Basic stucture of Forelimbs in human and birds in one suchh example of a characteristic which shows closeness of two species in evolutionary terms . The forelimbs in both the species , have similar bones structure and similar origin , but , over period of time , they have been developed to perform different suitable functions as per the need . Such organs that thave similar basic structure but perform different functions are called hologous organs . This homologous characteristic help to know that they have all evolved from a common ancestor .
