a figure from the essay
Homeotic Genes and the Evolution of Anthropods and Chordates
by Sean B. Carroll
Figure 2 (from page 74 of Shaking the Tree: Readings from Nature in the History of Life edited by Henry Gee)
Hox genes and arthropod phylogeny. The array of Hox genes detected in arthropods and other invertebrates is displayed in comparison to the Drosophila Hox genes. By comparing annelids with arthropods and insects, it appears that most Hox genes pre-date the annelid/arthropod divergence, and all insect Hox genes pre-date the insect/crustacean divergence. Solid boxes represent confirmed Hox genes; stippled boxes are Hox genes that are too similar to another to be distinguished on the basis of available data; missing boxes represent the absence of information. Data are from surveys of the Hox genes of annelids,29 chelicerates59 and crustacea;28 the arthropod phylogeny on the left is from ref. 76. Other arthropod phylogenies are possible but do not affect the conclusions regarding Hox gene origins.
Back to the list of color illustrations.
About the book: Shaking the Tree: Readings from Nature in the History of Life edited by Henry Gee, published by the University of Chicago Press.