Billions of years ago, long before oxygen was readily available, the notorious poison arsenic could have been the compound that breathed new life into our planet. In Chile’s Atacama Desert, in a place called Laguna La Brava, scientists have been studying a purple ribbon of photosynthetic microbes living in a hypersaline lake that’s permanently free of oxygen.
Despite being super-salty and oxygen-free, La Brava lagoon in the Atacama Desert is host to a peculiar type of microbes
“I have been working with microbial mats for about 35 years or so,” says geoscientist Pieter Visscher from the University of Connecticut. “This is the only system on Earth where I could find a microbial mat that worked absolutely in the absence of oxygen.”