An example of a homologous structure is...

In the context of anatomy and evolutionary biology, homologous structures are anatomical features that share a common ancestry, even though they may serve different functions in the organisms that possess them. The example of a cat's forelimb and the pectoral fin of a dolphin demonstrates this concept effectively.

Both structures derive from a similar skeletal framework, reflecting their descent from a common vertebrate ancestor. Despite the differences in their shapes and functions—cats use their forelimbs for walking and manipulating objects, while dolphins use their pectoral fins for swimming—they structurally indicate evolutionary relationships. This distinction aligns with the scientific understanding that homologous structures arise due to divergent evolution, wherein species adapt to different environments and modes of life while retaining underlying anatomical similarities.