One theory suggested that a nomadic, Indo European tribe, called the Aryans, invaded and conquered the Indus Valley Civilization. The eastward shift of monsoons may have reduced the water supply, forcing the Harappans of the Indus River Valley to migrate and establish smaller villages and isolated farms.
Natural rights are rights that are used by everyone universally in the world. These rights cannot be taken away. Typically these rights include life, liberty, and the pursuit of happiness.