More than 2 billion years ago, long before Earth's atmosphere contained oxygen, one hardy group of microbes may have already evolved to live with the gas, setting the stage for the rise of complex life.
In a new genetic survey of ocean mud and seawater, researchers found evidence that the closest known microbial cousins of plants and animals — a group known as Asgard archaea — carry the molecular gear to handle oxygen, and possibly even convert it into energy. Previously, many Asgards studied were associated with oxygen-poor areas.
