Figure 1.
An abridged phylogeny of the vertebrate lineage. Labels denote taxa for which comparative analyses were performed. The approximate timing of key radiation events is shown to the left. Extinct lineages and some extant lineages (e.g., Ascidians, hagfish, coelacanth, lungfish) have been omitted for simplicity. Lancelets, lampreys, sharks, reptiles, and mammals are, respectively, represented by Branchiostoma floridae (Florida lancelet), Petromyzon marinus (sea lamprey), Callorhinchus milii (elephant shark), Gallus gallus (chicken), and Homo sapiens (human). (CZ) Cenozoic.
