There are many definitions of who is Jewish – including in terms of nation (Israel), religion (Judaism) and ethnicity – but perhaps the simplest is this: a person is Jewish if they self-identify as such.
Jews come in all shapes, sizes, ethnicities and nationalities. There are black Jews from Ethiopia, Chinese Jews from Shanghai and Indian Jews. There are Jews from Morocco and Iran, Jews from South America and Oceania. The practices and beliefs held by Jews range from those who openly identify as Orthodox and strictly observe ancient precepts to those that have nothing to do with the religion or culture.
In Israel, the definition corresponds to the dominant nationality. The Jewish status of a person is registered and controlled by the Israeli Ministry of the Interior, which requires a person to meet the halakhic definition to be registered as a “Jew.” According to Jewish law, a child born to a Jewish mother or an adult who has converted to Judaism is considered a Jew; one does not have to reaffirm their Jewishness or practice any of the laws of the Torah to be Jewish. Israel’s Central Bureau of Statistics estimated the Israeli Jewish population was 5,901,000 in December 2011 (75.3% of the total population).
The Jewish population data represent DNA samples from 124 Jewish individuals in the collection of The National Laboratory for the Genetics of Israeli Populations, at Tel-Aviv University. Samples were obtained by the Genetics Laboratory of the Biology Dept. at Spain’s University of the Balearic Islands (Laboratori de Genetica, Dept. de Biologia, Universitat de les Illes Balears), and research was supported by a grant from Spain’s General Direction of Higher Education (Direcciòn General de Enseñanza Superior). One researcher also received a fellowship from Spain’s Ministry of Education and Culture (Ministerio de Educaciòn y Cultura). Samples were separated into four sub-populations of:
a) Ashkenazi [25 people (Ashkenazi Jews)];
d) Oriental [12 Iranians (Persian Jews); (Iran Jews)]; [13 Iraqis, (Iraqi Jews; Iraqi jews babylonian jews)]. Oriental Jews also are called Mizrahi ( (Mizrahi Jews; The Ashkenazi, Sephardi and Oriental).
The word Jew is a derivative of the word Judah and refers to a descendant of the Kingdom of Judah, which arose from the Tribe of Judah, one of the original tribes of Israel named after the son of Jacob (Tribe of Judah; Judah Tribe Of). The biblical region of Judea, which housed the city of Jerusalem, is in what today is southern Israel. As the Jews migrated farther from the Holy Land, subpopulations grew for Sephardic Jews –from Spain, Portugal, North Africa and the Middle East– and for Ashkenazi Jews –who speak Yiddish and are from France, Germany and Eastern Europe (Ashkenazic and Sephardic Jews). For more details, see:
From Ashkenazi Jews: “A 2010 study on Jewish ancestry by Atzmon-Ostrer et al. stated ‘Two major groups were identified by principal component, phylogenetic, and identity by descent analysis: Middle Eastern Jews and European/Syrian Jews. The [analysis] suggested similar origins for European Jewry and refuted large-scale genetic contributions of Central and Eastern European and Slavic populations to the formation of Ashkenazi Jewry.’ Both groups –the Middle Eastern Jews and European/Syrian Jews– shared common ancestors in the Middle East about 2,500 years ago. The study … shows that the Jewish groups (Ashkenazi and non-Ashkenazi) share large swaths of DNA –indicating close relationships– and that each of the Jewish groups in the study (Iranian, Iraqi, Syrian, Italian, Turkish, Greek and Ashkenazi) has its own genetic signature, but is more closely related to the other Jewish groups than to their fellow non-Jewish countrymen.
Atzmon’s team found that the SNP markers in genetic segments of 3 million DNA letters or longer were 10 times more likely to be identical among Jews than non-Jews. Results of the analysis also tally with biblical accounts of the fate of the Jews. Using their DNA analysis, the authors traced the ancestors of all Jews to Persia and Babylon — areas that now form part of Iran and Iraq. The study also found that with respect to non-Jewish European groups, the population most closely related to Ashkenazi Jews is modern-day Italians. The study speculated that the genetic similarity between Ashkenazi Jews and Italians may be due to inter-marriage and conversions in the time of the Roman Empire. It was also found that any two Ashkenazi Jewish participants in the study shared about as much DNA as fourth or fifth cousins.”
Source publication: Jewish Population Genetic Data in 20 Polymorphic Loci, FSI, 2002, p52-58.