Lord Shri Krishna said regarding four Natures to Arjuna in Bhagavad Gita.
In this Sloka of Bhagavad Gita:
ब्राह्मणक्षत्रियविशां शूद्राणां च परंतप।
कर्माणि प्रविभक्तानि स्वभावप्रभवैर्गुणैः।।18.41।।
"The nature of Brahmanas, Ksatriyas, Vaisyas, and Sudras are due to their respective inherent dispositions. The meaning is that their past Karma has been the cause of determining births as Brahmanas etc. The Sattva and other Gunas are the result of such Karma.... The duties and works assigned to them according to the Gunas constituting their inherent nature, are expounded and allotted by the Sastras in the order described."
Here I m only talking about the four Natures Brahmanas, Ksatriyas, Vaisyas, and Sudras. So, How four Natures came into existence according to Scripture?