Evolution of organisms is an ancient concept as one of the belief by Charles Darwin also tells that we human beings have evolved from the monkeys. That theory is based on the resemblance of different traits and function between two different individuals. When it is about the resemblance of different body structures of the organism, then it gives rise to the concept of homologous structure and analogous structure. The similarity of the body structure of different organisms on the basis of their common ancestry is called homologous structures, whereas the similarity of the body structure of different organisms belonging from different groups is called analogous structure.
What is Homologous Structure?
The homologous structures of a different organism are similar to each other with respect to their anatomy, morphology, embryology and genetics as they belong to the similar ancestor. Though these structures are having much of resemblance and hailing from similar ancestry, both these structures perform dissimilar functions that can be easily distinguished. For instance, the forelimbs of different organisms like whale, cat, horse, monkey and man are similar with respect to their anatomy. However, they are quite dissimilar when it is about the functions being performed by these forelimbs in different organisms. As per the belief the animals having homologous structures carry a common progenitor or belong to the same lineage, even with many similarities, these structures perform different functions. Taking a closer look at the homologous structures, the human arm, bird’s wings, seals’ flippers, and forelimb of horse have quite similar anatomy. On the other hand, these animals use these structures for different purposes as human uses hand to hold and grasp, the bird uses wings to fly, and seals use flippers to swim. Apart from belonging to the similar lineage or ancestry, the development of these homologous structures can also be seen in the related animals.
What is Analogous Structure?
The analogous structures of organisms are dissimilar in anatomy, morphology and the organism having these structures either belong to different groups, or they belong to the different ancestor. However, even with having many of the dissimilarities, these structures perform a similar type of functions. Even these analogous structures are different regarding that particular body structure and origin, and the development pattern is also dissimilar. For instance, the wing of the bat and that of the honey bee have different origin and are quite different to each other in terms of the anatomy of the structures. However, both of these structures perform quite a similar function as both are used for the flying purpose. This likeness in the structure are not due to the evolution of the organisms, or it is not among the similarly grouped organisms, it is in the body structures of organisms belonging to different groups and ancestry.
Homologous Structure vs. Analogous Structure
- The homologous structures of a different organism are similar to each other on their anatomy, morphology, embryology, and genetics, although these structures perform different functions. On the other hand, the analogous structures are different in terms of anatomy and morphology although they perform similar functions.
- The similarity of the body structure of different organisms on the basis of their common ancestry is called homologous structures, whereas the similarity of the body structure of different organisms belonging from different groups is called analogous structure.
- In homologous structures, origin and development of structures are quite similar, whereas in analogous structures origin and development of structures are