Every habitat imposes a particular environmental impact on man, his domestic animals and crops. This impact varies widely since man makes a variety of adjustments to the challenges issuing from the physical and organic components, its living being changed to meet the demands of the organism. Thus the biodiversities in Body Size, Body Shape, Body Physique and Physiological variations occur in human inlieu with social activities and it is necessary in dealing with the demands of the environment. Present book deals with the Biological variability in two endogamous tribal groups of India, namely Malayali and Malakkuravan. They are bio-culturally unique indigenous people who live in harmony with nature in Jawadhi Hills and the adjoing forests.