Why Do Jews Around the World Look Different? A Rabbinic Answer on Genetics, Climate, and Exile

Hello, Rabbi. How is it possible that Jews who went into exile more than a thousand years ago took on the physical appearance of the regions where they settled? For example, Moroccan Jews tend to have darker skin, while Jews from Russia or Germany are more likely to have blond hair, and so on. We can’t really say that they all intermarried with the local non-Jews (or did they?), and it also doesn’t seem possible that such large numbers of converts joined the Jewish people to introduce that much genetic variation. Doesn’t this prove either that we never truly went into exile, or that Jews did intermarry with non-Jews against halacha (assimilation)?

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Shalom and blessings,

All human beings in the world descend from Adam, the first man, so the differences you notice developed as a result of climate and environment. These are simply genetic variations, not evidence of “evolution”.

Over thousands of years, climate can indeed bring about such changes of skin color, hair type, and so forth. These traits are influenced by only a few specific genes. Even today, there are rare cases of a light-skinned child being born to dark-skinned parents, or vice versa, though of course it is unusual.

Another possibility is that some non-Jews converted to Judaism and joined Jewish communities. Their genes, which were more suited to the local climate, then spread naturally within the Jewish population.

Assimilation, however, cannot explain this. Jews who intermarried over the generations lost their Jewish identity and disappeared from our people. The only reason you and I know today that we are Jewish is because all of our ancestors married only within the Jewish people.