The remainder assimilated. Their "Hebrew" DNA passed throughout the generations into a much, much larger pool, and became so diluted as to not really be measurable.
On the other hand, in areas where vast numbers of Jews were forcibly converted and assimilated, distinctive Hebrew DNA signatures have been left. A case in point, as I mentioned earlier, is Spain - where 20% of the population has verifiable Jewish ancestry through genetics. Or, for that matter, the Palestinians, who have strong genetic influences not only from Arabs, but also from Jews, Samaritans, Greeks and European Crusaders who assimilated over the centuries.
Unlike the descendants of Jewish-Christians (where, after 80 generations or so, their Hebrew DNA is minimal), most modern Jews (Ethiopians and modern converts excluded) have a very strong component of "original" Hebrew DNA -- likely more than 50%. That's why we can categorize something as "Jewish/Hebrew" DNA in the first place -- because there are certain markers found in Jewish populations at very high frequencies.
Again I am speaking of *Genetics* Since all people originated from Noah a Gentile you have people that were Israelites which were not all Jews..
So if you take the Ancient World and divide all the people up on the Planet all you have are people from one of one the 12 Tribes of Israel and gentiles.... Based upon that fact alone, no records during that time could account for all the people on the earth and say wether they were from one of the tribes of Israel...
Maybe you are saying certain tribes have genetic markers, but to say all tribes from Israel carry the same Hebrew DNA seems out of the realm of human possibilities.
The Bible speaks of Israel and basically the Jews of Israel and the expansion of Christianity from Judasim..
To dis-count all other people on the planet by saying they did not have an inheritance of Hebrew DNA because the Bible does not address certain tribes and those people seems a bit arrogant IMHO.
People gathered all over the earth based on many things in addition to religion, race, language culture and personal rituals and practices...
One other thing Nostradamus was born a Jew converted to Christianity had many many children do they no longer have Hebrew DNA?
The Jews in the world over the last 2000 yrs who converted to other religions would be impossible to identify...
Because it is not a race...
You see it differently?