Learn how scientific understanding of the tree of life has grown with the development of new gene-sequencing and data-processing techniques, in this article from NOVA Next. In the late 1970s, microbiologist Carl Woese developed a technique to identify microbes by comparing 16S rRNA genes, which code for the cell machinery used to make proteins. His research identified a new branch on the tree of life: archaea. However, some microbes have very different DNA and cannot be identified using 16S rRNA sequencing. These uncultured, unsequenced species were nicknamed "microbial dark matter"—unknown, but thought to make up a large portion of the tree of life. New technologies developed by Tanja Woyke of the Joint Genome Institute and Jill Banfield of the University of California, Berkeley, have helped to illuminate some of the "microbial dark matter” on Earth. This resource is part of the NOVA Next Collection.