Cyanobacteria Poem by Mark Sauer

The greatest of the 7 known mass extinctions on Earth, and the first, took place 3.5 billion years ago when Cyanobacteria, blue green algae, evolved a new metabolism that exhaled free oxygen. They covered the oceans and poisoned the existing biosphere, killing 99% of existing species and driving the remnant anaerobes underground.we know nothing of the cology they destroyed; soft bodied creatures leave no fossils. An entire alternate history was liquidated. This poem is loosely based on a Larry zniven scifi story called ' The Green Marauder' in which our predecessors had evolved intelligence and died in helpless despair, unable to defeat the poisonous pathogen that created our world by destroying theirs.