Here we successfully sequenced 67 complete mitochondrial DNA genomes of 5200 to 300-year-old humans from the plateau. Apart from identifying two ancient plateau lineages (haplogroups D4j1b and M9a1a1c1b1a) that suggest some ancestors of Tibetans came from low-altitude areas 4750 to 2775 years ago and that some were involved in an expansion of people moving between high-altitude areas 2125 to 1100 years ago, we found limited evidence of recent matrilineal continuity on the plateau.
Congratulations to the authors. I enjoyed this paper and hope they have more in the works.
Skipping past some of the technical discussion, let’s get down to the nitty-gritty of what it all means:
The haplogroup networks and haplotype–haplogroup sharing demonstrated to us that there was partial matrilineal continuity in Tibetans from 5200 years ago.
That means modern-day Tibetans descended from a mix of peoples, some of whom have been there for over 5,000 years, and some of whom arrived recently.
Under this continuity, some people spread from low-to-high altitudes 4750 to 2775 years ago and some expanded within high-altitude areas 2125 years ago. The timing revolved around the high-altitude agriculture transformed by barley, which appeared 5.2 ka near the northeastern edge of the plateau and moved into high altitudes by 3.6 ka .
Farmers. I wonder how difficult it was to get barley to grow up there. Tibet seems like a pretty harsh environment.
However, based on the 16 haplogroups that have a frequency in Tibetans (a subset of 21 unique haplogroups), D4j1b and M9a1a1c1b1a would represent about 13% (2 out of 6) as the footprint of that event. Thus, our findings did not favour a substantial migration of lowland farmers to the high-altitude areas.
So, farmers did expand into Tibet, but not a ton of farmers (or at least, not a ton of farming women.) Probably because Tibet is a really harsh place–both for people and barley strains that aren’t adapted to living there.
An explanation for the surplus of unaccounted maternal lineages could be that there were earlier waves of populations who settled into higher altitudes and underwent isolation by distance . The earlier settlers were potentially hunters and gatherers who left behind no human fossils, perhaps connected to the blade tool assemblages or fossilized handprints and footprints dating to as far back as 40–30 ka  or 13–7 ka . Our results could support a recent diffusion of plateau populations into an otherwise stable population continuous with previous high-altitude populations. A similar point of view has been made from analysing the whole genomes of present-day Tibetans .
What would being a hunter gatherer in Tibet have been like?
I figured there was probably some ancient population that has contributed to the modern Tibetan population both because of the aforementioned environmental difficulties, and also because the Tibetans show adaptations to the area, which take time to accumulate. Among those adaptations, Tibetans have some DNA they appear to have picked up from the Denisovans, and Denisovans probably haven’t lived in Tibet in a very, very long time.
I’ve long wondered which group arrived first in Europe: the Indo-Europeans or the Finno-Ugrics. Most Europeans speak one of the hundreds of languages in the Indo-European family tree, but a few groups speak languages from the mostly Siberian Finno-Ugric branch of the Uralic family.
(Sorry, guys, I’m out of practice writing and these sentences don’t sound good to me, but the only way to improve is to forge ahead, so let’s go.)
Major countries/ethnic groups that speak Finno-Ugric languages include the Finns (obviously,) Saami/Lapps, Hungarians, and Estonians. The most southerly of this family, Hungarian, arrived in the Carpathian Basin within the span of recorded History (in 894 or 895, followed by a few years of warfare to secure their territory,) but the origins of the other European Finno-Ugric languages remains mysterious.
Who arrived first, the Indo Europeans or the Finns? Did the Saami always live in their current homelands, or did they once range much further south or east? Did they migrate here recently or long ago (since the entire area was under ice sheets during the ice age, no one lived there tens of thousands of years ago.)
With the exception of Hungarian, these languages all hail from the far north (especially if you include the Samoyidic languages, which hail from north of Komi on the map,) a cold and forbidding land where herding, hunting, gathering, and fishing have remained the primary way of life until quite recently–the long winters making agriculture very difficult.
Here we analyse ancient genomic data from 11 individuals from Finland and north-western Russia. We show that the genetic makeup of northern Europe was shaped by migrations from Siberia that began at least 3500 years ago. This Siberian ancestry was subsequently admixed into many modern populations in the region, particularly into populations speaking Uralic languages today. Additionally, we show that ancestors of modern Saami inhabited a larger territory during the Iron Age, which adds to the historical and linguistic information about the population history of Finland.
Let’s cut to the pictures, because they are worth a thousand words:
Just in case you are unclear on the geography, the Modern Saami come from northern part of the Finnoscandian peninsula. Six of the ancient remains came from Bolshoy Oleni Ostrov in the Murmansk Region on the Kola Peninsula–that’s the topmost dot on the map, now in Russia. These remains are very old–dated to about 1610-1436 BC.
Seven remains came from Levänluhta in Isokyrö, Finland, from a more recent burial dated to around 300-800 AD. (Actually, I think Levanluhta is a lake, so This is the most southwestern burial on the map, in an area where the modern Finns live.
And the remains of two people came from a much more recent Saami cemetery in the Kola peninsula, Chalmny Varre, dating from the 17 or 1800s.
All of this DNA was compared against a variety of reference populations:
(I would just like to pause for a moment to appreciate both the beauty and hard work that went into these graphs.)
PC2 graphs are a little complicated, but what we’re basically looking at (in color) are two different human population axes. They very roughly correlate to north-south (up and down) and east-west, (left to right), because people tend to be more closely related to their neighbors than people thousands of miles away, but there’s another, more fascinating story going on here.
On the right-hand side, we have a cline that maps very nicely to north and south, from the Yukagir–a people from a part of Russia that’s so far to the northeast it’s almost in Alaska–at the top and the Semende of Indonesia and the Atayal, an indigenous Taiwanese group, at the bottom. (Most Taiwanese you meet are either newly arrived Han Chinese or older Han Chinese; the aboriginal Taiwanese are different, but likely the ancestors of Polynesians.)
Most east Asian DNA shows up as a blend of these two groups (which we may call roughly polar and tropical). In the chart to the right, taken from Haak et al, the polar DNA is red and the tropical is yellow. So the up-down cline on the right side of the map represents which particular mix of Polar/Tropical DNA these folks have.
On the left side of the graph, we have a farming/hunter-gatherer cline. The first farmers hailed from Anatolia (now Turkey, but that was before the Turks moved to Turkey,) and subsequently spread/conquered most of Europe and probably a few other places, because agriculture was quite successful. So the orange is Middle Easterners; above them are southern Europeans like Albanians and Basques; then the English, French, Hungarians, Finns, etc; and finally some older burials of people with descriptive names like “Eastern Hunter-Gatherer” [EHG] or “Scandinavian Hunter-gatherers” [SHG].
(I have to constantly remind myself what these little abbreviations mean, but The Genetic Prehistory of the Baltic Region probably clears things up a bit:
Similarly, in the Eastern Baltic, where foraging continued to be the main form of subsistence until at least 4000 calBCE15, ceramics technology was adopted before agriculture, as seen in the Narva Culture and Combed Ceramic Culture (CCC). Recent genome-wide data of Baltic pottery-producing hunter-gatherers revealed genetic continuity with the preceding Mesolithic inhabitants of the same region as well as influence from the more northern EHG21,22, but did not reveal conclusively whether there was a temporal, geographical or cultural correlation with the affinity to either WHG or EHG.
The transition from the Late (Final) Neolithic to the Early Bronze Age (LNBA) is seen as a major transformative period in European prehistory, accompanied by changes in burial customs, technology and mode of subsistence as well as the creation of new cross-continental networks of contact seen in the emergence of the pan-European Corded Ware Complex (CWC, ca. 2900–2300 calBCE) in Central2 and north-eastern Europe21.
If you remember your Guns, Germs, and Steel, Turkish farmers had a really hard time getting their wheat to grow up in really cold places like Northern Russia, Scandinavia and Narva (near the border between Estonia and Russia on the Baltic Sea,) which is why modern Finland is super poor and Turkey and Mexico, where corn was domesticated, are rich–what it doesn’t quite work like that?
So most Europeans today are a mix of Anatolian farmers and various European hunter gatherer groups, with exactly how much you got depending a lot on whether the local environment was hospitable to farming. The pure hunter-gatherer genomes therefore show up as “further north” than the mixed, modern genomes of modern French and British folks.
There were additional events besides the Anatolian conquest that shaped modern European genetics–mostly the aforementioned Indo-European conquest–but the Indo-Europeans were at least part hunter-gatherer by DNA (nomadic pastoralists by profession,) so on this scale, their contributions look a lot like the older hunter-gatherer DNA.
So the interesting part of the graph is the middle, where all of the central Eurasian peoples are plotted. The purple band is various Finno-Ugric/Uralic speakers.
Hungarians are solidly in Europe because the ancient conquering Magyars left behind their language, but not much of their DNA (as we’ve discussed previously.) The Nganasan are one of the most thoroughly Siberian peoples you can imagine; they historically survived by hunting reindeer.
The green swaths (light and dark teal) are mostly Turkic-language speaking peoples; the Turkic peoples originated near Mongolia/Korea and spread out from there, mostly absorbing the DNA of whomever they encountered and passing on their language. The authors have also included Mongolian (which is not in the Turkic language family) in the light green group and some Caucuses groups in the dark teal.
Interestingly, the Yukaghir language (far upper right) is (according to Wikipedia,) potentially in the greater Finno-Ugric/Uralic family:
The relationship of the Yukaghir languages with other language families is uncertain, though it has been suggested that they are distantly related to the Uralic languages, thus forming the putative Uralic–Yukaghir language family.
Based on the genetics, I’d say it looks very likely that the ancestors of Uralic-speaking Nganasan and the Yukagirs were conversing in some sort of mutually intelligible language. Unfortunately, Yukaghir has very few speakers and is likely to die, so there’s not much time to research it.
Finally in the Light Teal we have some groups from Pakistan/Afghanistan, like the Balochi.
(Note that all of the colors used in these studies are arbitrary; DNA doesn’t really have a color.)
So where do our ancient DNA remains fall on this graph?
Today, the Levanluhta site is in Finland, surrounded solidly by Finns (and maybe some random Scandinavians; who knows;) in 300-800 AD, the population was almost identical to modern Saami. So even though Saami and Finns both speak Finno-Ugric languages, the Finns replaces the Saami in this area sometime in the past 1,500 years or so.
One Levanlughta skeleton is an exception–the one marked Levanlughta_B; it is clearly closer to the Finns and English on this graph, but deeper mathematical analysis disputes this conclusion:
One of the individuals from Levänluhta (JK2065/Levänluhta_B) rejects a cladal position with modern Saami to the exclusion of most modern Eurasian populations. This individual also rejects a cladal position with Finns. We analysed low coverage genomes from four additional individuals of the Levänluhta site using PCA (Supplementary Figure 3), confirming the exclusive position of Levänluhta_B compared to all other six individuals (including the four low-coverage individuals) from that site, as is consistent with the ADMIXTURE and qpAdm results. The outlier position of this individual cannot be explained by modern contamination, since it passed several tests for authentication (see Methods) along with all other ancient individuals. However, no direct dating was available for the Levänluhta material, and we cannot exclude the possibility of a temporal gap between this individual and the other individuals from that site.
In other words, it is a mystery.
The remains from Chalmny Varre, which we know was a Saami cemetery, unsurprisingly cluster with the other Saami.
The Bolshoy remains, though, are quite interesting. They are shifted slightly in the direction of the ancient hunter-gatherers (perhaps their descendants, if still around, have mixed a bit with the agriculturalists.) Their physical location is about as far east as the Red Squares (ethnic Russians,) yet the more closely resemble the Mansi or the Selkups. (The modern Mansi live here; the modern Selkups live nearby.)
Getting down to the bar graphs, we see this data presented in a different way.
There are three groups that we can see contributing to most modern Europeans–Farmers, represented by the Orange LBK DNA; exclusively Indo-European, Green, notably not found in the Basque; and hunter-gatherers in Dark Blue. (Note that the ancestors of the Indo-Europeans hailed from the Central Eurasian steppes and so their DNA could have gotten around there, too.)
The modern Saami also have a Purple component to their DNA, which finds its highest expression in the Nganasan of far eastern polar Russia.
So the oldest burials–the Bolshoy–show no agricultural DNA. They are hunter-gatherers+Siberians, with a touch of Indo-European (probably from a steppe population that might have contributed to the Indos as well) and a bit they share with… the Karitiana of Brazil? Well, the Native Americans did descend from Paleo Siberians, so some genetic relatedness is expected.
The more recent burials, which cluster with the modern Saami, all show agricultural DNA–probably due to marrying a few of the local Finns/Russians who carry some agricultural DNA (who are almost genetically identical on this scale) rather than a pure LBK agriculturalist.
Here we see why the one outlier, Levanlughta_B, doens’t group with the Finns, either–modern Finns and Russians have some of that Nganasan-style Siberian DNA (probably from the same process that gifted Finnish/Russian DNA to the Saami), but Levanlughta_B doesn’t. Levanlughta_B looks more like the Baltic BA sample (Baltic Bronze Age.) Perhaps this individual was just a merchant, traveler, or lost–or represents a stage before the modern Finnish population had been produced.
The Finnish population itself is interesting, because it is genetically very similar to the Russian, but obviously speaks a language far more closely related to Saami (Lapp) than anything in the Indo-European tree. While it is therefore likely that the Finns replaced the Saami in the area around Lake Levanlughta, it seems also probable that in the process, they absorbed a large number of Uralic-speaking people. Who conquered (or married) whom? Did an ancient Balto-Slavic population move into what is now Finland, marry the local Saami girls, and adopt their language? Did an ancient Siberian population speaking a Uralic language conquer some ancient group of Russians, take their women, pass on their Uralic language, and later move into Finland and drive out the locals? Or perhaps something even more complicated occurred.
As for the Bolshoy, are they related (closely) to the modern Saami, or are they a group that simply died out?
The paper goes on:
While the Siberian genetic component presented here [Purple] has been previously described in modern-day populations from the region1,3,9,10, we gain further insights into its temporal depth. Our data suggest that this fourth genetic component found in modern-day north-eastern Europeans arrived in the area before 3500 yBP. It was introduced in the population ancestral to Bolshoy Oleni Ostrov individuals 4000 years ago at latest, as illustrated by ALDER dating using the ancient genome-wide data from the Bolshoy samples. The upper bound for the introduction of this component is harder to estimate. The component is absent in the Karelian hunter-gatherers (EHG)3 dated to 8300–7200 yBP as well as Mesolithic and Neolithic populations from the Baltics from 8300 yBP and 7100–5000 yBP respectively8.
Karelia is a region that crosses the border between Finland and Russia, so it is significant that this Siberian component isn’t found in ancient Karelian hunter-gatherers. Of course, the Siberians could have just been further north, however, the authors note that we have archaeological evidence of the spread of the Bolshoy people:
The large Nganasan-related component in the Bolshoy individuals from the Kola Peninsula provides the earliest direct genetic evidence for an eastern migration into this region. Such contact is well documented in archaeology, with the introduction of asbestos-mixed Lovozero ceramics during the second millennium BC50, and the spread of even-based arrowheads in Lapland from 1900 BCE51,52. Additionally, the nearest counterparts of Vardøy ceramics, appearing in the area around 1,600-1,300 BCE, can be found on the Taymyr peninsula, much further to the East51,52. Finally, the Imiyakhtakhskaya culture from Yakutia spread to the Kola Peninsula during the same period24,53. Contacts between Siberia and Europe are also recognised in linguistics. The fact that the Nganasan-related genetic component is consistently shared among Uralic-speaking populations, with the exceptions of absence in Hungarians and presence in the non-Uralic speaking Russians, makes it tempting to equate this genetic component with the spread of Uralic languages in the area.
The authors qualify this with a bit of “it’s complicated; people move around a lot,” but basically it’s People: not pots.
That was an enjoyable read; I look forward to the next paper from these folks.
Scientists have long believed that the first humans made it to the Americas by crossing from now-Russia to now-Alaska. When and how they did it–by boat or by foot–remain matters of contentious debate. Did people move quickly through Alaska and into the rest of North America, or did they hover–as the “Bering standstill” hypothesis suggests–in Beringia (or the Aleutian Islands) for thousands of years?
Archaeologists working at the Upward Sun River site (approximately in the middle of Alaska) recently uncovered the burials of three children: a cremated three year old, and beneath it, a 6-12 week old infant and a 30 week, possibly premature or stillborn fetus. The three year old has been dubbed “Upward Sun River Mouth Child,” and the 6 week old “Sun-Rise Girl Child.” Since these aren’t really names, I’m going to dub them Sunny (3 yrs old), Rosy (6 weeks), and Hope (fetus).
They died around 11,500 years ago, making them the oldest burials so far from northern North America. Rosy and Hope were probably girls; cremation rendered Sunny’s gender a mystery. Rosy and Hope were covered in red ocher and buried together, accompanied by four decorated antler rods, two dart points and two stone axes. (Here’s an illustration of their burial.) The site where the children were buried was abandoned soon after Sunny’s death–perhaps their parents were too sad to stay, or perhaps the location was just too harsh.
Rosy and Hope were well enough preserved to yield DNA.
Surprisingly, they weren’t sisters. Rosy’s mother’s mtDNA hailed from haplogroup C1b, which is found only in the Americas (though its ancestral clade, haplogroup C, is found throughout Siberia.) Hope’s mtDNA is from haplogroup B2, which is also only found in the Americas. Oddly, B2’s parent clade, (B), isn’t common in Siberia–it’s much more common in places like Vietnam, Laos, the Philippines, and Saipan. It’s not entirely absent from Siberia, but it got to Alaska without leaving a larger trail remains a mystery.
Since they are found in the Americans but not Asia, we know these lineages most likely evolved over here; the main questions are when and where. If the Bering Standstill hypothesis is correct and the Indians spent 10-20,000 years stranded in Beringia, they would have had plenty of time to evolve new lineages while still in Alaska. By contrast, if they crossed relatively quickly and then dispersed, these new lineages would have had much less time to emerge, and we would expect them to show up as people moved south.
Or there could have been multiple migration waves, with different haplogroups arriving in different waves. (There were multiple migration waves, but the others occurred well after Sunny and the others were buried.)
In fact, there are five mtDNA lineages found only in the Americas (A2, B2, C1, D1, and X2a.) With Hope and Rosy, we have now identified all five mtDNA lineages in North American burials over 8,000 years old, lending support to the Beringian Standstill hypothesis.
But were the Upward Sun River children’s families ancestral to today’s Native Americans? Not quite.
It looks like Sunny’s tribe split off from the rest of the Beringians (or perhaps the others split off from them) around 22-18,000 years ago. Most of the others headed south, while Sunny’s people stayed in Alaska and disappeared (perhaps because all of their children died.) So Sunny’s tribe was less “grandparent” to today’s Indians and more “great aunt and uncle,” but they still hailed from the same, even older ancestors who first set out from Siberia.
I have previously favored the Aleutian or at least a much more rapid Beringian route, but it looks like I was wrong. I find the idea of the Bering Standstill difficult to believe, but that may just be my own biases. Perhaps people really did get stuck there for thousands of years, waiting for the ice to clear. What amazing people they must have been to survive for so long in so harsh an environment.