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Showing posts from November, 2017

Correlation Between the Great Oxidation Event and a Snowball Earth

Quote: “Both Snowball Earth periods had extreme impacts on the development of life. It helps us understand the evolution of Earth and Earth’s atmosphere, and evolution of life, for that matter.” -Kevin Chamberlain, a UW research professor in the Department of Geology and Geophysics. Initial Claim: Professor Chamberlain’s extensive research about the rise of life’s correlation to a Snowball Earth shows evidence that the Great Oxidation Event occurred approximately 2.5bya. His research talks about when the Earth’s climate swung where the polar ice caps extended to the equator and the Earth was a complete snowball, and the atmosphere was separated from the hydrosphere. His paper then states that when the Snowball Earth melted and turned slush, Great Oxygenation Event occurred, giving way to aerobic life. Background: The first Snowball earth period occurred 2.3bya, where, at that time, the earth’s atmosphere was mostly made up of greenhouse gasses such as methane and carbon dioxid

Post #3

The Great Oxidation Event occurred as a result of cyanobacteria, pumping out unwanted oxygen, which in turn, transformed Earth's atmosphere. But while this explains how it the GOE happened, it doesn't explain why, and it doesn't really explain when it happened. The issue is that cyanobacteria seem to have been around long before the GOE.         "They're probably among the first organisms we have on this planet," says Bettina Schirrmeister of the University of Bristol in the UK. We can be confident that there were cyanobacteria by 2.9 billion years ago, because there is evidence of isolated "oxygen oases" at that time. They might date as far back as 3.5 billion years, but it's hard to tell because the fossil record is so patchy. That means the cyanobacteria were busy pumping out oxygen for at least half a billion years before oxygen started appearing in the air. That doesn't make a lot of sense. One explanation is that there were a lot of c