Science

A Brain Disease With No Identifiable Cause For much of the twentieth century, a cluster of fatal brain diseases defied every known rule of infection. They destroyed nervous tissue, left brains riddled with holes visible under a microscope, and spread between animals and humans — yet no bacterium, no fungus, and no virus could be…

A Fossil Half a Billion Years in the Making In the mudstone south of Kunming, in China’s Yunnan Province, researchers uncovered something that forced a serious rethink of early animal evolution. The fossil — now named Daihua sanqiong — is 518 million years old and belongs to a creature unlike anything alive today. It has…