The diverse racial and cultural origins of India's people are bound intricately with the other societies of the Indian subcontinent, including the inhabitants of Pakistan, Bangladesh, Nepal, Bhutan, and Sri Lanka.
The geographical barriers of the Himalayan mountain range mingled the indigenous peoples with the successive waves of migrants from the northwest and the northeast of the subcontinent. But environmental and historical factors favored the coexistence of many different peoples with distinct physical and cultural characteristics. India ranks second only to China among the world's most populous countries, with a population that exceeds 1 billion. One half of Indian adults are illiterate, more than half of all children are undernourished, and one third of the people live below the poverty line.
Each year, India adds 18 million people, roughly another Australia. By 2050, U.N. demographers project that it will have added another 530 million people for a total of more than 1.5 billion. If India continues on the demographic path as projected, it will overtake China by 2045, becoming the world's most populous country.
Approximately seven percent of the total population belongs to more than 300 "scheduled" tribes. These tribal or aboriginal groups are racially and culturally distinct from the mainstream of Indian population and also tend to vary considerably among themselves. The major religious groups are Hindus (83 percent), Muslims (11 percent), Christians (two percent), Sikhs (two percent), Buddhists (0.7 percent), and Jains (0.5 percent).
