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

[Loki]

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

Abstract

Previous genetic studies have suggested a history of sub-Saharan African gene flow into some West Eurasian populations after the initial dispersal out of Africa that occurred at least 45,000 years ago. However, there has been no accurate characterization of the proportion of mixture, or of its date. We analyze genome-wide polymorphism data from about 40 West Eurasian groups to show that almost all Southern Europeans have inherited 1%–3% African ancestry with an average mixture date of around 55 generations ago, consistent with North African gene flow at the end of the Roman Empire and subsequent Arab migrations. Levantine groups harbor 4%–15% African ancestry with an average mixture date of about 32 generations ago, consistent with close political, economic, and cultural links with Egypt in the late middle ages. We also detect 3%–5% sub-Saharan African ancestry in all eight of the diverse Jewish populations that we analyzed. For the Jewish admixture, we obtain an average estimated date of about 72 generations. This may reflect descent of these groups from a common ancestral population that already had some African ancestry prior to the Jewish Diasporas.

Summary

Southern Europeans and Middle Eastern populations are known to have inherited a small percentage of their genetic material from recent sub-Saharan African migrations, but there has been no estimate of the exact proportion of this gene flow, or of its date. Here, we apply genomic methods to show that the proportion of African ancestry in many Southern European groups is 1%–3%, in Middle Eastern groups is 4%–15%, and in Jewish groups is 3%–5%. To estimate the dates when the mixture occurred, we develop a novel method that estimates the size of chromosomal segments of distinct ancestry in individuals of mixed ancestry. We verify using computer simulations that the method produces useful estimates of population mixture dates up to 300 generations in the past. By applying the method to West Eurasians, we show that the dates in Southern Europeans are consistent with events during the Roman Empire and subsequent Arab migrations. The dates in the Jewish groups are older, consistent with events in classical or biblical times that may have occurred in the shared history of Jewish populations.

[Grumpy Cat]

Very interesting but... I predict you're going to end up locking this thread.

[Peasant]

[Libertas]

All this may or may not be true but it is no reason to keep accepting increasing African or Asiatic influxes into any part of Europe.

[Lábaru]

all Southern Europeans have inherited 1%–3% African ancestry

Not bad considering the thousands of years of border, we, the Spanish North, did a perfect job., in a few of years the whole of Europe will be twenty times more African genes, and not exactly from bereberes

[Raikaswinþs]

one drop rules uh? lol looks like you´re in the mood for some bashing. I portrait you now yielding your sword and screaming "Bring them om , those greasy dagos, all at once !!! wrrouaarrg!!"" btw loki, everybody knows Bilbao, and not Londinium , is the centre of the universe. This map will explain it to ya

[Loki]

Polako blogged on it here:

Evidence of "recent" Sub-Saharan African admixture in Southern Europeans



Geographic gradient of African ancestry in Europeans. Sub-Saharan African ancestry proportions were estimated using f4 Ancestry Estimation. Populations in grey are estimated to have sub-Saharan African ancestry between 1–4%. The * in Switzerland indicates that the three populations available from this country have variable estimates: Swiss-Germans show no evidence of African mixture, Swiss-French 0.5±0.2% and Swiss-Italians 1.6±0.2%. The ‘+’ sign in Italy indicates that multiple samples were available but all show evidence of African mixture. No data are available from countries filled with diagonal lines.

[Foxy]

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?
An other thing that leaves me perplexed is the fact that these genes should be arrived in Southern Europe during the Roman Empire while Romans hadn't black slaves. Look better the Roman Empire extension:



Africa, for Romans, was modern Lybia and when they referred to "African slaves" they meant Berbers.
The only black slaves could be arrived from Southern Egypt but surely 99,9% of Romans slaves were from Europe, Northern Africa and Middle East and where sold in every part of the Empire including central Europe. So if the "responsible" of the arrival is really the Roman Empire,genetical borders cannot be so marked. Or the cause in an other one.

[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?
An other thing that leaves me perplexed is the fact that these genes should be arrived in Southern Europe during the Roman Empire while Romans hadn't black slaves. Look better the Roman Empire extension:

It's not me who did the study. And they didn't say "all", they said "almost all".

In any case, this is just for scientific interest. Those levels are negligible and unimportant.

[Agrippa]

Dienekes, quite eloquently and with excellent arguments, just ripped this study apart:

http://dienekes.blogspot.com/2011/04...-eurasian.html

This is truly a new age for this field of science, because for the first time, if you know your stuff, are intelligent enough, capable technically and invest sufficient time, you can refute in a very short period of time "studies" made by "scientists" - which were in the past very difficult to question by laymen.

I mean in physical anthropology for example, you could, with actual knowledge of a given people, refute a given theory someone came up with. Because it was verifiable with a limited amount of means. Same for many other sciences in question to a certain degree.

Now the new age of genetics just brought us the hot meal, we could either eat it or leave it, but we couldn't do too much about it, because the means were only available to a chosen few.

But with programs and data being available to more people and the growing general understanding of the principles behind this studies and scientific research, the official scientists can no longer deliver crappy studies and getting away with it, unless another scientists with these means might write a critical article about it some months later.

And this excellent piece of Dienekes just proves that, actually he makes these "scientists" look like amateurs.

Really great stuff, Dienekes developed into something great with his blog! up

Power to the people - in this field of science too - and no longer full dependence on crap produced by a few...