Ingenious idea!!!
I wondered what would happen if I enforce Metaves and Coronaves (Fain and Houde, 2004). If I do, the following occurs (3 mpt's, 759 steps)- [...] `--+--+--+--Podicepedidae | | `--Phoenicopteridae | `--+--Eurypygidae | `--+--+--Opisthocomidae | | `--Phaethontidae | `--+--+--Pteroclidae | | `--Columbidae | `--+--Steatornithidae | `--Aegothelidae
`--+--+--Psittacidae | `--+--Coliidae | `--Musophagidae
Interesting. Intuitively pleasing. :-)
How about constraining traditional orders? That makes 5 mpt's of 744 steps.
[...]
`--+--+--Opisthocomidae
| `--+--Cuculidae
| `--Musophagidae
Hey, this is one of the traditional contents of Cuculiformes!
So, according to parsimony, the classic topology is only 24 more steps than
Mayr and Clarke's tree, though it is thought to be incorrect by most
ornithologists. Fain and Houde's new hypothesis is only 39 steps longer,
despite appearing to be starkingly novel. Livezey and Zusi's topology,
which seems like it should be the best morphology-based one, is a whopping
103 more steps.