The so called Jewish markers from what i have seen are just Y DNA haplogroups that are common in mainly European Jews. Alot of times they will have their own subclades or everyone will have the same Y DNA haplogroup because of a population bottleneck and they pretty much only breed with each other or their group of Jews. Orignally The ancient jews were just typical people in the area of Israel, Syria, and Palestine from what i know there would not have been really anything unque about them genetically except maybe Y DNA haplogroup from Abraham or important leaders in the Bible like King David.
white Jews in the western World have a little more European blood since almost all genetic's, Scientits, Historians, or whatever people that have to do with DNA and genetic's are European or western. They are very intrested in Jews which makes sense when u look at history of the western world so there have been tons of studies on Jewish people. On the globe13 aust dna test Ashkenazi jews i think from Germany are
Med=37.8%( most confusing group peoplular in Europe, mid east, and north africa), west asian(40-50% from Caucus, Anatolia to Pakistan but less than 40% once u get as south Syria)= 22.7%, Southwest asian(mainly around Arabia, Syria area, and north Africa) North Euro(Paloithic aka Cro magnon European)=16.7%, Then they had like 0,3% siberian native american and other stuff which probably is not real ancestry and not significant.
These are results from Samratiens who are mentioned in the new testament one story the parble of the good smaratien. They used to be Jews but they left the Jewish faith but they think they are the real Jews and the bible says they mixed with Gentiles. They also have only breed with each other for i think as long as they have existed so for well over 2,000 years this has caused them to die from dises that occur when u breed with close relatives. So there are only about 700 left. I would think they are the closest reltives to ancient Jews. There have been globe13 aust dna tests on every single one these are the averages.
Southwest asian=41.3%, west asian=28.8%, med=28.4%, east african=1.4%(east africans have had contact with mid easterns and north African Caucasians for well over 10,000 years. 9,000 year old Syrian mtDNa proves it also in the Bible Moses had a Ethiopian wife so makes sense).
So probably about 9% of Askenazi Jews med is from European inter marriage, All 16.7% of their north euro is from European inter marriage, 7-20% of their west asian is from european inter marriage, and 4-15% of their southwest asian. So over all at least 37% of their aust DNA globe13 results are from European inter marriage. i dont know how exact the percentages are but i would guess their about 50% European.
I dont know that much about the history of Ashkenazi Jews but it seems they settled mainly around the Rhine in Germany and eastern Europe in 600's after Muslim invasion of Isreal. So here are German globe13 aust dna results, and German samartien mix, Greek Samartian and german-greek Samartien mix.
Germans
North Euro=59.2%, med=29.7%, west asian= 7.3%, southwest asian=3.6%
German-Samaritan mix
north euro=29.6%, med=24.25%, southwest asian=22.45%, west asian=18.05%
Greek Samartien mix
med=33.05%, southwest asian=28.2%, west asian=25.85%, north euro=12.1%
Ashkenazi Jews
med=37.8%, west asian=22.7%, southwest asian=20.6%, north euro=16.7%
German-Greek-Samratian mix
med=30.975%, North Euro=26.9%, west asian=20.475%, southwest asian=18.775%,
I dont know it seems Ashkenazi Jews are mainly a mix of noon German Europeans. Probably ones with alot of meditreaen and more west Asian than most Europeans like Greeks or Italians.