Figure 1.

A phylogenetic tree showing the vertebrate phylogenetic relationships and superimposed pufferfish gene-duplication events. (a) A generally accepted tree illustrating the relationships between several vertebrate species. The gray horizontal bar denotes the fish-specific genome-duplication event inferred from absolute dating of Takifugu paralogs. The broken line indicates the position of the duplicated copy of the Takifugu genome that originated between the divergence of gar and the bony tongues. (b) The bar chart shows the number of paralogous genes that could be dated through the construction of linearized trees. Modified from [8,9].