Final answer:
The apple maggot fly example demonstrates sympatric speciation, wherein two populations from the same ancestral species become reproductively isolated and diverge within the same geographic region. Option C is correct.
Step-by-step explanation:
The apple maggot fly, Rhagoletis pomonella, is an example of sympatric speciation. This speciation process occurred when a native population of flies that originally fed on hawthorn species began to use apple trees for mating and egg-laying following the introduction of apples into North America. This host switch resulted in reproductive isolation and the division of the original population of flies into two distinct populations based on host plant preference, not geographic barriers.
Sympatric speciation occurs without geographic separation, where new species evolve from a single ancestral species while inhabiting the same geographic region. Unlike allopatric speciation, which is driven by physical separation, sympatric speciation arises from factors such as genetic mutations, behavioral shifts, or preference for different ecological niches within the same environment.
Consequently, the apple maggot fly presents clear evidence of sympatric speciation, reinforcing the mechanisms through which species diversify.