Tree of Life by Chris Bartley

The Tree of Life created by David M. Hillis, Derrick Zwickl, and Robin Gutell, University of Texas.

Description from their web site ( www.zo.utexas.edu/faculty/antisense/DownloadfilesToL.html  ): "This tree is from an analysis of small subunit rRNA sequences sampled from about 3,000 species from throughout the Tree of Life. The species were chosen based on their availability, but we attempted to include most of the major groups, sampled very roughly in proportion to the number of known species in each group (although many groups remain over- or under-represented). The number of species represented is approximately the square-root of the number of species thought to exist on Earth (i.e., three thousand out of an estimated nine million species), or about 0.18% of the 1.7 million species that have been formally described and named."

Disclaimer: I have no affiliation with the creators of this image, just an admirer of their work (and its subject!).