What Are Homologous Structures/Organs?
Many species have similar traits because they are descendants of a single common ancestor. These species developed from a single source and are related to a certain degree despite their current differences. The traits they share are referred to homologous structures.
A homologous structure is an organ or body part that appears in different animals and is similar in structure and location, but doesn’t necessarily share the same purpose. This type of evolution is referred to as divergent evolution. An example of homologous structure is the forelimb of a frog and man seems to be built from same basic design of bones but they perform different functions.
What You Need To Know About Homologous Organs
- Homologous organs are those organs which are structurally similar but perform different functions.
- They differ morphologically.
- Homologous organs show adaptive radiation (divergent evolution).
- They develop in related organisms.
- They perform different functions.
- They have similar development pattern.
- Homologous organs have a similar development stages.
- They have similar internal structure.
- Examples of homologous organs include the forelimb of a man, front leg of bull or dog.
What Are Analogous Structures/Organs?
Species may also have similar traits even though they are not related to each other. This usually results because the species live in similar environments and fill similar ecological roles. The structures in this case are referred to as analogous structures.
Analogous structures can therefore be defined as biological structures having similar or corresponding functions but not from the same evolutionary origin. In other words, species use these biological structures for same purpose and yet these species are from unrelated evolutionary lines. This form of evolution is referred to as convergent evolution.
For example, the wings of an insect, bird and bat would all be analogous structures. They all evolved to allow flight, but they did not evolve at the same time, since insects, birds and mammals all evolve the ability to fly at different times.
What You Need To Know About Analogous Organs
- Analogous organs are those organs which perform same function but are structurally different.
- They show superficial resemblance.
- Analogous organs show convergent evolution.
- They develop in unrelated organisms.
- They perform similar function.
- They have dissimilar development patterns
- Analogous organs have different development stages.
- Their internal structure is quite different.
- Examples of analogous organs are wings of flying animals like bat, birds and insects and tail fin in fish. Bird wings are covered by feathers all along the arm but wings of a bat is skin folds stretched between elongated fingers.
Between Homologous And Analogous Structures/Organs In Tabular Form
|BASIS OF COMPARISON||HOMOLOGOUS STRUCTURES/ORGANS||ANALOGOUS STRUCTURE/ORGANS|
|Description||Homologous organs are those organs which are structurally similar but perform different functions.||Analogous organs are those organs which perform same function but are structurally different.|
|Morphology||They differ morphologically.||They show superficial resemblance.|
|Type Of Evolution||Homologous organs show adaptive radiation (divergent evolution).||Analogous organs show convergent evolution.|
|Development||They develop in related organisms.||They develop in unrelated organisms.|
|Function||They perform different functions.||They perform similar function.|
|Development Pattern||They have similar development pattern.||They have dissimilar development patterns|
|Development Stages||Homologous organs have a similar development stages.||Analogous organs have different development stages.|
|Internal Structure||They have similar internal structure.||Their internal structure is quite different.|
|Examples||Examples of homologous organs include the forelimb of a man, front leg of bull or dog.||Examplesof analogous organs are wings of flying animals like bat, birds and insects and tail fin in fish. Bird wings are covered by feathers all along the arm but wings of a bat is skin folds stretched between elongated fingers.|