You're looking at an artistic representation of what is known as a Hillis plot — a visual snapshot of the evolutionary relationships connecting Earth's various life forms. Evolutionary biologists would call this a big, circular phylogenetic tree.
The Hillis Plot featured here was transposed onto a cross-sectional image of an English oak tree by artist Carol Ballenger, and is, in fact, the largest diagram of its kind, created by scientists David Hillis, Derrick Zwickl, and Robin Gutell at the University of Texas. Here's what you're seeing.
Pictured here is a close-up of the section of the plot that contains us, H. sapiens. An image of the entire plot is featured below, and the full-size graphic (which is big enough for you to zoom around on looking at individual species, and also large enough to be printed as a wall paper) can be found here.
According to Hillis and his colleagues, the tree was assembled based on the analysis of small subunit rRNA sequences sampled from about 3,000 species — sampled, say the researchers, roughly in proportion to the number of known species from each of the six main groups of cellular life: animals, plants, fungi, protists, bacteria and archaea.
The number of species represented is roughly 0.18% of the 1.7 million that have been formally described and named (out of an estimated 9 million).
[Spotted on The Science Center]
Top image via The Science Center
Close up of Hillis plot via
The Hillis plot art was first published in Science back in 2003.