[Ombrageux]

First Europeans 'weathered Ice Age'


The genetic ancestry of the earliest Europeans survived the ferocious Ice Age that took hold after the continent was initially settled by modern people.

That is the suggestion of a study of DNA from a male hunter who lived in western Russia 36,000 years ago.

His genome is not exactly like those of people who lived in Europe just after the ice sheets melted 10,000 years ago.

But the study suggests the earliest Europeans did contribute their genes to later populations.

Europe was first settled around 40,000 years ago during a time known as the Upper Palaeolithic.

But conditions gradually deteriorated until ice covered much of the European landmass, reaching a peak 27,000 years ago.

The ice melted rapidly after 10,000 years ago, allowing populations from the south to re-populate northern Europe - during a time known as the Mesolithic. But the genetic relationships between pre- and post-Ice Age Europeans have been unclear.

Some researchers have in the past raised the possibility that pioneer populations in Europe could have gone extinct some time during the last Ice Age.

And one recent study looking at the skull features of ancient Europeans found that Upper Palaeolithic people were rather different from populations that lived during the later Mesolithic period.

In the latest study, an international team of researchers sequenced the genome (the genetic "blueprint" for a human) of a man buried in Kostenki, Russia.

They discovered a surprising genetic "unity" running from the first modern humans in Europe, through to later peoples. This, they claim, suggests that a "meta-population" of Palaeolithic hunter-gatherers managed to survive the Ice Age and colonise the landmass of Europe for more than 30,000 years.

"That there was continuity from the earliest Upper Palaeolithic to the Mesolithic, across a major glaciation, is a great insight into the evolutionary processes underlying human success," said co-author Dr Marta Mirazón Lahr, from Cambridge's Leverhulme Centre for Human Evolutionary Studies (LCHES).

"For 30,000 years ice sheets came and went, at one point covering two-thirds of Europe. Old cultures died and new ones emerged - such as the Aurignacian and the Gravettian - over thousands of years, and the hunter-gatherer populations ebbed and flowed.

"But we now know that no new sets of genes are coming in: these changes in survival and cultural kit are overlaid on the same biological background."

She added: "It is only when farmers from the Near East arrived about 8,000 years ago that the structure of the European population changed significantly."

The arrival of the first farmers transformed the genetic landscape of Europe - to the extent that no modern population is a good match for the Mesolithic Europeans encountered by the farmers as they spread out across the continent.

The farmers carried the signature of a cryptic population which split off very early from all other Eurasians, including early Europeans and East Asians, and survived in some unknown place until some of their descendants invented agriculture in the Middle East - carrying it into Europe after 8,000 years ago.

"This mystery population may have remained small for a very long time, surviving in refugia in areas such as the Zagros Mountains of Iran and Iraq, for example," said Dr Mirazón Lahr.

"We have no idea at the moment where they were for those first 30,000 years, only that they were in the Middle East by the end of the ice age, when they invented agriculture."

Intriguingly, the Kostenki man already shows some evidence of mixing with this very old population, which has been dubbed Basal Eurasians. But analysis of the Europeans who emerged from the Ice Age 10,000 years ago show little sign of this ancestral component in their genomes.

There is then some genetic continuity between modern-day Europeans and our ancestors who were tough, resourceful and sociable enough to survive the Ice Age. It’s quite inspiring: How many frozen, sunless winters did the Ancient Europeans survive so as to give birth to the next generation and pass on their unique heritage?

[Oxymoron]

More evidence of European supreme genes.

[mikema63]

How many frozen, sunless winters did the Ancient Europeans survive so as to give birth to the next generation and pass on their unique heritage?

The winters would have just as much sun then as now, it's not like the tilt of the earth was different during the Ice age.

Anyway, this is interesting from a historical standpoint, but it doesn't really mean much of anything genetically.

[Rich]

The winters would have just as much sun then as now, it's not like the tilt of the earth was different during the Ice age.

No it does vary, 8000 years ago the tilt was about three quarter of a degree larger. However I suspect this was more than counteracted by the lower humidity of the ice ages. There would have been substantially less cloud cover, so winters would have been less dark.

[ThirdTerm]

Kostenki XIV (Markina Gora), reconstructed by M. M. Gerasimov


Indian American actor Sendhil Ramamurthy, known for his roles in TV series like "Heroes" and "Psych".

According to a previous study by Krause et al. (2010), the Kostenki man belongs to Haplogroup U2 (mtDNA). U2 is most common in South Asia (6.5-20%) but it's very rare in the modern European populations (0.5-2%) and U2 has never been found in any Neolithic sites in Europe. This ancient Russian man had dark skin and brown eyes and the Kostenki individual may be more closely related to dark-skinned Indians than Scandinavians as he lacked typical European physical characteristics present in the U4 tribes. U2 people from South Asia roamed between Central Europe and Central Asia during the Paleolithic era and Kostenki 14 may possibly be misclassified as an early European man by overzealous researchers keen to prove modern-day Europeans' more ancient roots than previously thought. Haplogroup U4 is found at the highest frequency in the Indo-Aryan peoples of Pakistan and the Kalash people (34%) with blue eyes and fair skin and U4 is strongly associated with ancient European hunter-gatherers. Haplogroup U4 is found at high frequencies among remains from the Proto-Indo-European Corded Ware culture and Catacomb culture (25%) in the Bronze Age.

A recent ancient DNA study of Stone Age hunter-gatherers from central and eastern Europe has shown that most of the samples studied (>80%) shared mtDNA haplotypes belonging to haplogroups U5 and U4, haplogroups that notably are relatively rare in central Europe today [7]. Among them, sample 5830a from Hohlenstein-Stadel (Germany), defined as U5a2a, based on the HVS I sequence 16114A-16192-16256-16294-16311, was detected. Its closest HVS I relatives in modern populations can be found among eastern Europeans (in Latvians, Russians, Tatars and Mordvins). In the present study we have completely sequenced two U5a2a mitochondrial genomes with the characteristic transition at np 16311 in Russians (Figure S1). AMS radiocarbon dating of sample 5830a (at ~7.8 ky old) allows determination of a minimum age for the subcluster U5a2a to which it belongs. Phylogenetic analysis revealed that the coalescent ages of this subcluster vary from 5.7±1.2 ky (for a complete mtDNA clock rate) to 9.3±2.6 ky (for a synonymous clock rate). Therefore, the age of sample 5830a falls within the intervals of these molecular phylogenetic dating. We should note, however, that Russian U5a2a-16311 samples share a mutation at np 9293 with a Belorussian sample, thus forming a subcluster with the age of ~2.6 ky (Figure S1). Thus it is probable that similar HVS I sequences in Stone Age individuals and modern Russian individuals may be related only within the bounds of the whole subcluster U5a2a, defined, in fact, by parallel mutations at np 16311 originating independently. In addition, another ancient HVS I haplotype, 16192-16270, belonging probably to subcluster U5b1a, was found in skeletons dated to ~5.6 ky old, from Lithuania [7]. We have found that the age of ancient mtDNAs does not exceed the coalescence time estimates of modern U5b1a sequences, falling within the range of 9.3±3.5 ky (for a complete mtDNA clock rate) to 6.8±4.8 ky (for a synonymous clock rate) (Figure S2). In general, it seems that the combining of phylogenetic and archaeological approaches will be useful for cross-checking data and improvement of human mitochondrial molecular clock estimates, as new information about modern and ancient mitochondrial genomes becomes available [3].
http://www.plosone.org/article/info%3Ad ... ne.0010285