If you are alive on Earth, there's a good chance you're microscopic. "From a diversity perspective, 95%" of life on this planet is smaller than the eye can see, Laura Hug, an environmental microbiologist at the University of Waterloo in Canada says. And that collection of microorganisms just got a lot more complex.  are reported in a paper published Monday in the journal Nature Microbiology, authored by Dr. Hug, as a postdoctoral fellow at the University of California, Berkeley, along with colleagues there. These additions greatly expand the tree of life, a model used by biologists to describe the phylogenetic relationships between all known species, living and extinct. "The tree itself is a