Ancient genome from Africa sequenced for the first time

Very interesting news from the world of population genetics, researchers have found the gentic evidence for a migration of Eurasians back into the horn of africa 3000 years ago.

The first ancient human genome from Africa to be sequenced has revealed that a wave of migration back into Africa from Western Eurasia around 3,000 years ago was up to twice as significant as previously thought, and affected the genetic make-up of populations across the entire African continent.
The genome was taken from the skull of a man buried face-down 4,500 years ago in a cave called Mota in the highlands of Ethiopia -- a cave cool and dry enough to preserve his DNA for thousands of years. Previously, ancient genome analysis has been limited to samples from northern and arctic regions

This particular migration has been alluded to in a couple papers over the last couple of years, but this new study seems to pin it down.
And the genome of the person they sampled predates that migration by 1500 years.

By comparing the ancient genome to DNA from modern Africans, the team have been able to show that not only do East African populations today have as much as 25% Eurasian ancestry from this event, but that African populations in all corners of the continent -- from the far West to the South -- have at least 5% of their genome traceable to the Eurasian migration

This might help explain how even the San have minute traces of Denisovan and Neanderthal ancestry, even though they have been isolated to africa for the last 40k years.

The cause of the West Eurasian migration back into Africa is currently a mystery, with no obvious climatic reasons. Archaeological evidence does, however, show the migration coincided with the arrival of Near Eastern crops into East Africa such as wheat and barley, suggesting the migrants helped develop new forms of agriculture in the region.

Geopolitical instability in the aftermath of the later bronze age collapse, and the rise of new political institutions in the near east around this time would be my guess of a cuase in absence of climatic causes.

While the genetic make-up of the Near East has changed completely over the last few thousand years, the closest modern equivalents to these Neolithic migrants are Sardinians, probably because Sardinia is an isolated island, says Jones. "The famers found their way to Sardinia and created a bit of a time capsule. Sardinian ancestry is closest to the ancient Near East."
"Genomes from this migration seeped right across the continent, way beyond East Africa, from the Yoruba on the western coast to the Mbuti in the heart of the Congo -- who show as much as 7% and 6% of their genomes respectively to be West Eurasian," said Marcos Gallego Llorente, first author of the study, also from Cambridge's Zoology Department.
"Africa is a total melting pot. We know that the last 3,000 years saw a complete scrambling of population genetics in Africa. So being able to get a snapshot from before these migration events occurred is a big step," Gallego Llorente said.

Once again the sardinians show up as a "prototype" for early eurasians.
And I think it safe to say that the bantu expansion had a role in spreading this gene set throughout africa, as the authors imply.

Ancient genome from Africa sequenced for the first time

originally posted by: punkinworks10
Once again the sardinians show up as a "prototype" for early eurasians.
And I think it safe to say that the bantu expansion had a role in spreading this gene set throughout africa, as the authors imply.

Ancient genome from Africa sequenced for the first time

Cause of Sardinia's isolated gene pool and a migration into Africa...

www.theguardian.com...



Maybe

originally posted by: Anaana

originally posted by: punkinworks10
Once again the sardinians show up as a "prototype" for early eurasians.
And I think it safe to say that the bantu expansion had a role in spreading this gene set throughout africa, as the authors imply.

Ancient genome from Africa sequenced for the first time

Cause of Sardinia's isolated gene pool and a migration into Africa...

www.theguardian.com...

Maybe

Like I said

Geopolitical instability in the aftermath of the later bronze age collapse, and the rise of new political institutions in the near east around this time would be my guess of a cause in absence of climatic causes.

a reply to: Anaana
P.S.
thanks for the link a good read.

Since they mention Etruscans,
from Dienekes Blog

The whereabouts of the homeland or homelands of the so-called Sea Peoples have been endlessly debated. This article re-examines this problem by looking at one of the ‘Eteocretan’ inscriptions from the town of Praisos. It is argued that this text is written in an Indo-European language belonging to the OscanUmbrian branch of the Italic language family. Based on this finding it is suggested that this language must have arrived in eastern Crete during the Late Bronze Age, when Mycenaean rulers recruited groups of mercenaries from Sicily, Sardinia and various parts of the Italian peninsula. When the Mycenaean state system collapsed around 1200 BC, some of these groups moved to the northern Aegean, to Cyprus and to the coastal districts of the Levant. It is also suggested that this reconstruction explains the presence of an Etruscan-speaking community in sixth-century-BC Lemnos. An interesting corollary of this theory is that the Sea Peoples were present in the Mycenaean world some considerable time before its collapse in the early twelfth century

dienekes.blogspot.com...

and link to original pdf
www.talanta.nl...

Very interesting.

I like the idea of the Sardinians being the first Euroasians.

a reply to: Astrocyte
Sorry , but the sardinians are not the first Eurasians,
but they are a remanant of an early Anatolian population . They are nearly a million years removed from the first Eurasians, Georgian Homo Erectus.

The saying what goes around comes around is apt here folks left Africa and returned home and left again the history of migrations is fascinating, in one of my threads I made mention of the Natufians who had Nile valley connections with a culture called Mushabian and went north into the Levant where they hooked up with others in Anatolia to become the first Farmers.

a reply to: Spider879
Hi spider,
One aspect I find most fascinating is the temporal relationship between this Eurasian migration from the north and east, and the Bantu expansion from the west. Its perfectly timed

That makes me tend to think both of these major migrations were climate related.

originally posted by: punkinworks10
a reply to: Spider879
Hi spider,
One aspect I find most fascinating is the temporal relationship between this Eurasian migration from the north and east, and the Bantu expansion from the west. Its perfectly timed

That makes me tend to think both of these major migrations were climate related.

You know I hadn't really thought about a climatic angle I had always figured the Bantu migrations were just population explosion/expansions with the acquirement of iron, that angle bears looking into.
On a side note the Syrian mass migration into Europe is ultimately tied to climatic change today but that issue is better debated and talked about on another forum..

a reply to: Spider879
This data in this paper, when combined with the findings of a couple of other papers , raises some questions.

First off, the San have been a genetically distinct group for nearly 40k years.
Secondly the San also have extremely low levels of neandethal and denisovan ancestry.
Given that , the original Eurasian admixture event had to have happened at least 40kya, that implies that the denisovan input has to be before that, to give ample time for a back migration, Asia , where denisovans have been found.

Hi guys this is an update someone hipped me to, in the article it seem the Eurasian dna in Africa was not as wide spread as once thought.
Error Found in Study of First Ancient African Genome

Andrea Manica, a population geneticist at the University of Cambridge, UK, who co-led the study, says the team made a mistake in its conclusion that the backflow reached western and central Africa. “The movement 3,000 years ago, or thereabouts, was limited to eastern Africa,” he says.
Incompatible software
Manica says that the error occurred when his team compared genetic variants in the ancient Ethiopian man with those in the reference human genome. Incompatibility between the two software packages used caused some variants that the Ethiopian man shared with Europeans (whose DNA forms a large chunk of the human reference sequence) to be removed from the analysis. This made Mota man seem less closely related to modern European populations than he actually was—and in turn made contemporary African populations appear more closely related to Europeans. The researchers did have a script that they could have run to harmonize the two software packages, says Manica, but someone forgot to run it.
www.scientificamerican.com...

a reply to: Spider879

Software incompatibility, isn't that always the case?



Nice job...and also a nice reminder that "truth" is constantly changing, and persistently fluid.

originally posted by: Anaana
a reply to: Spider879

Software incompatibility, isn't that always the case?

Nice job...and also a nice reminder that "truth" is constantly changing, and persistently fluid.

Yeah science is great like that though , it makes it difficult to rest easily on one's laurels, egos be damned, hooray for the scientific process where long held or new truths can be challenged ..