Jillian Banfield never meant to reinvent the tree of life. But after two decades of studying microbial communities, the University of California, Berkeley, geomicrobiologist realized that previous iterations of the tree, which shows how organisms are genetically related, neglected vast swaths of life’s diversity. Half the world’s bacteria were missing, because they can’t be cultured in the lab. “They depend on other organisms for many basic requirements,” Banfield says. (She and her colleagues have identified them only by piecing together fragments of their DNA brought in from the wild.) Informed by more than 1,000 newly sequenced types of microbe, Banfield’s new tree reveals the diversity and long lineage of bacteria, which, along with eukaryotes and archaea, represent the three main domains of life. It also reveals how tightly interconnected many organisms are.
3 DOMAINS
The genetic tree of life is divided into three domains: Bacteria, Archaea and Eukaryotes. Bacteria and ...
