Population Genetics of the Ashkenazim

Abstract

The Ashkenazim are a well‐studied population with a dynamic and unique history. The spread of Jewish populations from the Middle East to locations in the Diaspora in the past 2000 years represents a microcosm of the evolutionary processes affecting modern humans as they dispersed out of Africa (e.g. founder effects, migrations, admixture and adaptation). Ashkenazim – Jews who trace their ancestry to founders who moved to the Rhine Valley in the fourth century – are no exception. Recent studies both support and refute long‐standing hypotheses of Ashkenazi origins. Together, the results Strengthen the inferences that Ashkenazi Jews trace their ancestry to a genetically diverse population in the Middle East that underwent a series of founder events – reducing genetic diversity relative to the ancestral population – and that subsequently experienced significant gene flow during the period of Ashkenazi residency in Europe.

Key Concepts

  • Ashkenazi Jews are genetically more similar to each other than to individuals from other populations.
  • Ashkenazi Jews are most closely related to other Jewish populations.
  • The Ashkenazim likely arose from a genetically diverse population in the Middle East.
  • Ashkenazi Jews appear equally close to both Middle Eastern and European populations.
  • Ashkenazi Jews are not closely related to modern populations that best represent the Khazars.
  • Ashkenazi Jews likely received 30–60% gene flow from Europeans.
  • Ashkenazi Jews likely underwent multiple extreme events of population size reduction and expansion.
  • About half of the genomic regions under putative selection in the Ashkenazim are not found to be under selection in Europeans.
  • Most Ashkenazi disease loci are not under strong positive selection.

Keywords: Ashkenazim; population genetics; genomics; demography; SNP array; admixture; founder effect; selection

Figure 1. Four possible models of AJ origins. Model (a) depicts a complete Middle Eastern origin with no gene flow from Europeans, with multiple population reductions and expansions. Model (b) depicts a partial Middle Eastern origin with gene flow from Europeans, and multiple population reductions and expansions. Model (c) model depicts a complete European or Turkic origin, with no ancestry from the Middle East. The time points a, b and c indicate the Out of Middle East (100–80 generations ago), out of Rome (70–50 generations ago) and eastern expansion (40–20 generations ago) events, respectively.
Figure 2. Population structure inferred by ADMIXTURE analysis. ADMIXTURE plots at K = 10. Each individual is represented by a vertical stacked column of genetic membership proportions. The Jewish groups are highlighted in red. Western Ashkenazi Jews: France, Germany and the Netherlands; Central and Eastern Ashkenazi Jews: Austria, Belorussia, Hungary, Latvia, Lithuania, Poland, Romania and Russia. Reproduced from Behar et al.2013 © Digital Commons @Wayne State University.
Figure 3. PCA of common variants in Ashkenazim (AJ), non‐AJ Jewish, European and Middle Eastern populations. Reproduced with permission from Carmi et al.2014 © Nature Publishing Group.
Figure 4. A diagram of a two‐population demographic model with Ashkenazim and Flemish. The diagram shows the reconstruction of the ancient history by fitting the joint allele frequency spectrum using dadi and using a mutation rate of 1.44 × 10−8 per generation per bp, and recent AJ history by fitting the IBD length decay pattern. The wide arrow represents an admixture event; all effective population sizes (horizontal arrows) are in number of diploid individuals; all times were computed assuming 25 years per generation. Adapted and reproduced with permission from Carmi et al.2014 © Nature Publishing Group.
Figure 5. The distribution, over all pairs of individuals, of the fraction of the genome shared IBD (segment lengths >3 cM) within AJ, within Flemish (FL) or between AJ and FL. Adapted and reproduced with permission from Carmi et al.2014 © Nature Publishing Group.
close

References

Atzmon G , Hao L , Pe'er I , et al. (2010) Abraham's children in the genome era: major Jewish diaspora populations comprise distinct genetic clusters with shared Middle Eastern ancestry. American Journal of Human Genetics 86: 850–859.

Bonne‐Tamir B , Karlin S and Kenett R (1979) Analysis of genetic data on Jewish populations: I. Historical background, demographic features, and genetic markers. American Journal of Human Genetics 31: 324–340.

Behar DM , Garrigan D , Kaplan ME , et al. (2004) Contrasting patterns of Y chromosome variation in Ashkenazi Jewish and host non‐Jewish European populations. Human Genetics 114: 354–365.

Behar DM , Metspalu E , Kivisild T , et al. (2006) The matrilineal ancestry of Ashkenazi Jewry: portrait of a recent founder event. American Journal of Human Genetics 78 (3): 487–497.

Behar DM , Yunusbayev B , Metspalu M , et al. (2010) The genome‐wide structure of the Jewish people. Nature 466: 238–243.

Behar DM , Metspalu M , Baran Y , et al. (2013) No evidence from genome‐wide data of a Khazar origin for the Ashkenazi Jews. Human Biology 85: 859–900.

Bray SM , Mulle JG , Dodd AF , et al. (2010) Signatures of founder effects, admixture, and selection in the Ashkenazi Jewish population. Proceedings of the National Academy of Sciences of the United States of America 107 (37): 16222–16227.

Brook KA (2006) The Jews of Khazaria. New York: Rowman & Littlefield Publishers, Inc.

Carmi S , Palamara PF , Vacic V , et al. (2013) The variance if identity‐by‐descent sharing in the Wright‐Fisher model. Genetics 193: 911–928.

Carmi S , Hui KY , Kochav E , et al. (2014) Sequencing an Ashkenazi reference panel supports population‐targeted personal genomics and illuminates Jewish and European origins. Nature Communications 5: 4835.

Carmelli D and Cavalli‐Sforza LL (1979) The genetic origin of the Jews: a multivariate approach. Human Biology 51: 41–61.

Cochran G , Hardy J and Harpending H (2006) Natural history of Ashkenazi intelligence. Journal of Biosocial Science 38: 659–693.

DellaPergola S (2001) Some fundamentals in Jewish demographic history. In: DellaPergola S and Even S (eds) Papers in Jewish Demography 1997, pp. 11–33. Jerusalem: The Hebrew University of Jerusalem.

Faber A (1987) A tangled web: whole Hebrew and Ashkenazic origins. Language & Communication 7: 15–22.

Fearman M (2008) Population genetics of the Ashkenazim. In: Encyclopedia of Life Sciences (ELS). Chichester: John Wiley & Sons, Ltd. DOI: 10.1002/9780470015902.a0020818.

Frisch A , Colombo R , Michaelovshky E , et al. (2004) Origin and spread of the 1278insTATC mutation causing Tay‐Sachs disease in Ashkenazi Jews: genetic drift as a robust and parsimonious hypothesis. Human Genetics 114: 366–376.

Goldstein DB , Reich DE , Bradman N , et al. (1999) Age estimates of two common mutations causing factor XI deficiency: recent genetic drift is not necessary for elevated disease incidence among Ashkenazi Jews. American Journal of Human Genetics 64: 1071–1075.

Gross SJ , Pletcher BA , Monaghan KG , et al. (2008) Carrier screening in individuals of Ashkenazi Jewish descent. Genetic in Medicine 10: 54–56.

Guha S , Rosenfeld JA , Malhotra AK , et al. (2012) Implications for health and disease in the genetic signature of the Ashkenazi Jewish population. Genome Biology 13: R2.

Gusev A , Palamara PF , Aponte G , et al. (2012) The architecture of long‐range haplotypes shared within and across populations. Molecular Biology and Evolution 29 (2): 473–486.

Hammer MF , Redd AJ , Wood ET , et al. (2000) Jewish and Middle Eastern non‐Jewish populations share a common pool of Y‐chromosome biallelic haplotypes. Proceedings of the National Academy of Sciences of the United States of America 97: 6769–6774.

Kopelman NM , Stone L , Wang C , et al. (2009) Genomic microsatellites identify shared Jewish ancestry intermediate between Middle Eastern and European populations. BMC Genetics 10: 80.

Mendes‐Flohr P and Reinhartz J (2010) Demography of modern Jewish history. In: Mendes-Flohr P and Reinharz J (eds). The Jew in the Modern World: A Documentary History, 3rd edn, appendix, New York: Oxford University Press. pp. 879–892.

Morton NE , Kenett R , Yee S , et al. (1982) Bioassay of kinship in populations of Middle Eastern origin and controls. Current Anthropology 23: 157–166.

Motulsky AG (1980) Ashkenazi Jewish gene pools: admixture, drift and selection. In: Eriksson AW et al. (eds) Population Structure and Disorders, pp. 353–365. New York: Academic Press.

Motulsky AG (1995) Jewish diseases and origins. Nature Genetics 9: 99–101.

Nebel A , Filon D , Brinkmann B , et al. (2001) The Y chromosome pool of Jews as part of the genetic landscape of the Middle East. American Journal of Human Genetics 69: 1095–1112.

Need A , Kasperaviciute D , Cirulli ET and Goldstein DB (2009) A genome‐wide genetic signature of Jewish ancestry perfectly separates individuals with and without full Jewish ancestry in a large random sample of European Americans. Genome Biology 10: R7.

Niell BL , Long JC , Rennert G , et al. (2003) Genetic anthropology of the colorectal cancer–susceptibility allele APC I1307K: evidence of genetic drift within the Ashkenazim. American Journal of Human Genetics 73 (6): 1250–1260.

Olshen AB , Gold B , Lohmueller KE , et al. (2008) Analysis of genetic variation in Ashkenazi Jews by high density SNP genotyping. BMC Genetics 9: 14.

Ostrer H (2001) A genetic profile of contemporary Jewish populations. Nature Reviews Genetics 2: 891–898.

Palamara PF , Lencz T , Darvasi A , et al. (2012) Length distributions of identity by descent reveal fine‐scale demographic history. American Journal of Human Genetics 91: 1–15.

Risch N , de Leon D , Ozelius L , et al. (1995) Genetic analysis of idiopathic torsion dystonia in Ashkenazi Jews and their recent descent from a small founder population. Nature Genetics 9: 152–159.

Risch N , Tang H , Katzenstein H , et al. (2003) Geographic distribution of disease mutations in the Ashkenazi Jewish population supports genetic drift over selection. American Journal of Human Genetics 72 (4): 812–822.

Slatkin M (2004) A populations‐genetic test of founder effects and implications for Ashkenazi Jewish diseases. American Journal of Human Genetics 75: 282–293.

Zlotogora J , Zeigler M and Bach G (1988) Selection in favor of lysosomal storage disorders? American Journal of Human Genetics 42: 271–273.

Further Reading

Entine J (2007) Abraham's Children: Race, Identity, and the DNA of the Chosen People. New York: Grand Central Publishing.

Jacobs NA (2005) Yiddish: A Linguistic Introduction. New York: Cambridge University Press.

Ostrer H (2012a) The population genetics of the Jewish people. Human Genetics. DOI: 10.1007/s00439-012-1235-6.

Ostrer H (2012b) Legacy: A Genetic History of the Jewish People. New York: Oxford University Press, Inc.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Gladstein, Ariella, and Hammer, Michael F(Mar 2016) Population Genetics of the Ashkenazim. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0020818.pub2]