Stunning Archaean Stromatolites from Pilbara Craton

Endosymbiosis is the hypothesized event by which prokaryotes gave rise to the first eukaryotic cells sometime during Archaean time more than 2.6 billion years ago. Evidence of this paramount evolutionary occurrence is in the cells of all animals, specifically in the nucleic acid sequence of mitochondria, the organelles that are the cell's powerhouses; likewise the chloroplasts in plants. The sequences are similar to that of cyanobacteria, the builders of the great stromatolitic reefs that dominated much of Earth's geological history. When endosymbiotic events occurred is uncertain, but likely was during the Achaean Eon more than 2500 million years ago. This stromatolite dates to deep time in the Archaean, more than 2.7 billion years ago, and comes from the ancient Pilbara Craton of western Australia, one of only two Archaean-age crusts remaining on Earth. The array of colors are brought to stunning beauty by polishing to a mirror finish on one side.