Final answer:
The Correct answer is option 1. wing of a bird and the arm of a human are homologous structures which exemplify divergent evolution, stemming from a common ancestor but having evolved for different functions.
Step-by-step explanation:
The wing of a bird and the arm of a human are examples of homologous structures, which indicate divergent evolution. These structures are derived from a common ancestor, but have evolved to perform different functions in different species. The concept of homologous structures is significant in the study of evolutionary biology, as it illustrates how different species can develop distinct adaptations for various environments or behaviors while maintaining a fundamental structural similarity.
Homologous structures are not to be confused with analogous structures, which are the result of convergent evolution. In convergent evolution, different species evolve similar traits independently of each other, often because they live in similar environments or face similar challenges. In contrast, vestigial structures are parts of an organism that have lost all or most of their original function in the course of evolution. Allopatric speciation refers to the formation of new species in populations that are geographically isolated from one another.
When discussing the topic of evolutionary biology, it is important to correctly identify these terms and understand their implications in the study of life's history. Therefore, the correct answer to the student's question is divergent evolution.