Kaplan Nursing Entrance Practice Exam

What type of evolution occurs when structures share a common function but do not come from a common ancestor?

1. Convergent evolution

2. Divergent evolution

3. Adaptive radiation

4. Coevolution

The correct answer is: Convergent evolution

Convergent evolution is the correct answer because it describes the process where organisms from different lineages develop similar traits or structures due to adapting to similar environments or ecological niches. This type of evolution results in analogous structures, which serve the same function but do not share a common evolutionary origin. An example of this is the wings of bats and the wings of insects. Both structures enable flight but evolved independently in vastly different groups of organisms. Divergent evolution refers to species that share a common ancestor but evolve different traits or functions, often due to adapting to different environments. Adaptive radiation relates to the rapid diversification of a species into multiple forms, particularly when they exploit different ecological niches. Coevolution involves two or more species that influence each other's evolution, often in a mutualistic or antagonistic relationship. Thus, these concepts do not apply to the scenario where structures have a common function but lack a common ancestral background.