This is true of both branches of evolution, individual and phyletic.
The frogs in this phyletic line retained the moderate size of the prototype and did not develop additional dermal bone.
This phyletic line retained the larval characters and breeding call of the prototype.
All can be interpreted as embryonic survivals rather than as phyletic contractions.
The trend of phyletic development in the dipodomyines has been toward the saltatorial habit.
The Agalychnis phyletic line has one kind of specialization for an arboreal existence.
In nearly all phyletic or class descriptions the word "symmetry" occurs, and its exact meaning must be understood.
Variation along the phyletic lines is gradual and determinate, and appears to obey definite laws.
Even so, a considerable amount of parallelism is evident in the phyletic trends of the two genera.
Its structure does provide clues as to phyletic development that took place in the main lineage.