Adaptive convergence in Evolution
In this type of evolution, the organisms with completely different body organization possess superficial resemblance. It means that the organisms of different classes acquire similar characteristics independently and separately to avail similar environment. This is also known as ‘parallel evolution’.
Examples: The most common example of convergent evolution is the development of ‘wings’ in insects, flying reptiles (Draco), birds and flying mammals (Bats). All of them belong to different groups and possess one common character is the “development of wings” for flight.
The aquatic vertebrates- cartilaginous & bony fishes, aquatic reptiles (Extinct - Ichthyosaurs), and dolphins, porpoises and whales (aquatic mammals) are all superficially alike. All these are having stream-lined body with a median dorsal fin, a caudal fins and paired fin. In aquatic reptiles and mammals the forelimbs are modified into flippers. If a layman is asked, he says all are fishes because of their superficial resemblances and environment. But it is clearly evident that their, body organization is markedly different.
The burrowing mammals- Moles and gophers, forelimbs are modified for digging the soil. But these two belongs to two different orders (Moles- lnsectivora and gophers - Rodentia of the class mammalia.
The convergent evolution leads to the production of analogous similarities among different groups of organisms. This indicates that evolution ma1 lead to superficial resemblances. It could be concluded that in the origin of life from simple to more complex forms, both divergence and convergence have played a vital role. However, the divergence is more frequent at present than the convergence.