A Little About Primitive Cyanobacteria

Stromatolites, formed by cyanobacteria (via wikimedia.org)

Stromatolites, formed by cyanobacteria (via wikimedia.org)

3.5 billion years old, that’s how old the oldest stromatolites are. Small, calcified structures, stromatolites were formed in shallow pools as cyanobacteria “trapped and bound sedimentary grains into layered domes;” that is, stromatolites are some of the oldest evidence of life on earth (they’re almost as old as the oldest rocks, which are slightly more ancient at 3.8 billion years old).

In the anoxic atmosphere of early earth (there was no oxygen), cyanobacteria played an important role in the changing environment by introducing more and more oxygen into the atmosphere; in the development of life on earth, early structures located inside the microbes used strategies that plants would later employ, such as photosynthesis. Today stromatolites are viewable in a few locations, Hamelin Pool in Shark Bay, Australia, is one of the most noted.