Bhagavatapurana 1.18.45

1.18.45

tadāryadharmaḥ pravilīyate nṛṇāṃ varṇāśramācārayutastrayīmayaḥ /
tato 'rthakāmābhiniveśitātmanāṃ śunāṃ kapīnām iva varṇasaṅkaraḥ //

45. Then (in the absence of a king) the noble and righteous course of life would disappear (in the world); as also the habits and customs of the Varnas and Ashramas laid down in the Vedas; and this would lead to the promiscuous mixing up of the Varnas among men that are intent only upon the acquisition of wealth and the gratification of the senses, as among dogs and monkeys.