This is a really great example of genetic research! Of course, dragging in an unprovable but generally accepted claim that it reproduces an earlier stage in evolution always helps boost attention. \n\nAre we really supposed to believe that the split (which seems to have such little effect) happened "500 million years ago" -- during the Cambrian, when the first vertebrates appeared -- and also that nothing much else happened to the 2-4 new paralogs? \n\nAh yes, they were evolutionarily conserved due to their important function(s), perhaps. In other words, not much evolution happened in this case -- or perhaps evolution didn't have anything to do with it.