What happened to the greenish warbler birds as they migrated from the southern portion of their range up around the Tibetan Plateau? a. They evolved separately as they moved north and became two separate species. b. The original species died off, but the ones that were able to adapt to a northern climate evolved into a new species. c. As a whole the species was able to adapt to a colder climate, but no significant changes occurred. d. They were unable to adapt and evolve to ensure their survival and became extinct. Please select the best answer from the choices provided A B C D

The correct answer is - option A. They evolved separately as they moved north and became two separate species

Explanation:

Greenish warbler is a leaf warbler present in many regions in the world and shows migration in winters in the Indian region. The main region of the migration is Tibetan Plateau.

They migrated from the southern part of these birds range and moved north and evolved separately from the main species and become two distinct species due to their geolocation and environment change.

glacial erosion, the picking up and movement of earth beneath a glacier, is also referred to as plucking. erosion and transportation of individual pieces of bedrock, especially large "joint block occur as a result of this glacial erosion. plucking is type of erosion in which rocks become frozen into the bottom and sides of the glacier.as the glacier moves downhill it 'plucks' the rocks frozen into the glacier from the ground.