Our species likes to think of "life" and evolution as a carbon-based phenomenon involving lots of oxygen. The idea is that photosynthesis came around with cyanobacteria a couple billion years ago, spewing out enough oxygen to eventually spark Earth's magical transformation into Oxygenland, producing the rise of large animals in the Cambrian period. Tah-dah! Oxygen inspires the planet to propagate life-as-we-know-it.
But how about... hydrogen? At the bottom of the Mediterranean sea, it was announced last week that zero-oxygen animals have been discovered living in an undersea lake of intensely salty brine. Instead of pleasant oxygen bubbles, hydrogen sulphide--toxic to us O2-breathing fancypants types--comes out of the black mud underneath. And that's where our new friends, so new the scientists haven't even named 'em yet, can be found frolicking, cavorting, reproducing, and generally acting suspiciously like the multi-celled animals they are.
The animals are tiny, under one millimeter, but their discovery is huge. We've known for years that single-celled, simple organisms like bacteria and viruses can survive without oxygen. This new creature? It has millions of cells and functions independently. Instead of mitochondria, it boasts hydrogenosomes, bypassing the need for oxygen. The discovery could point to serious evolution of complex fauna phenomena millions or billions of years before the oceans were oxygenated. If so, prepare for a major paradigm shift in how most folks view evolution.
Tip o' the sheriff's hat to Sunspot Dan for the pointer.