Fig. 2.

Gene losses and gains across vertebrate species tree. Data are shown for 17 vertebrate species, three teleost (red), an amphibian (green), six reptilians (including birds) (black, blue, and orange), and five mammals (yellow). The numbers of gene family gains (+) and losses (−) are given to the right of the taxa (p-value < 0.05) compared to the taxon’s last common ancestor. The rate of gene birth and death for clades derived from the most recent common ancestor (MRCA) for Gallianseriformes is 0.0016 (per gene per million years)