The History of African Gene Flow into Southern Europeans, Levantines, and Jews

[Ibericus]

But this study is only K=3 (sub-saharan, Utah-whites and Chinese) which means the sub-saharan component includes other stuff, at least in Caucasians (mid-east, east-afr, north-afr, etc). In a K=11 like that of Dienekes the spaniards have only 0.1% sub-saharan, which is the same as that of British. Or the K=14 of Rhazib with 0% sub-saharan or the K=8 of Eurogenes with also 0%.

[Agrippa]

But this study is only K=3 (sub-saharan, Utah-whites and Chinese) which means the sub-saharan component includes other stuff, at least in Caucasians (mid-east, east-afr, north-afr, etc). In a K=11 like that of Dienekes the spaniards have only 0.1% sub-saharan, which is the same as that of British. Or the K=14 of Harappa project with 0% sub-saharan.

Obviously most of the "African admixture" in Europeans is Caucasoid from white Africa and semi-Caucasoid from East Africa, such numbers for RECENT WEST AFRICAN admixture are ridiculous.

[Rouxinol]

This is manipulation for their own interests. Thousands of scientific papers are biased by their authors' beliefs or intentions - this one would be no surprise. Now look at some of the members of the research team:

http://genepath.med.harvard.edu/~reich/Reich_People.htm

What would one expect from this? They're doing their job to undermine European preservation thought as saying "you have to accept massive immigration into your countries because you have this or that".

[Loki]

I am sorry Loki, you can't post a text where you say that ALL the Southern Europeans have more than 1% of African genes and then a scheme that says that in Sardinians and Northern Italians African genes are 0,2% and in Southern Italy and Spain a mere 1%. The only one that seems to have a relevant African admixture (more than 1%) is Portugal and Greece is not considered. Where is Greece?

Polako claims that ALL Italians have SSA admixture.

http://www.forumbiodiversity.com/sho...&postcount=154

All Italians have some Sub-Saharan African admixture, including Swiss Italians. So if you're Sicilian, I wouldn't even have to scan more than a couple of chromosomes. It really wouldn't be any trouble.

It's not an insult or anything, just of historical interest. Nothing "wrong" about it.

[Grumpy Cat]

I'm pretty sure the SSA admixture is either noise, or perhaps a genetic similarity. There may be some admixture, but I doubt it's in ALL people.

A disease found in Southern Europeans and Levantines (not sure about Jews), thalassemia, is very similar to sickle cell, and maybe a similar gene is responsible, and shows up as an SSA marker on genetic tests.

But bringing up Levantines, I read that SSA gene flow comes from ports in the Levant being important in the Trans-Saharan slave trade. Again, though, I don't think would be in all people from that region. Frequency would probably be quite small.

[Agrippa]

I'm pretty sure the SSA admixture is either noise, or perhaps a genetic similarity. There may be some admixture, but I doubt it's in ALL people.

A disease found in Southern Europeans and Levantines (not sure about Jews), thalassemia, is very similar to sickle cell, and maybe a similar gene is responsible, and shows up as an SSA marker on genetic tests.

But bringing up Levantines, I read that SSA gene flow comes from ports in the Levant being important in the Trans-Saharan slave trade. Again, though, I don't think would be in all people from that region. Frequency would probably be quite small.

Also that's related to what I'm always saying, namely that genflow and genetic drift are two things, but selection is another.

It is quite obvious that certain blood traits were selected positive for example in Malaria regions, if that happened, you can no longer use it as a marker to estimate the original admixture, EVEN IF the trait was introduced by genflow from population X.

That is why f.e. Mongoliform traits can be also more common among certain populations than their Mongoloid percentage is and lower in others, depending on the selective pressures working for or against them.

If people ignore selection in these respects - same with bloodgroups - their conclusions must be faulty.

Yet it is perfectly possible and an objective scientific question to analyse how much of an admixture or tendency towards this or that population has.

But IN THIS CASE the methodology is the problem, not just some potential ideological influences which might be there or not - after all scientists too are just humans and they might make mistakes not willingly, but just because they had the wrong idea.

And it seems to me, that this is the case with this study and only the authority of it being produced by "official scientists" gives it some rest of credibility in the face of the facts.

[Raikaswinþs]

Well, we Iberians are a race of our own, only related to some peoples of southern france and to other spaniards or mixed spaniards in diaspora. That is something we know and are familiar with. "Spain is different" (that applies to our Iberian brothers the portuguese too) We don´t even look truly similar to other meds in the way germanic peoples or some slavic peoples do to each othe (I mean, as a whole, of course there are cases in which a Spaniard has Italian looks and vice'versa) . And I don´t think that an 1% of possible SSA admixcture is the answer to that clear difference. We have more than 1% of norther european admixture and yet we don´t look like germans. Even the blond and red haired spaniards are distinctively Iberian in appearance. There´s more Iberian blood and lineages in North Africa than viceversa

[Arch Hades]

The study said the Greeks didn't have any admixture and they were outliers on the PCA, or that they threw a wrench in the whole thing and thus discarded them i guess.

"We curated these data using Principal Components Analysis (PCA) [16] (Table S2), with the most important steps being: (i)Removal of 140 individuals as outliers who did not cluster with the bulk of samples of the same group, (ii) Removal of all 8 Greek samples as they separated into sub-clusters in PCA so that it was not clear which of these clusters was most representative, (iii)."

Another thing of note is it is Interesting that the STRUCTURE results came up with some pretty significant differences between their 'new methods'. In the study, the STRUCTURE results had the Sardinians and Northern Italians only 0.2% admixed while using their 'other method' they came out 2.9% admixed...so it's probably best to go with STRUCTURE results for all groups IMO. This type of discrepancy wasn't in other samples like the Palestinians, who are known to have Negroid/Sub Saharan admixture.

But another flaw of this study is the sample sets, they got it from the PORPES database and much of the database got their samples from diaspora populations and almost half of the samples did not have the origin of any grandparents observed.



So anyway, not very conclusive IMO.

[Prince Carlo]

I am sorry Loki, you can't post a text where you say that ALL the Southern Europeans have more than 1% of African genes and then a scheme that says that in Sardinians and Northern Italians African genes are 0,2% and in Southern Italy and Spain a mere 1%. The only one that seems to have a relevant African admixture (more than 1%) is Portugal and Greece is not considered. Where is Greece?

No way non Sicilian S.Italians have 1% of african admixture. On Dodecad/Eurogenes we have around 0.5%(most of which is semi-caucasoid East African).

[Contra Mundum]

About the same percentage as Neanderthal ancestry.