Biologists are quietly rewriting what it means to be alive, and the human body has become one of their strangest frontiers. Inside our cells and microbiomes, researchers are uncovering entities that ...

Seven years ago, researchers showed that they could strip cells down to their barest fundamentals, creating a life form with the smallest genome that still allowed it to grow and divide in the lab.

Despite decades of progress, the origin of life remains one of the great unsolved problems in science. “The most basic features of biology, that organisms are made of cells, that they pass genetic ...