What term is used to refer to structures in organisms that have a similar origin or ancestry even though they may be very different in physical appearance?

The term used to refer to structures in organisms that have a similar origin or ancestry, despite differing in physical appearance, is "homologous structures." These structures arise from a common ancestor and exhibit similarities in their underlying anatomy, but they may have evolved different functions or appearances through the process of evolution. An example of homologous structures is the forelimbs of vertebrates, such as the wings of bats, the flippers of whales, and the arms of humans, all of which share a similar skeletal structure but serve different purposes in the respective organisms. The study of homologous structures is an important aspect of evolutionary biology, as it provides insights into the evolutionary relationships among species.