What are homologous structures?

Homologous structures are defined as anatomical features that have a similar origin but may serve different functions in different species. This similarity in structure indicates a shared ancestry among the organisms, meaning that despite the differences in function—such as a human arm, a bat wing, and a whale flipper—these structures evolved from a common ancestor. The variations in function arise due to adaptations to different environments or lifestyles, showcasing the concept of divergent evolution.

Identifying homologous structures helps in understanding evolutionary relationships among organisms. This contrasts with structures that are analogous, which may perform similar functions but do not share a common evolutionary origin. As such, homologous features reveal more about genetic and evolutionary links than mere functional similarities.