the organs counterparts are those that have a similar structure but function differently, the analogues they are the organs that fulfill similar functions despite having a different evolutionary origin.
Through comparative anatomy it is possible to find and differentiate the homologous and analogous organs of the different organisms by contrasting them.
| Homologous bodies | Analogous organs | |
|---|---|---|
| definition | Organs similar in their structure with different functioning. | Those organs with a different origin that perform the same function. |
| Characteristics |
|
|
| Type of evolution | divergent | convergent |
| presence | It can be observed in species that live in different environments. | They are present in species that live in similar environments. |
| examples | The wings of bats and the arms of a chimpanzee are homologous organs | The wings of bats and the wings of birds are analogous organs |
What are homologous organs?
Homologous organs are what they are similar to their internal structurebut that they fulfill different functions depending on the species.
Homology is usually presented in bodies because they come from a common ancestral organ.
The functions performed by the homologous organs can become completely different because the species have adapted to the characteristics of the environment in which they develop.
The development of the homologous organs happens thanks to the divergent evolutionwhere two related species change a common ancestral structure during their evolution in order to survive by performing different functions.
That is why it is said that the organs are homologous when they have the same evolutionary originthat is, a common ancestor, even if they have evolved to fulfill functions with different purposes.
Example: Vertebrate forelimbs such as the arms, wings of birds, and fins of a dolphin are homologous organs because they come from the same common ancestor, while performing completely different functions.
What are analogous organs?
Analogous organs are those that are morphologically similar or carry out similar functions despite having one different genetic origin.
This means that the origin and embryonic development of analogous organs is not the same, even if their structure is similar or they fulfill the same function.
Usually, the analogy occurs when species have evolved separately but had to adapt to the same type of environment.
This development process is possible thanks to the convergent evolution. Here, organisms that have had to evolve completely separately develop similar characteristics due to the fact that the environmental conditions in which they develop are quite similar.
Sharks and dolphins are two species that have had to evolve convergently.
Example: The wings of birds and insects are morphologically different, but they both serve the same function because they allow these species to fly.
PhD in Biochemistry from the Venezuelan Institute of Scientific Research (IVIC), with a degree in bioanalysis from the Central University of Venezuela.