Have the majority of Jews intermarried a lot over the centuries or not?

Question

Over the centuries was there a lot of conversions or intermarriage or both, or have Jews for the most part largely just stuck to themselves thus retaining a lot of the DNA of the original ancient Israelites/Hebrews?

Answer 1

Marriage outside the faith was not overly common until the 19th century.  Only in the West has such marriage become common.  Conversions were few also until recently and again are centered in the West.

Rape was a common problem for the Jewish community and was such a problem that the religious leaders came up with the solution that any child born of a Jewish woman was considered of Jewish blood.  Outside of that, most Jewish communities tended towards marriage only within the community (again until the last century or so).  Because of what amounted to inbreeding, some diseases such as Tay-Hachs are commonly only found in people of eastern European Jewish descent.

Today's Jews are more likely to include converts and interfaith marriages.  Not all Jewish sects agree with this but it is occuring more frequently.

Answer 2

During the middle ages, Jewish people were either forced to convert to Christianity, or were persecuted and forced to live in walled communities. Intermarriage was forbidden  outside of their faith by their own religious beliefs or from the Christian governments of the countries that they lived in. With the passage of time, some secular Jewish people  married outside of their faith. Today the Jewish community in the US is less than 4%. Intermarriage and assimulation into a secular society have dropped the numbers of individuals who identify themselves as Jewish. Since the Jewish population of the early to late middle ages were forced to live in walled communities, certain genetic traits and disorders became more frequent.  Populations had little or no new infusion of DNA.