans

We have a paper just released telling us that a lack of oxygen in the oceans held back the beginnings of life, released today (see Physorg and Science Daily). Yesterday, at www.wired.com/wiredscience/2011/01/toxic-cambrian-oceans/ we had a story from Science that claimed a changing ocean environment was responsible for an early extinction event – between 490 and 520 million years ago. Marine animals, it says, were suffocated when oxygen levels dramatically fell. However, the researchers made the point that although there was evidence the Cambrian era waters became toxic what they are actually looking at is the aftermath of the event – 'we don't have the cause for why the oceans suddenly went anoxic'.