Homology in biology is existence of the shared ancestry between the pair of structures or the genes present in the different taxa.
<u>The most common example of the homologous structures is forelimbs of the vertebrates, where wings of the bats, arms of the primates, front flippers of the whales and forelegs of the dogs and the horses are all derived from same ancestral tetrapod structure. </u>
Homologous structures can be explained by evolutionary biology which states that these are adapted to the different purposes as result of the descent with the modification from common ancestor.
