According to Hinduism, there are many intelligent races like human (manushya/nara), asura, deva, gandharva, etc. Indians in Bharatavarsha are obviously manushya because the shastras say so. But how do we know that non-Indians like Chinese, Native Americans, blacks, Europeans, Africans, etc. are all "manushya"? It is possible that instead of being manushyas of the "mleccha" varna, they could be descended from asuras, rakshasas, etc.
Does Hindu scripture give a way of identifying who is a "manushya"?