posted
This is another Brenna Henn et al article. xyyman posted some supplimental text from it on ESR but didn't have access to the main article. Does anybody have it?
I'm not sure what is here, Stonybrook website, public info:
Gene flow from North Africa contributes to differential human genetic diversity in southern Europe. 2013
Botigué LR, Henn BM, Gravel S, Maples BK, Gignoux CR, Corona E, Atzmon G, Burns E, Ostrer H, Flores C, Bertranpetit J, Comas D, Bustamante CD. Source Institut de Biologia Evolutiva, Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, 08003 Barcelona, Spain.
Abstract Human genetic diversity in southern Europe is higher than in other regions of the continent. This difference has been attributed to postglacial expansions, the demic diffusion of agriculture from the Near East, and gene flow from Africa. Using SNP data from 2,099 individuals in 43 populations, we show that estimates of recent shared ancestry between Europe and Africa are substantially increased when gene flow from North Africans, rather than Sub-Saharan Africans, is considered. The gradient of North African ancestry accounts for previous observations of low levels of sharing with Sub-Saharan Africa and is independent of recent gene flow from the Near East. The source of genetic diversity in southern Europe has important biomedical implications; we find that most disease risk alleles from genome-wide association studies follow expected patterns of divergence between Europe and North Africa, with the principal exception of multiple sclerosis.
Posts: 42939 | From: , | Registered: Jan 2010
| IP: Logged |
Human genetic differentiation across the Strait of Gibraltar Mathias Currat*, Estella S Poloni and Alicia Sanchez-Mazas*
Abstract Background The Strait of Gibraltar is a crucial area in the settlement history of modern humans because it represents a possible connection between Africa and Europe. So far, genetic data were inconclusive about the fact that this strait constitutes a barrier to gene flow, as previous results were highly variable depending on the genetic locus studied. The present study evaluates the impact of the Gibraltar region in reducing gene flow between populations from North-Western Africa and South-Western Europe, by comparing formally various genetic loci. First, we compute several statistics of population differentiation. Then, we use an original simulation approach in order to infer the most probable evolutionary scenario for the settlement of the area, taking into account the effects of both demography and natural selection at some loci.
Posts: 42939 | From: , | Registered: Jan 2010
| IP: Logged |
posted
I will bite on gibraltar
Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007
| IP: Logged |
posted
Sage. Did you read the abstract? Quote; " relatively high rate since preNeolithic times".
-------------------- Without data you are just another person with an opinion - Deming Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007
| IP: Logged |
quote:Originally posted by xyyman: Sage. Did you read the abstract? Quote; " relatively high rate since preNeolithic times".
Yes, that's interesting.
And then this:
quote: However, the remaining 35% of L mtDNAs form European-specific subclades, revealing that there was gene flow from sub-Saharan Africa toward Europe as early as 11,000 yr ago.
--María Cerezo (2013) Reconstructing ancient mitochondrial DNA links between Africa and Europe
Supplemental data from that study, by Brenna. Henn.
quote: Length of IBD Segments: We calculated a second statistic “LEA”, the average length of the segments shared IBD between a pair of individuals, one from European population and the other from North Africa | Sub-Saharan Africa. Normalization was based on the possible number of pairwise comparisons between both populations. LEA reflects the time since gene flow occurred in contrast to WEA (6). Interestingly, LEA shows an opposite pattern, northern and central European populations having higher values than southern ones (Fig. S17). This suggests that gene flow between southern Europe and North Africa is older than that in other regions in Europe, where longer (recent) segments are found.
While inferred IBD sharing does not indicate directionality, the North African samples that have highest IBD sharing with Iberian populations also tend to have the lowest proportion of the European cluster in ADMIXTURE (Fig. 1), e.g. Saharawi, Tunisian Berbers and South Moroccans. This suggests that gene flow occurred from Africa to Europe rather than the other way around.
--Brenna M. Henn Gene flow from North Africa contributes to differential human genetic diversity in southern Europe
quote:Originally posted by Troll Patrol aka Ish Gebor:
quote:Originally posted by xyyman: Sage. Did you read the abstract? Quote; " relatively high rate since preNeolithic times".
Yes, that's interesting.
And then this:
quote: However, the remaining 35% of L mtDNAs form European-specific subclades, revealing that there was gene flow from sub-Saharan Africa toward Europe as early as 11,000 yr ago.
--María Cerezo (2013) Reconstructing ancient mitochondrial DNA links between Africa and Europe
Supplemental data from that study, by Brenna. Henn.
quote: Length of IBD Segments: We calculated a second statistic “LEA”, the average length of the segments shared IBD between a pair of individuals, one from European population and the other from North Africa | Sub-Saharan Africa. Normalization was based on the possible number of pairwise comparisons between both populations. LEA reflects the time since gene flow occurred in contrast to WEA (6). Interestingly, LEA shows an opposite pattern, northern and central European populations having higher values than southern ones (Fig. S17). This suggests that gene flow between southern Europe and North Africa is older than that in other regions in Europe, where longer (recent) segments are found.
While inferred IBD sharing does not indicate directionality, the North African samples that have highest IBD sharing with Iberian populations also tend to have the lowest proportion of the European cluster in ADMIXTURE (Fig. 1), e.g. Saharawi, Tunisian Berbers and South Moroccans. This suggests that gene flow occurred from Africa to Europe rather than the other way around.
--Brenna M. Henn Gene flow from North Africa contributes to differential human genetic diversity in southern Europe
Nice post. I didn't read the new Henn or the Cerezo study yet, but your quotes, along with the Frigi study points out to a very ancient so-called sub-Saharan presence in North Africa. In general, there seem to be very ancient and more recent gene flows in both directions between the Africa and Europe. Something we know or we are hint at by numerous other studies, of course.
Some of those Africans (probably at a bit later date) left some rock art such has these in the Atlas Mountains in the Morocco country (discovered by Susan Searight). So very close to one of the region with very ancient gene flows between Africa and Europe (Iberian peninsula).
Supplemental data from that study, by Brenna. Henn.
quote: Length of IBD Segments: We calculated a second statistic “LEA”, the average length of the segments shared IBD between a pair of individuals, one from European population and the other from North Africa | Sub-Saharan Africa. Normalization was based on the possible number of pairwise comparisons between both populations. LEA reflects the time since gene flow occurred in contrast to WEA (6). Interestingly, LEA shows an opposite pattern, northern and central European populations having higher values than southern ones (Fig. S17). This suggests that gene flow between southern Europe and North Africa is older than that in other regions in Europe, where longer (recent) segments are found.
While inferred IBD sharing does not indicate directionality, the North African samples that have highest IBD sharing with Iberian populations also tend to have the lowest proportion of the European cluster in ADMIXTURE (Fig. 1), e.g. Saharawi, Tunisian Berbers and South Moroccans. This suggests that gene flow occurred from Africa to Europe rather than the other way around.
--Brenna M. Henn Gene flow from North Africa contributes to differential human genetic diversity in southern Europe
^^^ This is not a comment comprehensive to gene flow between North Africa to Southern Europe. It is describing a gene flow from North Africa to Southern Europe. It is in the context of bi-directional gene flow both ways including back migration from Europe into Africa noted by the same author Brenna Henn Genomic Ancestry of North Africans Supports Back-to-Africa Migrations Brenna Henn eta al 2012
The relevant issue is how much and when. I can't comment because I don't have access to this new 2013 paper
Posts: 42939 | From: , | Registered: Jan 2010
| IP: Logged |
posted
^ the comment in the supplement is about Identity by descent.
And why is it in context of last years paper, of a "bi-directional gene flow? Based on what was there a no-directional gene flow? Again, where is the physical anthropological evidence?
Then you go, "I don't have access to this paper"?
Weird to say at least.
Key: Canis - Canary Islands; And - Andalusia; Gal - Galicia; Bas - Basques; Spa - Spain; Por - Portugal; Fra - France; Ita - Italy; Tsi - Tuscany; Gre - Greece ; ItaJ - Italian Jews; AshJ - Ashkenazi Jews; Qat - Qatar; NMor - North Morocco; SMor - South Morocco; OccS - Saharawi; Alg - Algeria; Tun - Tunisia; Lib - Libya; Egy - Egypt; Yri - Yoruba from Nigeria; Mkk - Maasai from Kenya.
Posts: 22235 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010
| IP: Logged |
quote:Originally posted by Troll Patrol aka Ish Gebor: Based on what was there a no-directional gene flow? Again, where is the physical anthropological evidence?
I don't know what a "no directional gene flow is" I didn't use that term
quote:Originally posted by Troll Patrol aka Ish Gebor:
Then you go, "I don't have access to this paper"?
Weird to say at least.
what's weird about it? You know what I mean, I don't feel like paying to read it right now. xyyman hasn't read it and neither have you, I'm not talking about the suppliment.
Gene flow from North Africa contributes to differential human genetic diversity in southern Europe.
There was gene flow out of and into N Africa from Europe. The into was talked about in last years article and his article talks about the out of. As stated IBD does not indicate direction
Stop playing games, this paper is not a refutation of last years paper
Posts: 42939 | From: , | Registered: Jan 2010
| IP: Logged |
posted
information overload...but thanks for the PM link. Need to process it all.
-------------------- Without data you are just another person with an opinion - Deming Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007
| IP: Logged |
quote:Originally posted by Troll Patrol aka Ish Gebor: Based on what was there a no-directional gene flow? Again, where is the physical anthropological evidence?
I don't know what a "no directional gene flow is" I didn't use that term
quote:Originally posted by Troll Patrol aka Ish Gebor:
Then you go, "I don't have access to this paper"?
Weird to say at least.
what's weird about it? You know what I mean, I don't feel like paying to read it right now. xyyman hasn't read it and neither have you, I'm not talking about the suppliment.
Gene flow from North Africa contributes to differential human genetic diversity in southern Europe.
There was gene flow out of and into N Africa from Europe. The into was talked about in last years article and his article talks about the out of. As stated IBD does not indicate direction
Stop playing games, this paper is not a refutation of last years paper
My bad, it was a typo.
Based on what was there a bi-directional gene flow? Again, where is the physical anthropological evidence?
Repost,
And why is it in context of last years paper, of a "bi-directional gene flow? Based on what was there a bi-directional gene flow? Again, where is the physical anthropological evidence?
The weird thing again is, your claiming what the paper is suppose to be and not suppose to be. But you haven't read it, correct? lol
Awkward is yesterday you asked me, from what study that supplemental data came. Today I again have to explain like I did yesterday, that it's from the same paper, as if you did not know it, already. And you conveniently left it out in your original post in this thread, as if it doesn't exist.
The one who needs to stop playing games is you.
Posts: 22235 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010
| IP: Logged |
quote:Originally posted by xyyman: information overload...but thanks for the PM link. Need to process it all.
It's not a overload, it's a summery and canalization of detailed information. To show a logical pattern. Else it would have taken way too long to get to the same point.
I see it kinda' as writing an algorithm.
Posts: 22235 | From: האם אינכם כילדי הכרית אלי בני ישראל | Registered: Nov 2010
| IP: Logged |
posted
Henn is like an old hen always clucking about inconsequentials. Point is that this matter has been settled a while back by haplogroup and MtDNA analysis. Africa-specific L3, M, and N are found in East and North Africa following the same pattern as E1b1b--the male haplogroup. Point is: wherever the male haplogroup travels the corresponding female haplogroup follows--notwithstanding kidnapping, female war captives, slave purchases[as in North Africa], adding to the gene pool mix.
Posts: 5492 | Registered: Nov 2004
| IP: Logged |
posted
Niiicee!!! What paper is the SNP Chart from? I can't recall this from the Henn or Behar paper? Indeed the Great Lakes seem to be the source for all SNPs. The SNP data parallels mtdna-M1, and ydna E1b1*
quote:Originally posted by Troll Patrol aka Ish Gebor: ^ the comment in the supplement is about Identity by descent.
And why is it in context of last years paper, of a "bi-directional gene flow? Based on what was there a no-directional gene flow? Again, where is the physical anthropological evidence?
Then you go, "I don't have access to this paper"?
Weird to say at least.
Key: Canis - Canary Islands; And - Andalusia; Gal - Galicia; Bas - Basques; Spa - Spain; Por - Portugal; Fra - France; Ita - Italy; Tsi - Tuscany; Gre - Greece ; ItaJ - Italian Jews; AshJ - Ashkenazi Jews; Qat - Qatar; NMor - North Morocco; SMor - South Morocco; OccS - Saharawi; Alg - Algeria; Tun - Tunisia; Lib - Libya; Egy - Egypt; Yri - Yoruba from Nigeria; Mkk - Maasai from Kenya.
Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007
| IP: Logged |
Tukuler
multidisciplinary Black Scholar
Member # 19944
posted
quote:Originally posted by xyyman:
Sage. Did you read the abstract? Quote; " relatively high rate since preNeolithic times".
Naw man, I'm bummed out since my stg drv crapped out and I lost all the genetic reports I'd saved up since joining ES.
So I sit and stew 'cos I cain't cross reference or compare old against new reports.
@!*&%
Anyway I called the Amazigh activist and NorthAfrocentric geneticists over inner African DNA in pre-historic Europe while they claim no inner Africans in pre-historic Africa Minor and like I said before you are dead on the money about no ice blocking Iberia <=> Maghreb passage during the GM hence no need to wait 'till PGM for population interaction.
Posts: 8179 | From: the Tekrur straddling Senegal & Mauritania | Registered: Dec 2011
| IP: Logged |
quote:Originally posted by the lioness,: [QB] This is another Brenna Henn et al article. xyyman posted some supplimental text from it on ESR but didn't have access to the main article. Does anybody have it?
I'm not sure what is here, Stonybrook website, public info:
UBBFriend: Email this page to someone!
Printer-friendly view of this topic