How would a taxonomist decide to place a sea turtle into a paticular family

Its ancesters

Geographical Isolation is the mechanism that might have led to the appearance of the Hawaiian honeycreeper.

Geographical Isolation is the term used that refers to a population of animals, plants, or other organisms that are separated and unable to exchange genetic materials with other organism of the same species.

Geographical Isolation may be a result of coincidence or accident.

Here are some factors of Geographical Isolation:
1) Isolation by barriers 
2) Isolation by distance
3) Isolation after an Event
4) Isolation by separation