Evolution is one of the vital factors that contributed to the development of the physical appearance of humans and animals along with improvement in human civilization over millions of years. Homologous structure and analogous structure are two terms that study such changes in living organisms. These terms are different from each other yet share some kind of similarities.
Homologous vs Analogous Structures
The main difference between Homologous and Analogous Structures is that Homologous structure is a procedure that is used to examine similar traits in living organisms that are successors of the common ancestor. While the analogous structure is the study of identical traits in independent organisms that originated from a single source a very long time ago.
The term homologous belongs to biology that is described as having similarities in structure and shape because of shared ancestry. Homologous is commonly found between species and individuals in their unique structures. Homologous came to be known around the mid-1600s and was given the name. It is an important aspect or topic mentioned and studied in biology.
The features found in different living organisms that do not necessarily look identical in shape and structure but perform a similar function are considered to be part of the analogous structure. There are only parts included in analogous structure based on their similar function not because they share a common ancestor.
Comparison Table Between Homologous and Analogous Structures
| Parameters Of Comparison | Homologous Structures | Analogous Structures |
| Meaning | The homologous structure is a biological term that refers to the structures that originated from the same ancestors. | Analogous Structure is a biological term that is used to clarify the similarities in functions of different species. |
| Structure | Homologous structures are commonly similar in the anatomy of living organisms but different in functions. | Analogous Structures are different in the anatomy of living beings but very similar in functions they perform. |
| Origin | The homologous structure is generally known to have originated from the same ancestors that have evolved through the years. | Analogous Structure does not necessarily originate from the same ancestors since it is based on the similarities of functions. |
| Pattern | There is a common pattern of development found in Homologous structures since originating from the same forerunners. | There is not any common pattern of development found in the analogous structure, it is very irregular. |
| Type of evolution | The type of evolution that is responsible for the occurrence of Homologous structure is known as divergent evolution. | The type of evolution that is responsible for the occurrence of analogous structure is known as convergent evolution. |
What is Homologous Structure?
Homologous is the condition of having similarities between two things based on genes. Scientists have divided homologous into two divisions that are evolutionary or sometimes known as phylogenetic. The second category is called Homology, also known as iterative and serial.
In the first division, homologous studies are studied between several species and the second division provides information about ‘homologous’ found among individuals. The science used to study ‘homologous’ is designated as Homology. Homologous is a term that refers to the study of different structures and organisms and finding similarities within them.
It is associated with a physical feature that looks quite similar while it doesn’t matter if it performs different functions, it should be received from a common ancestor. To understand it better, there are many Homologous structures found in bats, cats, humans, and whales.
These structures can be found in any part of the body such as wings, arms, legs, etc. The only necessary fact required to link them from Homologous structures is that they are built upon similar bone structures.
Divergent evolution is responsible for Homologous structure, it is a biological process in which living organisms from a single ancestor develop and acquire certain differences based on the life they live.
What is Analogous Structure?
The features found in different living organisms that do not necessarily look identical in shape and structure but perform a similar function are considered to be part of the analogous structure. There are only parts included in analogous structure based on their similar function not because they share a common ancestor.
The changes that occur due to analogousness are to fight and survive against environmental challenges. Hence, the similar functions and traits of different species are included in the analogous structure. But it might be possible that these species had belonged to the same source or originated from a common ancestor a very long time ago.
Because it is a well-known fact that cells in living organisms are adaptable and versatile that can develop according to given climate circumstances to survive. Because of the long duration, the physical structure changes but the fundamental function they perform does not and all of this is elaborated through the analogous structure.
According to Analogous Structure, species can have homogeneous traits whether they originated from the same source or not. To examine the analogous structure, many examples are available in nature such as wings, tails, fins, etc. The most common example is fins that are found in both a penguin and a fish, they are different but share this trait.
Main Differences Between Homologous and Analogous Structures
- The homologous structure is advantageous when it comes to concluding evolutionary connection between species while analogous structure does not provide such facility.
- Homologous structure occurs so the living beings can adapt to different environments while the occurrence of analogous structure is based on the adaption of similar environments.
- Homologous structures are known to have identical development patterns. On the other hand, analogous structures do not have similar development patterns.
- The physical appearance of living organisms is typically the same when it comes to Homologous structure while the analogous structure is not based on similar anatomy.
- The homologous structure takes place due to divergent evolution. Analogous Structures, on the other hand, are the result of convergent evolution.
Conclusion
Evolution is a very subtle procedure that took place millions of years ago and is still going on. It has brought remarkable changes in the way of living.
It is considered a change in heritable specifications that need to evolve by the passage of time since there is a huge difference between the climate that existed millions of years ago and now.
In living organisms, the genes are passed to successive generations gradually by the reproduction procedure and get frequent changes and development based on the requirements of contemporary time. These changes are elaborated and explained as homologous and analogous structures.
References
- https://www.pnas.org/content/109/25/9875.short
- https://iopscience.iop.org/article/10.3847/1538-4357/ab3c1a/meta