Matanga

1. Passing a period of one thousand years in that order, one attains next to the status of a Sudra. In the Sudra order, again, one has to wander for a long time. 
2. After thirty thousand years one acquire the status of a Vaisya. There, in that order, one has to pass a very long period. 
3. After a time that is sixty times longer than what has been stated as the period of Sudra existence, one becomes a person of the fighting order. In the Kshatriya order one has to pass a very long time. 
4. After a time that is measured by multiplying the period last referred to by sixty, one becomes born as a fallen Brahmana. In this order one has to wander for a long period. After a time measured by multiplying the period last named by two hundred, one becomes born in the race of such a Brahmana as lives by the profession of arms. There, in that order, one has to wander for a long period. After a time measured by multiplying the period last named by three hundred, one takes birth in the race of a Brahmana that is given to the recitation of the Gayatri and other sacred Mantras. There, in that order, one has to wander for a long period. After a time measured by multiplying the period last named by four hundred, one takes birth in the race of such a Brahmana as is conversant with the entire Vedas and the scriptures, There, in that order, one has to wander for a very long period. While wandering in that status of existence, joy and grief, desire and aversion, vanity and evil speech, seek to enter into him and make a wretch of him. If he succeeds in subjugating those foes, he then attains a high end. If, on the other hand, those enemies succeed in subjugating him, he falls down from that high status like a person falling down on the ground from the high top of a palmyra tree.

http://www.sacred-texts.com/hin/m13/m13a028.htm

Note : Explained by krishna in gita - not by birth by qualities