Total online: 1
Генетско порекло Јевреја
Велик развој модерне популационе генетике током 90-тих година 20.
века, као и велико интересовање за порекло Јевреја, резултовао је
спровођењем великог броја генетских студија, јеврејског становништва
раштрканог по целом свету. Ове студије омогућиле су разјашњавање
историјских недоумица, али и тенденциозних антисемититских тврдњи о
пореклу Јевреја. Студије популационе генетике показале су да јеврејски
народ највећим делом (ашкенаски Јевреји, сефардски Јевреји, Јевреји који
су током дијаспоре живели у блискоисточним земљама и земљама северне
Африке, тзв. Мизрахи Јевреји, воде порекло од древног блискоисточног
Генетска студија линије мушког порекла, Y-ДНК, која се наслеђује по
очинској линији, спроведена током 2000. године од стране велике групе
међународних стручњака и обљављена у издању америчке националне
академије наука, показала је да јеврејске заједнице у Европи, Северној
Африци, Блиском Истоку и Америци имају заједничко блискоисточно генетско
порекло. Студија је обухватила 1329 особа из 29 различитих држава
Друга велика студија објављена исте године, утврдила је да око 70%
јеврејског становништва у Израелу води директно генетско порекло од
староседелачког становништва, које је хиљадама година живело на том
Студије мајчинске митохондријалне ДНК, спроведене током 2006. године од
стране Бехара и сарадника, показале су да ашкенаски Јевреји воде
порекло од 150 блискоисточних жена.
Белика трансгеномска студија аутосомалне ДНК спроведена под
покровитељством њујоршког колеџа "Алберт Ајнштајн" током 2010. године,
искључила је било какву значјну генетску контрибуцију туркијског
хазарског народа у формирању данашњих ашкенаских Јевреја, (што је често
потенцирано у антисемитским круговима) и слично претходним генетским
студијама потврдила заједничко блискоисточно порекло Јевреја.
Иако је преласка у Јудаизам кроз векове било, с обзиром на верска
ограничења било их је мало, те је у оквиру генетске студије Бехара и
сарадника 2004. године, укупни генетски инпут европске популације у
формирању ашкенаске јеврејске заједнице израчунат на 12,8%
studies indicate various lineages found in modern Jewish populations;
however, most of these populations share a lineage in common, traceable
to an ancient population that underwent geographic branching and
subsequent independent evolutions. While DNA tests have demonstrated both inter-marriage and conversion to Judaism in all of the various Jewish ethnic divisions over the last 3,000 years, it was substantially less than in other populations.
The findings lend support to traditional Jewish accounts accrediting
their founding to exiled Israelite populations, and counters theories
that many or most of the world's Jewish populations were founded
entirely by local populations that adopted the Jewish religion, devoid
of any actual Israelite genetic input.
DNA analysis further determined that modern Jews of the priesthood tribe—"Kohanim"—share an ancestor dating back about 3,000 years. This result is consistent for all Jewish populations around the world. The researchers estimated that the most recent common ancestor of modern Kohanim lived between 1000 BCE (roughly the time of the Biblical Exodus) and 586 BCE, when the Babylonians destroyed the First Temple. They found similar results analyzing DNA from Ashkenazi and Sephardi Jews.
The scientists estimated the date of the original priest based on
genetic mutations, which indicated that the priest lived roughly 106
generations ago, between 2,650 and 3,180 years ago depending whether one
counts a generation as 25 or 30 years.
These Jews belong to the haplotypes J1e and J2a. However, more recent
research has shown that many ethnic groups in the Middle East and
Mediterranean area also share this genetic profile.
Although individual and groups of converts to Judaism have
historically been absorbed into contemporary Jewish populations, it is
unlikely that they formed a large percentage of the ancestors of modern
Jewish groups, and much less that they represented their genesis as
Biologist Robert Pollack stated in 2003 that one cannot determine the biological "Jewishness" of an individual because "there are no DNA sequences common to all Jews and absent from all non-Jews". A 2009 study was able to genetically identify individuals with full or partial Ashkenazi Jewish ancestry.
Male lineages: Y chromosomal DNA
A study published by the National Academy of Sciences found that "the paternal gene
pools of Jewish communities from Europe, North Africa, and the Middle
East descended from a common Middle Eastern ancestral population", and
suggested that "most Jewish communities have remained relatively
isolated from neighboring non-Jewish communities during and after the
Diaspora". Researchers expressed surprise at the remarkable genetic uniformity they found among modern Jews, no matter where the diaspora has become dispersed around the world.
Other Y-chromosome findings show that the world's Jewish communities are closely related to Kurds, Syrians and Palestinians.
Skorecki and colleague wrote that "the extremely close affinity of
Jewish and non-Jewish Middle Eastern populations observed ... supports
the hypothesis of a common Middle Eastern origin".
According to another study of the same year, more than 70% of Jewish
men and half of the Arab men (inhabitants of Israel and the territories
only) whose DNA was studied inherited their Y-chromosomes from the same
paternal ancestors who lived in the region within the last few thousand
years. The results are consistent with the Biblical account of Jews and
Arabs having a common ancestor. About two-thirds of Israeli Arabs and
Arabs in the territories and a similar proportion of Israeli Jews are
the descendants of at least three common ancestors who lived in the
Middle East in the Neolithic
period. However, the Palestinian Arab clade includes two Arab modal
haplotypes which are found at only very low frequency among Jews,
reflecting divergence and/or large scale admixture from non-local
populations to the Palestinians.
A study of haplotypes of the Y-chromosome, published in 2000, addressed the paternal origins of Ashkenazi Jews. Hammer et al. found that the Y chromosome
of some Ashkenazi and Sephardi Jews contained mutations that are also
common among Middle Eastern peoples, but uncommon in the general
European population. This suggested that the male ancestors of the
Ashkenazi Jews could be traced mostly to the Middle East. The proportion
of male genetic admixture
in Ashkenazi Jews amounts to less than 0.5% per generation over an
estimated 80 generations, with "relatively minor contribution of
European Y chromosomes to the Ashkenazim," and a total admixture
estimate "very similar to Motulsky's average estimate of 12.5%." This
supported the finding that "Diaspora Jews from Europe, Northwest Africa,
and the Near East resemble each other more closely than they resemble
their non-Jewish neighbors." However, when all haplotypes were included
in the analysis, m (the admixture percentage) increased to 23% ± 7%. In
addition, of the Jewish populations in this cluster, the Ashkenazim were
closest to South European populations, specifically the Greeks.
In Jewish populations, Haplogroup J1 (defined by the 267 marker) constitutes 30% of the Yemenite Jews 20.0% of the Ashkenazim results and 12% of the Sephardic results. However, J1 is most frequent in Yemen (76%), Saudi (64%), Qatar (58%). J1 is generally frequent amongst Negev Bedouins (62%). It is also very common among other Arabs such as those of the Levant, i.e. Palestinian (38.4%), Syria (30%), Lebanon (25%). In Europe, higher frequencies have been reported in the central Adriatic regions of Italy: Gargano (17.2%), Pescara (15%), in the Mediterranean Paola (11.1%) and in South Sicilian Ragusa (10.7%). Fairly high frequencies have also been reported in other nearby Mediterranean areas: Crete (8.3%), Malta (7.8%), Cyprus (6.2%), Greece (5.3%).
Female lineages: Mitochondrial DNA
Before 2006, geneticists largely attributed the genesis of most of the world's Jewish populations
to founding acts by males who migrated from the Middle East and "by the
women from each local population whom they took as wives and converted
to Judaism", though no genetic relation was found between Jewish and non
Jewish female lineages. However, more recent findings of studies of
maternally inherited mitochondrial DNA, at least in Ashkenazi Jews, has led to a review of this archetype.
This research has suggested that, in addition to Israelite male,
significant female founder ancestry might also derive from the Middle
East-with 40% of Ashkenazim descended from four women lived about
1000–1500 years ago in the Middle East.
In addition, Behar (2006) suggested that the rest of Ashkenazi mtDNA is
originated from about 150 women, most of those were probably of Middle
Eastern origin. Approximately 32% of people with Ashkenazi Jewish
ancestry belong to the mtDNA haplogroup K. This high percentage points
to a genetic bottleneck occurring some 100 generations ago.
Research in 2008 found significant founder effects in many non-Asheknazi Jewish populations. In Belmonte, Azerbaijani, Georgian, Bene Israel and Libyan
Jewish communities "a single mother was sufficient to explain at least
40% of their present-day mtDNA variation". In addition, "the Cochin and Tunisian Jewish communities show an attenuated pattern with two founding mothers explaining >30% of the variation." In contrast, Bulgarian, Turkish, Moroccan and Ethiopian
Jews were heterogeneous with no evidence "for a narrow founder effect
or depletion of mtDNA variation attributable to drift". The authors
noted that "the first three of these communities were established
following the Spanish expulsion and/or received large influxes of
individuals from the Iberian Peninsula and high variation presently
observed, probably reflects high overall mtDNA diversity among Jews of
Spanish descent. Likewise, the mtDNA pool of Ethiopian Jews reflects the
rich maternal lineage variety of East Africa." Jewish communities from Iraq, Iran, and Yemen showed a "third and intermediate pattern... consistent with a founding event, but not a narrow one".
In this and other studies Yemenite Jews differ from other Mizrahim, as well as from Ashkenazim, in the proportion of sub-Saharan African gene types which have entered their gene pools. African-specific Hg L(xM,N) lineages were found only in Yemenite and Ethiopian Jewish populations. Among Yemenites, the average stands at 35% lineages within the past 3,000 years.
Genome-wide association and linkage studies
In genetic epidemiology, a genome-wide association study
(GWA study, or GWAS) is an examination of all or most of the genes (the
genome) of different individuals of a particular species to see how
much the genes vary from individual to individual. These techniques were
originally designed for epidemiological uses, to identify genetic
associations with observable traits.
A 2006 study by Seldin, et al. used over five thousand
autosomal SNPs to demonstrate European genetic substructure amongst the
Ashkenazi. The results showed "a consistent and reproducible distinction
between 'northern' and 'southern' European population groups". Most
northern, central, and eastern Europeans (Finns, Swedes, English, Irish,
Germans, and Ukrainians) showed >90% in the 'northern' population
group, while most individual participants with southern European
ancestry (Italians, Greeks, Portuguese, Spaniards) showed >85% in the
'southern' group. Both Ashkenazi Jews as well as Sephardic Jews showed
>85% membership in the "southern" group. Referring to the Jews
clustering with southern Europeans, the authors state the results were
"consistent with a later Mediterranean origin of these ethnic groups".
A 2007 study by Bauchet, et al. found that Ashkenazi Jews were
most closely clustered with Arabic North African populations when
compared to Global population, and in the European structure analysis,
they share similarities only with Greeks and Southern Italians,
reflecting their east Mediterranean origins.
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 (IBD) analysis: Middle Eastern Jews and
European/Syrian Jews. The IBD segment sharing and the proximity of
European Jews to each other and to southern European populations
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.", as both groups—the
Middle Eastern Jews and European/Syrian Jews shared common ancestors in
the Middle East about 2500 years ago. The study examines genetic markers
spread across the entire genome and 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 non Jewish fellow 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 are 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
A 2010 study by Bray et al, using SNP microarray techniques and linkage analysis,
estimated that 35 to 55 percent of the modern Ashkenazi genome is
specifically traceable to Europe, and that European "admixture is
considerably higher than previous estimates by studies that used the Y
chromosome". The study assumed Druze and Palestinian Arabs
populations to represent the reference to world Jewry ancestor genome.
With this reference point, the linkage disequilibrium in the Ashkenazi
Jewish population was interpreted as "matches signs of interbreeding or
'admixture' between Middle Eastern and European populations". In their
press release, Bray stated: "We were surprised to find evidence that
Ashkenazi Jews have higher heterozygosity
than Europeans, contradicting the widely-held presumption that they
have been a largely isolated group". "Thus, the AJ population shows
evidence of past founding events; however, admixture and selection have
also strongly influenced its current genetic makeup." The authors note
that their results will require further investigation.
|« August 2017 »|
| || ||1||2||3||4||5|