The relative geographical positions, within species (but more often genera
and families), of primitive and advanced phylogenetic features are good
indicators of the trends of migration.
Migrations past have traveled by a certain route.
Today when you consult a chart whereon you note
[Consult a chart, a trusty chart, whereon you note]
Sets of philogenetic traits joined at the hip,
That route can be determined with your fingertip.