ADAPTIVE RADIATION IN MAMMALS

ADAPTIVE RADIATION IN MAMMALS

The evolutionary process in which single species gets diverse into a variety of forms which occupy different habitat is called Adaptive Radiation or divergent evolution. In 1999 the concept of adaptive radiation or divergent evolution was developed by Osborn.  According to him the adaption radiation is the differentiation of animals form and construction which a common point and follows a land of adaption in diverse direction in respond to different need demands different environment.

Adaptive radiation is also known as macro-evolution which involves change of species generic level. During these evolutionary several changes occur as well as new structured are formed which makes the organism adapt in new environment. In Mesozoic era mammals are small, generalized and rare, the age of reptiles when the dinosaurs were at the peak of their evolution just after extinction of dinosaurs by the end of Mesozoic era and beginning of Cenozoic mammals, expanded to varied evolutionary patterns. Early in Cretaceous period placental mammals differentiate from marsupial.

On the basis of limb structure, teeth and with special features adaptive radiation in mammals can be discussed as follows. It was modern shrew like ancestor with 5-toes plaint grade limbs from where five basic patterns of adaptations namely aquatic, Volant, cursorial, fussorial, and arboreal evolved by modification of limbs. They have different types of teeth and also have special features on o body for better adaption as well as survival in the earth.