Answer: A. Evolutionary mechanisms work the two subgroups independently.
Explanation:
Speciation can be defined as the process by which new species develop from the pre-existing species. It occurs when the members of the same species get separated. The separated members become reproductively isolated and diverge.
The speciation of two separated members will take place individually due to the development of new traits according to the need of new habitat and other survival conditions. Thus evolutionary mechanism will work independently for the two subgroups.
