Results 1 to 7 of 7

Thread: Analysis of Ashkenazi Jewish Genomes

  1. #1
    Member

    Join Date
    Aug 2007
    Last Online
    Saturday, February 8th, 2020 @ 03:48 AM
    Ethnicity
    Katarinensische
    Subrace
    Dinarid
    Gender
    Age
    44
    Family
    Single adult
    Posts
    1,243
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    4
    Thanked in
    4 Posts

    Post Ashkenazi Jewish Population

    Geographic Distribution of Disease Mutations in the Ashkenazi Jewish Population Supports Genetic Drift over Selection

    Neil Risch,1,3 Hua Tang,2 Howard Katzenstein,4 and Josef Ekstein4

    Departments of 1Genetics and 2Statistics, Stanford University, Standford, CA; 3Division of Research, Kaiser Permanente, Oakland, CA; and 4Dor Yeshorim, Brooklyn, NY

    Received October 9, 2002; accepted for publication December 30, 2002; electronically published February 24, 2003.

    The presence of four lysosomal storage diseases (LSDs) at increased frequency in the Ashkenazi Jewish population has suggested to many the operation of natural selection (carrier advantage) as the driving force. We compare LSDs and nonlysosomal storage diseases (NLSDs) in terms of the number of mutations, allele-frequency distributions, and estimated coalescence dates of mutations. We also provide new data on the European geographic distribution, in the Ashkenazi population, of seven LSD and seven NLSD mutations. No differences in any of the distributions were observed between LSDs and NLSDs. Furthermore, no regular pattern of geographic distribution was observed for LSD versus NLSD mutationswith some being more common in central Europe and others being more common in eastern Europe, within each group. The most striking disparate pattern was the geographic distribution of the two primary Tay-Sachs disease mutations, with the first being more common in central Europe (and likely older) and the second being exclusive to eastern Europe (primarily Lithuania and Russia) (and likely much younger). The latter demonstrates a pattern similar to two other recently arisen Lithuanian mutations, those for torsion dystonia and familial hypercholesterolemia. These observations provide compelling support for random genetic drift (chance founder effects, one 11 centuries ago that affected all Ashkenazim and another 5 centuries ago that affected Lithuanians), rather than selection, as the primary determinant of disease mutations in the Ashkenazi population

  2. #2
    Senior Member
    Vetinari's Avatar
    Join Date
    Oct 2003
    Last Online
    Friday, June 15th, 2012 @ 04:40 AM
    Subrace
    Other
    Country
    United States United States
    Gender
    Politics
    Nationalist
    Religion
    Lovecraftian
    Posts
    244
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    1
    Thanked in
    1 Post

  3. #3
    Senior Member

    Join Date
    Dec 2003
    Last Online
    Thursday, February 26th, 2009 @ 10:52 PM
    Ethnicity
    German
    Subrace
    Nordid
    Country
    Prussia Prussia
    Gender
    Posts
    162
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    1
    Thanked in
    1 Post

    Post Re: Ashkenazi Jewish Population

    Ashkenazi?

    Why everybody hate jews? ASK A NAZI!

  4. #4
    Senior Member

    Join Date
    Jun 2010
    Last Online
    Friday, May 6th, 2011 @ 07:10 AM
    Ethnicity
    Norwegian English and Swedish
    Ancestry
    Nowegian English father ,Swedish mother
    Subrace
    Nordid
    Country
    United Kingdom United Kingdom
    Location
    Valhalla
    Gender
    Family
    In a steady relationship
    Posts
    172
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Post Analysis of Ashkenazi Jewish Genomes

    ScienceDaily (Aug. 26, 2010) — Through genomic analysis, researchers at Emory University School of Medicine have shown that the Ashkenazi Jewish population is genetically more diverse than people of European descent, despite previous assumptions that Ashkenazi Jews have been an isolated population.

    http://www.sciencedaily.com/releases...cience+News%29

  5. #5
    Senior Member
    Ediruc's Avatar
    Join Date
    Nov 2009
    Last Online
    4 Weeks Ago @ 08:58 AM
    Status
    Available
    Ethnicity
    German-American
    Ancestry
    German-American and proud
    Subrace
    Alpinid-Nordid
    Country
    United States United States
    Gender
    Posts
    1,301
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    41
    Thanked in
    28 Posts
    This shouldn't really be much of a surprise

  6. #6
    Waffenbrüder und Blut
    „Friend of Germanics”
    Funding Membership Inactive
    Rassenhygieniker's Avatar
    Join Date
    Apr 2009
    Last Online
    @
    Ethnicity
    Homo europæus
    Ancestry
    Iutum (Jutes), Agendicum (Sénons)
    Subrace
    Atlantid
    Country
    United Kingdom United Kingdom
    Location
    Scotland
    Gender
    Family
    Single adult
    Politics
    NS-Eugeniker
    Religion
    Highland Catholic
    Posts
    725
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    12
    Thanked in
    12 Posts
    Old news, Germanics have been saying that jews are nothing but a bunch of tribal mongrels for millennia.

  7. #7
    Senior Member
    Roderic's Avatar
    Join Date
    Feb 2010
    Last Online
    Monday, May 27th, 2019 @ 05:09 AM
    Ethnicity
    German
    Gender
    Posts
    643
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    12
    Thanked in
    11 Posts

    Analysis of Ashkenazi Jewish Genomes

    Signatures of founder effects, admixture, and selection in the Ashkenazi Jewish population

    The Ashkenazi Jewish (AJ) population has long been viewed as a genetic isolate, yet it is still unclear how population bottlenecks, admixture, or positive selection contribute to its genetic structure. Here we analyzed a large AJ cohort and found higher linkage disequilibrium (LD) and identity-by-descent relative to Europeans, as expected for an isolate.

    However, paradoxically we also found higher genetic diversity, a sign of an older or more admixed population but not of a long-term isolate. Recent reports have reaffirmed that the AJ population has a common Middle Eastern origin with other Jewish Diaspora populations, but also suggest that the AJ population, compared with other Jews, has had the most European admixture. Our analysis indeed revealed higher European admixture than predicted from previous Y-chromosome analyses. Moreover, we also show that admixture directly correlates with high LD, suggesting that admixture has increased both genetic diversity and LD in the AJ population.

    Additionally, we applied extended haplotype tests to determine whether positive selection can account for the level of AJ-prevalent diseases. We identified genomic regions under selection that account for lactose and alcohol tolerance, and although we found evidence for positive selection at some AJ-prevalent disease loci, the higher incidence of the majority of these diseases is likely the result of genetic drift following a bottleneck. Thus, the AJ population shows evidence of past founding events; however, admixture and selection have also strongly influenced its current genetic makeup.

    http://www.pnas.org/content/early/20...81107.abstract



    "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," says first author Steven Bray, PhD, a postdoctoral fellow in Warren's laboratory.

    ...

    High linkage disequilibrium can come either from an isolated population (for example, an island whose residents are all descendents of shipwreck survivors) or the relatively recent mixture of separate populations. Bray and his colleagues did find evidence of elevated linkage disequilibrium in the Ashkenazi Jewish population, but were able to show that this matches signs of interbreeding or "admixture" between Middle Eastern and European populations.

    The researchers were able to estimate that between 35 and 55 percent of the modern Ashkenazi genome comes from European descent.

    "Our study represents the largest cohort of Ashkenazi Jews examined to date with such a high density of genetic markers, and our estimate of admixture is considerably higher than previous estimates that used the Y chromosome to calculate European admixture at between five and 23 percent," Bray says.

    ...

    "Only six of the 21 disease genes that we examined showed evidence of selection," Bray says. "This supports the argument that most of the Ashkenazi-prevalent diseases are not generally being selected for, but instead are likely a result of a genetic bottleneck effect, followed by random drift."
    The new paper comes in the heels of two other papers by Behar et al. and Atzmon et al. which considered Jews in general, discovering additional clusters of Jews that were distinct from Ashkenazi Jews.

    As I have argued in my review of these papers, the different clusters are not the result of isolation, as the different groups of Jews do not only deviate from each other, but also in the direction of their host populations. It would be worthwhile to perform similar admixture analyses on non-AJ populations to determine what their influence from host populations is. With a little effort it would be possible to reconstruct the ancestral Jewish population, by identifying what is common in the different Jewish populations.




    From the paper:
    The fixation index, FST, calculated concurrently to the PCA, confirms that there is a closer relationship between the AJ and several European populations (Tuscans, Italians, and French) than between the AJ and Middle Eastern populations (Fig. S2B). This finding can be visualized with a phylogenetic tree built using the FST data (Fig. S2C), showing that the AJ population branches with the Europeans and not Middle Easterners. Two recent studies performing PCA and population clustering with high-density SNP genotyping from many Jewish Diaspora populations, both showed that of the Jewish populations, the Ashkenazi consistently cluster closest to Europeans (13, 25).

    Genetic distances calculated by both groups also show that the Ashkenazi are more closely related to some host Europeans than to the ancestral Levant (13, 25). Although the proximity of the AJ and Italian populations could be explained by their admixture prior to the Ashkenazi settlement in Central Europe (13), it should be noted that different demographic models may potentially yield similar principal component projections (33); thus, it is also consistent that the projection of the AJ populations is primarily the outcome of admixture with Central and Eastern European hosts that coincidentally shift them closer to Italians along principle component axes relative to Middle Easterners. Taken as a whole, our results, along with those from previous studies, support the model of a Middle Eastern origin of the AJ population followed by subsequent admixture with host Europeans or populations more similar to Europeans. Our data further imply that modern Ashkenazi Jews are perhaps even more similar with Europeans than Middle Easterners.
    The bolded part reminds me of what I wrote in my review of Atzmon et al. regarding the choice of parental populations and how they affect admixture estimates.

    The "Middle Eastern" component estimate will increase if central and eastern Europeans are used as representative of the European admixture, while the "European" estimate will increase if Italians are used. But, the same applies to the other end of the continuum: if ancestral Jews were indeed like current Middle Easterners such as the Druze or Palestinians, but the latter may have moved (in genetic space) away from ancient Levantines due to subsequent admixture (Arabs, and in the case of Palestinians even Africans): this would reduce the inferred Middle Eastern component.

    Estimating admixture percentages in the absence of clear knowledge about parental populations is no easy thing, but the intermediate-leaning-on-Europe status of AJ relative to living Europeans and living Middle Easterners seems to be a pretty secure conclusion.

    http://dienekes.blogspot.com/2010/08...h-genomes.html
    "Tolerance and apathy are the last virtues of a dying society."

    ~Aristotle

Similar Threads

  1. Ancient-human Genomes Plucked from Cave Dirt
    By Ringenwald in forum Anthropogeny & Ethnogenesis
    Replies: 0
    Last Post: Sunday, May 7th, 2017, 09:09 AM
  2. Replies: 0
    Last Post: Thursday, July 21st, 2016, 04:04 PM
  3. Jewish Intolerance - Analysis of this Attitude
    By IlluSionSxxx in forum Cultural & Linguistic Anthropology
    Replies: 0
    Last Post: Tuesday, October 30th, 2007, 12:40 AM
  4. The Scientific Basis for Race (Metric on the Space of Genomes)
    By Enlil in forum Bio-Anthropology & Human Variation
    Replies: 4
    Last Post: Tuesday, January 16th, 2007, 04:13 AM
  5. Ribeiro's typology, genomes, and Spanish colonialism
    By Euclides in forum Population Genetics
    Replies: 1
    Last Post: Wednesday, June 2nd, 2004, 01:21 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •