This is an interesting chart because of all of the gaps, the unconnected lineages. Scientists have many hypotheses concerning how the different groups and families and cladograms are often drawn to show the most likely, or hypothesized, connection, but evidence is often inconclusive due to reasons stated before including the many species absent from the undiscovered fossil record. These gaps, the transience of our understanding regarding these relationships, does not diminish the value of the work done by the APG. Theirs is a truly epic task, 300,000 species and a great many thousands more extinct which have thus far remained unknown to us through fossil remains.