Mortimer
10-05-2014, 02:22 AM
In a second ABC also based on pairwise comparisons, we used the Bulgarian Romani as a proxy to locate the putative source population of the European Romani within the Indian subcontinent (see Figures S3E and S3F). The genetically similar [24] Indo-European speaking groups from north-west India (Meghawal in Rajasthan) and northern India (Kashmiri Pandit in Jammu and Kashmir), were the populations showing the largest number of comparisons with a Bayes factor of >1.5 (94% each; see Figure 4A and Table S1). Despite a lack of samples from that area, the highlighted geographic region in India as the source area for the Romani encloses the Punjab, as suggested previously by anthropological, linguistic [2], and mitochondrial DNA (mtDNA) [8] evidence.
http://origin-ars.els-cdn.com/content/image/1-s2.0-S0960982212012602-gr4.jpg
inally, in a third ABC using Meghawal Indians as a proxy for the parental Romani population and Bulgarian and Spanish Romani as proxies for eastern and western European Romani groups, respectively (see Figure S3G), we aimed to estimate the parameters of the Romani demographic history (see Figure 4B; see Figure S3H and Table S2 for centrality and dispersion statistics). The date of the out-of-India founder event was estimated at ∼1.5 thousand years ago (kya). After a strong bottleneck, the proto-Romani effective population size became 47% of the parental Indian population. During the migration toward Europe, the Romani would have undergone modest genetic admixture with the populations encountered, including Middle East, Caucasus and Central Asia (number of migrants per generation estimated to be ∼2.2% of the proto-Romani population size during 13 generations, or ∼330 years). Around 0.9 kya, the eastern and western European Romani would have diverged. The western European Romani would have undergone an additional bottleneck reducing their population size to 70% of that of eastern European Romani. Finally, both western and eastern European Romani would have admixed with non-Romani European populations (∼4% and ∼5% of migrants per generation; during ∼38 generations or ∼940 years). In sum, the increasing genetic distance from the Balkans and the decaying effective population sizes in western Romani point at cumulative drift events within Europe as one of the main forces driving the extensive genetic differentiation observed within the European Romani, regardless of their recent common origin.
http://www.sciencedirect.com/science/article/pii/S0960982212012602
what is a strong genetic bottleneck which reduced the romani ancestral genetic component, is that the same as admixture or something else? thanks. i think romani can be seen as indian outliers. also many would pass in india. western european romani not so much i think, they share closer ties to europeans and look less indian (wouldnt pass in india). so i would differentiate between western european romani and eastern european romani, first closer to europe second closer to india.
http://origin-ars.els-cdn.com/content/image/1-s2.0-S0960982212012602-gr2.jpg
also romani not that much mixed as people believe
We then analyzed the length of the genomic segments of non-Romani European origin. Strikingly, several Romani populations from Central Europe (Slovakia, Hungary, and Romania) and from the Balkan area (Bulgaria and Croatia) show low mean values of genetic admixture, but a few individuals present very long segments of non-Romani origin (Figures S4F and S4G). This would suggest a recent and ongoing shift in the social rules of the acceptance of Romani and non-Romani couples within Romani groups. Conversely, European Romani from Lithuania, Portugal, and Spain show higher non-Romani European admixture but in shorter chromosomal tracks. This is suggestive of older patterns of genetic admixture and implies higher levels of recent genetic isolation from non-Romani Europeans in these countries. Alternatively, mixed couples may leave the Romani communities and integrate into the non-Romani societies, and thus would not be sampled from Romani groups in these countries.
http://origin-ars.els-cdn.com/content/image/1-s2.0-S0960982212012602-gr4.jpg
inally, in a third ABC using Meghawal Indians as a proxy for the parental Romani population and Bulgarian and Spanish Romani as proxies for eastern and western European Romani groups, respectively (see Figure S3G), we aimed to estimate the parameters of the Romani demographic history (see Figure 4B; see Figure S3H and Table S2 for centrality and dispersion statistics). The date of the out-of-India founder event was estimated at ∼1.5 thousand years ago (kya). After a strong bottleneck, the proto-Romani effective population size became 47% of the parental Indian population. During the migration toward Europe, the Romani would have undergone modest genetic admixture with the populations encountered, including Middle East, Caucasus and Central Asia (number of migrants per generation estimated to be ∼2.2% of the proto-Romani population size during 13 generations, or ∼330 years). Around 0.9 kya, the eastern and western European Romani would have diverged. The western European Romani would have undergone an additional bottleneck reducing their population size to 70% of that of eastern European Romani. Finally, both western and eastern European Romani would have admixed with non-Romani European populations (∼4% and ∼5% of migrants per generation; during ∼38 generations or ∼940 years). In sum, the increasing genetic distance from the Balkans and the decaying effective population sizes in western Romani point at cumulative drift events within Europe as one of the main forces driving the extensive genetic differentiation observed within the European Romani, regardless of their recent common origin.
http://www.sciencedirect.com/science/article/pii/S0960982212012602
what is a strong genetic bottleneck which reduced the romani ancestral genetic component, is that the same as admixture or something else? thanks. i think romani can be seen as indian outliers. also many would pass in india. western european romani not so much i think, they share closer ties to europeans and look less indian (wouldnt pass in india). so i would differentiate between western european romani and eastern european romani, first closer to europe second closer to india.
http://origin-ars.els-cdn.com/content/image/1-s2.0-S0960982212012602-gr2.jpg
also romani not that much mixed as people believe
We then analyzed the length of the genomic segments of non-Romani European origin. Strikingly, several Romani populations from Central Europe (Slovakia, Hungary, and Romania) and from the Balkan area (Bulgaria and Croatia) show low mean values of genetic admixture, but a few individuals present very long segments of non-Romani origin (Figures S4F and S4G). This would suggest a recent and ongoing shift in the social rules of the acceptance of Romani and non-Romani couples within Romani groups. Conversely, European Romani from Lithuania, Portugal, and Spain show higher non-Romani European admixture but in shorter chromosomal tracks. This is suggestive of older patterns of genetic admixture and implies higher levels of recent genetic isolation from non-Romani Europeans in these countries. Alternatively, mixed couples may leave the Romani communities and integrate into the non-Romani societies, and thus would not be sampled from Romani groups in these countries.