Answer:
Homologous structures are similar in structure but differ in function and are inherited from a common ancestor. Vestigial structures, on the other hand, are remnants of structures that were functional in ancestral species but are no longer needed in the current species.
Step-by-step explanation:
Homologous structures are anatomical features that are similar in structure but differ in function. They are inherited from a common ancestor but may have evolved to serve different purposes in different species. For example, the forelimbs of mammals such as humans, bats, whales, and horses all have the same basic structure, with a humerus, radius, ulna, carpals, metacarpals, and phalanges, despite being adapted for different uses.
Vestigial structures, on the other hand, are anatomical features that have lost their original function over time. They are remnants of structures that were functional in ancestral species but are no longer needed in the current species. For example, the human appendix is a vestigial structure that was likely used for digesting cellulose in ancestral species but now has no known function in humans.