In which vertebrate lineage has the studied gene evolved most rapidly?

The Zebrafish lineage has the studied gene that evolved most rapidly and its branch is the longest among the given lineage. Zebrafish is a tropical fresh water fish which is a popular aquirium fish commonly sold under the name zebra danio. It is important and widely used as a vertebrate model organism in research

The zebrafish lineage is the studied gene who evolved most rapidly as shown in its branch where it manifest to have the longest lineages. The changing branch lengths indicates that the gene has evolved at different rates in each lineages and the branch length is proportional to amount of the genetic variation in each linear.