Nitrogen Revolution: Study breathes new life into 2.3 billion year old ‘Great Oxidation Event’
Research – led by the University of St Andrews and published yesterday in the journal Nature – provides new insight into how life evolved alongside changes in the chemistry of Earth’s surface. These researchers examined geochemical records of Earth’s ‘Great Oxidation Event’ 2.3 billion years ago, and captured for the first time the response of the nitrogen cycle to this major transition in Earth’s surface environment.
|Research is providing fresh insights into the “Great Oxidation Event,” when oxygen first appeared |
in Earth’s atmosphere [Credit: Denis Tabler/Shutterstock]
Dr Zerkle explained: “The ‘Great Oxidation Event’ was arguably the most dramatic environmental change in Earth history. It was critical to the development of the hospitable environment that we inhabit today, as it was a prerequisite for the evolution of animals that universally require O2 to live.
|Algae making bubbles of O2 in a South African lake [Credit: © Aubrey Zerkle/University of St Andrews]|
The rock cores Dr Zerkle and her colleagues studied, from the National Core Library in Donkerhoek, South Africa, have recently been used to date the occurrence of the Great Oxidation Event, and offer key insights about how this event affected the availability of nitrogen. Nitrogen is an essential element in all living organisms, required for the formation of proteins, amino acids, DNA and RNA. As a key “nutrient”, nitrogen therefore controls global primary productivity, which in turn regulates climate, weathering, and the amount of oxygen at Earth’s surface.
|Outcrop from the Duitschland Formation, which underlies the Rooihoogte and|
Timeball Hill formations in the Eastern Transvaal basin, South Africa
[Credit: © Aubrey Zerkle/University of St Andrews]
She explained: “Our data shows the first occurrence of widespread nitrate, which could have stimulated the rapid diversification of complex organisms, hot on the heels of global oxygenation. The building blocks were apparently in place, the question that remains is why eukaryotic evolution was seemingly stalled for another billion or more years.”
Source: University of St Andrews [February 08, 2017]