Ancient Complexity

Northwestern Australia provides us with a glimpse of how life on Earth may have appeared more than two billion years ago. Our most ancient fossil record of complex biotic communities are layered structures known as stromatolites.

The Pilbara region, several hours north of Perth, contains massive outcrops of fossil stromatolites. These fossils are the remnants of ancient microbial communities that may have been dominant life form on the early Earth. The outcrop shown in this image towers 20 to 30 meters above the landscape.

The fossil record left behind can be quite well preserved, complex, and intricate such as the "Micky Mouse" figure below.

A few minutes away by small plane, Shark Bay is home to one of the most massive clusters of living stromatolites in existence. In this image taken from an altitude of approximately 200 meters, the dark brown curvilinear forms in the water are stromatolite colonies.

The shoreline view of these extraordinary colonies gives us an idea of what the shores of Earth may have looked like two billion years ago.

Underwater, the expected smooth nose-cone shape of the structures has been modified, sculpted, by local tides.

These fossil records of microbial community life can be distinguished from abiotic layered geological formations using computerized tomography for non-destructive creation of 3D maps, and then analyzing the morphology of the layers using complexity theory.