-The generation of Enosh and that of the flood used their knowledge and energies to manipulate plant and animal species to create new hybrids.
-Meaning, they were knowledgeable in the scientific structure of the universe and how matter manifests from its upper roots. In addition they had the ability to harness the great energies of creation.
-Using these spiritual technologies they created a great new combination of species. Although some resulted in great disaster, others contained great benefit.
-Noach refused to bring any of them on the Ark, since the whole world fell into the category of an excommunicated city, which has to be totally destroyed.
-The Torah talks about a city that does an abominable act as a whole. The impurity saturates them completely, since it was done as a unified action. The whole city must be destroyed for everything contains residue of evil.
-The generation of the flood was evil and all their creations were rooted in the klipas, they had to totally be destroyed.
-Noach did hold on to the pure original roots of the species.

(Rabbi Elchonan Wasserman in his Writings)