There were only eight survivors of the descendants of Adam but all the races survived and the Kenites survived. This verse proves it:
1Sa 15:6 And Saul said unto the Kenites, Go, depart, get you down from among the Amalekites, lest I destroy you with them: for ye shewed kindness to all the children of Israel, when they came up out of Egypt. So the Kenites departed from among the Amalekites.
Saul lived after the flood.