Resumen de Ocean oddity tells us about early life
Structures called stromatolites formed billions of years ago are one of the best records of early life. We assumed they were created by microbes that make food from sunlight. But the discovery of a modern stromatolite that formed in dark water in the deep Arabian Sea calls that into question. The researchers now have an idea how it might have formed without light and oxygen. They suggest that microorganisms use sulphates in the water to oxidize methane seeping out of the sea floor. This "chemosynthesis" produces sulphides. If these are then oxidized using nitrates in the water, the water will become more alkaline--triggering the precipitation of thin layers of calcium carbonate, helping to build the stromatolite
