How does comparative anatomy support the theory of evolution?

Comparative anatomy supports the theory of evolution primarily through the demonstration of evolutionary history via homologous structures. Homologous structures are anatomical features that share a common ancestry but may serve different functions across various species. For example, the forelimbs of mammals, birds, and reptiles exhibit similar bone structures, indicating that these species evolved from a common ancestor. This similarity in structure, despite variations in functionality—such as a human arm, a whale's flipper, and a bat's wing—provides compelling evidence of how evolutionary processes can lead to diversification in form and function while retaining underlying anatomical traits from a shared lineage.

By analyzing such homologous structures, scientists can trace evolutionary lineages and better understand the relationships among different species, which is a core principle in the study of evolution. This comparative approach allows researchers to infer patterns of descent, examine the mechanisms of natural selection, and explore the adaptive changes that occur over time. Therefore, the presence of homologous structures serves as a significant testament to the shared evolutionary heritage of life on Earth.