New Oxygen research; from rocks, higher earlier (Introduction)

by dhw, Sunday, August 28, 2016, 16:11 (3009 days ago) @ David Turell

QUOTE: The team's study identifies, for the first time, exactly how much oxygen was in Earth's atmosphere 813 million years ago -- 10.9 percent. This finding, they say, demonstrates that oxygenation on Earth occurred 300 million years earlier than previously concluded from indirect measurements.
"'Diversity of life emerges right around this time period," Benison said. (dhw's bold)-dhw: No it doesn't. It emerges 300 million years later.-QUOTE: "We used to think that to have diversity of life we needed specific things, including a certain amount of oxygen. (The findings) show that not as much oxygen is required for organisms to develop." -dhw: No they don't. We need to know the amount of oxygen during the Cambrian, and the article does not even mention that! 
I drew your attention to two articles that referred specifically to the Cambrian. Your response isAVID: From your article: "Imagine being able to test drops of actual Precambrian seawater to find out just how much oxygen the oceans contained at a given moment in the distant past. That's what Natalie Spear has done. Last year, this geologist and her team at Pennsylvania State University in State College discovered ancient seawater droplets in Australia. They were trapped in 830 million-year-old salt crystals. When saltwater evaporates, it leaves behind this mineral, called halite."
This is essentially the same salt methodology as my article! With a different result. If my article is correct, then the point remains that oxygen may not be the 
trigger.-The result is a difference of 10% compared to 10.9%. Your article confuses the time when diversity of life emerged, and does not tell us the amount of oxygen believed to have been present in the lead-up to the Cambrian (between 50% and 80% according to my article). Even the possibility that organisms can develop with less oxygen than originally thought does not preclude higher oxygen as the trigger for the Cambrian. It certainly doesn't remove “from consideration that the Cambrian explosion almost 300 million years later was triggered by oxygen”. However, this is all very minor. Even if an increase in oxygen did trigger the explosion, it still doesn't explain how organisms managed to respond with all their innovations. So we still have our mystery.