Is there anything you need help with for this problem? I need to clarify first before answering your question.
A - rostral and cranial are very similar but rostral are for head structures
HOPE I COULD HELP!!! C:
Answer:
Speciation occurs at terminal population groups
Explanation:
A ring species represents a group of organism that has moved beyond a geographic barrier to produce a ring shaped distribution. This population is contiguous and there exists no barrier to gene flow anywhere in the ring except at the terminal populations.
Speciation is demonstrated in the terminal population has become sympatric and it does not interbreed even if they are connected by chain of intergrading or interbreeding populations
The formation of the canyon provides a physical barrier that me lead to speciation between the two populations if interbreeding is prevented. The population to the west of the canyon will probably adapt to feeding on the berries on land, and might therefore evolve traits for a terrestrial, vegetarian existence. The turtles to the east of the canyon will evolve to take advantage of the river environment, and aquatic characteristics will be further emphasised.