http://www.sciencemag.org/news/2020/06/pools-mexican-desert-are-window-earth-s-early-life > Azure pools rich in magnesium and calcium carbonate but low in phosphorus provide an ideal habitat for ancient bacterial reefs at Cuatro Ciénegas, in the Chihuahuan Desert of Mexico. > Valeria Souza Saldívar never planned to devote her life to a remote and ancient oasis more than 1000 kilometers north of her laboratory in Mexico City. But a call in early 1999 changed that.