How a single-celled organism almost wiped out life on Earth - Anusuya Willis
View full lesson: http://ed.ted.com/lessons/how-a-single-celled-organism-almost-wiped-out-life-on-earth-anusuya-willis There's an organism that changed the world. It caused the first mass...
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There's an organism that changed the world. It caused both the first mass extinction in Earth's history and also paved the way for complex life. How? By sending the first free oxygen molecules into our atmosphere, and they did all this as single-celled life forms. They're cyanobacteria, and the story of these simple organisms that don't even have nuclei or any other organelles is a pivotal chapter in the story of life on Earth. Earth's atmosphere wasn't always the oxygen-rich mixture we breathe today. 3.5 billion years ago, the atmosphere was mostly nitrogen, carbon dioxide, and methane. Almost all oxygen was locked up in molecules like water, not floating around in the air. The oceans were populated by anaerobic microbes. ...
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There's an organism that changed the world. It caused both the first mass extinction in Earth's history and also paved the way for complex life. How? By sending the first free oxygen molecules into our atmosphere, and they did all this as single-celled life forms. They're cyanobacteria, and the story of these simple organisms that don't even have nuclei or any other organelles is a pivotal chapter in the story of life on Earth. Earth's atmosphere wasn't always the oxygen-rich mixture we breathe today. 3.5 billion years ago, the atmosphere was mostly nitrogen, carbon dioxide, and methane. Almost all oxygen was locked up in molecules like water, not floating around in the air. The oceans were populated by anaerobic microbes. ...
