Negritos: The earliest known inhabitants of Kerala were the Negritos (People of the Negroid race). Members of this race lived by hunting and by gathering plants and fruits. These people have dark skin and tightly curled brown hair and are less than 1.5 metres tall. Descendants of this race still inhabit the mountain regions of the state. They have a good knowledge of herbal medicine and were skilled in interpreting natural phenomena.
Australoids: After the Negritoes came the Proto-Australoids (Austrics), who spread over the whole of India. These belonged to the same race as the present-day Australian Aborigines. They represented a race of medium height, dark (in some cases black) complexion with long heads and flat noses. They laid the foundation of They introduced the cultivation of rice and vegetables and made sugar from sugarcane. They introduced snake-worship in Kerala.
Dravidians: By 700 B.C., the Dravidians (The Mediterranean People), who migrated from the Mediterranean region, spread to the whole of India especially in the south, supplanting the Austrics and Negritoes alike. The Dravidians are the ancestors of majority of the present day Malayalees. They absorbed many of the beliefs of the Negrito and Austric people, but they were strongly inclined to the worship of the Mother Goddess in all her myriad forms: Protector, Avenger, Bestower of wealth, wisdom and arts.
Aryans: After the Dravidians came the Aryans who had already settled over northern India from the Mesopotamian region. They migrated to south India during circa 300 B.C. The "white" or fair-skinned Brahmins belonged to this stock. By the advent of Aryans, caste system also formed in Kerala. The Aryans have made a deep impression on Kerala in late proto-historic times.
Today, Kerala population is the melting pot of various races, religions and ethnic groups. The vast majority of Keralites carry three racial strains in their genetic make-up; Munda, Dravidian, and Aryan. Of this, majority of today's Keralites
have a Dravidian ancestry. Nevertheless, many of them pride themselves on their Aryan descent.
The major tribes who inhabit the mountains of Kerala are Kanis, Uralis, Kadar, Kanikkar, Paniyar etc. They are considered to be the descendants of the Negrito race.