Figure 3.
Duplications detected in a search for fish nuclear receptor genes. The tree represents a simplified phylogeny of the fish in which we characterized new sequences, although more sequences were used when available. Branch lengths are arbitrary, and do not reflect evolutionary distance. Solid arrows indicate origin of duplications, as determined by phylogenetic analysis. Broken arrows indicate possible origin of duplications; we cannot exclude that these are more ancient, but we can exclude that they are more recent. All duplications indicated are specific to actinopterygian fish.
