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Non-halachic Reform Jews are those whose mother was not Jewish, yet they consider themselves Jewish because of either a heterodox conversion or patrilineal descent. We can mostly figure out the demographics from particular questions asked in certain surveys. According to the 2013 Pew Study on American Jews, 10% of American adults who identify their religion ...


6

In the US, about 1.5% of self-identified Orthodox Jewish adults say they had a formal conversion, according to data from Pew's 2013 survey of American Jews. This amounts to about ~7000 people. (According to this article, the RCA says that 1275 people had converted with an RCA-affiliated beit din over a seven-year period, although, as the article says, plenty ...


3

Rabbi Henkin, in his book New Interpretations on the Parsha, suggests three possible reasons: Malnourishment as slaves may have lead to a high number of miscarriages. Because Egypt places high prestige on first-borns, perhaps the Jewish first-borns did not want to leave Egypt, and stayed behind/died when the Jews left. If, according to the medrash, the ...


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To add to the other answers: Environmental factors can cause genes to be expressed or repressed, and changes in gene expression can be heritable. It's possible that a single human's DNA could contain repressed genes with the potential for many ethnic appearances, and environmentally induced changes in expression of these genes could be heritable. (...


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In the United States in 2012, 1,570,976 of the 3,952,841 live births, or 39.7%, were the first live birth to that mother. Among mothers listed as non-Hispanic and white (which I mention only because I think the vast majority of Jews in the States are so listed and the category is available to me), 895,171 of the 2,134,044 live births, or 41.9%, were the ...


2

I have found Nefesh b' Nefesh's community database to be an excellent resource for this sort of information. Jerusalem is of course a fantastic place in Israel for Torah learning because of the quantity of diversity of opportunities to learn. Ramat Beth Shemesh is more of a city where people live and has less yeshivot and learning places for adults. Two ...


2

It varied tremendously across Europe. World War I actually demolished a lot of communal structure, and Orthodox observance declined from there. Rabbi Joseph Soloveichik commented that as a young child he recalled when most Jews kept shabbos, and by the time he was a young man that had changed. As a college student passing through the great city of Vilnius, ...


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What's the problem? I know families with multiple generations of mostly (or all) boys. There's a family that comes to mind with something like 6 brothers who are mostly married, and there are now between 4 and 6 sons to each of those brothers. In all, the grandfather has about 24 or 25 grandchildren. If I'm not mistaken there is one granddaughter among them. ...


1

Firstly, it is highly unlikely that the Jews were in fact greater in numbers and strength than the Egyptians. Many Mefarshim there in Shemos 1:9 (e.g. R' Avraham ben Harambam, Malbim, Hakesav Vehakabbalah, and more) note that רב ועצום ממנו does not literally mean that there were more Jews than Egyptians. Even according to those who do interpret it that way,...


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With genetic testing, this figure can only get more and more accurate over time. This article argues that science proves that 75% of Jews trace back to the middle east: http://www.haaretz.com/jewish-world/jewish-world-news/.premium-1.626156 Im not sure it would be possible to trace much more accurately than this.


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Recent genetic studies show that male offspring tend to follow their father's trends in their own offspring. In other words, if there are a large number of males in a family, those males in turn, go on to produce a larger proportion of males to females (and the converse is true). The conjecture is that the weighting of male/female sperm is passed on to ...


1

Male vs female is not blind 50-50%, it depends on us too. As mentioned in Niddah 31a (last line), with some effort one can make his wife to born just boys. If you see further on 31b you can see such a phrase אמר רב קטינה יכולני לעשות כל בני זכרים my translation: Rav Ktina told: I can make all my children to be boys. If Rav Ktina could, I think that ...


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While not specific to Reform Jews, the National Jewish Population Survey from 2000-01 (which was just enough time after Patrilineal Descent for college kids to have been born) the found that only 48% of Jews in college had two Jewish parents. Which would mean that 26% of Jews in college have only a Jewish father, and thus aren't halachically Jewish (and this ...


1

The Mishna (Kilaim 8:6) spoke almost 2000 years ago about micro-evolution: "Rabbis: the wild ox is a species of "behema", Rabbi Yossi says: it is a species of "chaya", Bartenura: "The Rabbis hold it used to be domesticated but it fled civilization and eventually transformed into the wild ox specie". There's a fascinating book by Dr. Lee Spetner called "Not ...


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