‘bacteria-article’

An artist's impression of the earth's surface billions of years ago. The planet had almost zero oxygen in its atmosphere, but there was still life: microorganisms living in the globe-spanning ocean, long before today's continents were formed. (Image: National Geographic - The Story of Earth)

An artist’s impression of the earth’s surface billions of years ago. The planet had almost zero oxygen in its atmosphere, but there was still life: microorganisms living in the globe-spanning ocean, long before today’s continents were formed. (National Geographic – The Story of Earth)

An artist’s impression of the earth’s surface billions of years ago. The planet had almost zero oxygen in its atmosphere, but there was still life: microorganisms living in the globe-spanning ocean, long before today’s continents were formed. (Image: National Geographic – The Story of Earth)