God knows the truth in all things ..And each and every heart ..at this point..Israel accepts any with Jewish heritage ..how they figure this out I Have no idea .One must also be aware that today many of the KENITES ( Cains children) have infiltrated the tribe of Judah and are passing themselves off as Jews and have caused and are causing much trouble for the tribe of Judah. The true JEWS of the true tribe of Judah gets blamed for many evil things that the KENITES ( Cains children) have done by passing themselves off as Jews. Revelation 2:9 and 3:9 shows us where Christ stated that He knows the blasphemy of those that say they are Jews ( of the tribe of Judah) and are not but are of the synagogue of Satan. The KENITES ( Cains children 0 have infiltrated the tribe of Judah and are calling themselves Jews and are causing much trouble for the true Jews.
It has been millennia since the flood ..those are the people we all descended from ..was there a descendant of Cain on the ARK ..we are not told ..HOWEVER ...since I really do not believe your SATAN SEED theory ..
We do know the people on the ARK were fully human ..not tainted ....WitH no mixed
Nephil or any but human DNA.