A single ancestral bird species colonizes an isolated oceanic archipelago featuring diverse ecological habitats ranging from dense rainforests to arid rocky volcanic slopes. Over time, descendant populations evolve distinct beak structures specialized for crushing hard seeds, probing tubular flowers, and snatching flying insects, eventually losing the ability to interbreed when their geographical ranges overlap. Which evolutionary process and reproductive isolating mechanism are primarily demonstrated in this scenario?
- Adaptive radiation resulting from ecological niche diversification, maintained by prezygotic behavioral or structural isolationAnswer
- BConvergent evolution driven by similar environmental pressures, maintained by postzygotic hybrid inviability
- CInheritance of environmentally acquired somatic traits, maintained by somatic gene modifications across generations
- DDiscontinuous variation caused by single-gene mutations, independent of natural selection and ecological niche availability
Answer
Adaptive radiation resulting from ecological niche diversification, maintained by prezygotic behavioral or structural isolation
The scenario describes adaptive radiation, where a single colonizing species rapidly diversifies to fill multiple vacant ecological niches. As populations specialize morphologically (such as beak shape), reproductive barriers evolve to prevent interbreeding; mechanisms that prevent mating or fertilization are prezygotic isolating mechanisms.
Step-by-Step Solution
Key Concept
Adaptive Radiation and Mechanisms of Speciation
Estimated Time:1m 15s