Two organs which are similar in structure and origin, but not necessarily in function are called :

Homologous organs are similar in structure and origin but not necessarily in function. Hence, organs from different species having a similar basic form, microscopic structures, body positions and embryonic development are said to be homologous. Homologous structures showing adaptations to different environmental conditions and modes of life are examples of adaptive radiation. The fossils of prehuman and ancestral human forms are obtained form widely diverse regions of Africa, Asia and Europe, which indicates that man's center of origin was probably in Asia and Africa. More precisely man has originated in central Asia because the number of domesticated animals and plants is maximum in Asia and the oldest known fossils have been obtained from Asia, China, Java and India. Climatic conditions in Asia and nearby places were most conductive for human evolution.