Figure 4

Lineage-specific lists of PRs: The number of species-specific PRs relative to other species. PRs specific relative to other species were obtained by comparison of Ks between the PR and its parent and the Ks between the parent (Ks _{PR_parent} ) and the ortholog of the parent in the other species (Ks _{parent_ortholog} ). PRs with Ks _{PR_parent} <Ks _{parent_ortholog} were defined as specific PRs relative to the other species. Only PRs which amino acid identity to parents is more than 70% and have an ortholog in other species were subjected to this calculation. Orthology criteria used are 40% identity over 60% length overlap. 'Human-specific' and 'Chimp-specific' PRs are those formed since the species diverged from each other; similarly, for 'Mouse-specific' and 'Rat-specific' PRs. 'Other primate-specific' are any other PRs formed in human or chimp since divergence from dog (in bold typeface), or from cow (in italic typeface); similarly, for 'Other rodent-specific'.