Category: Historical Population Genetics

Y chromosomes around the Baltic

Posted on by Razib Khan

A new paper on rare Y chromosomal lineages around the Baltic, Phylogenetic history of patrilineages rare in northern and eastern Europe from large-scale re-sequencing of human Y-chromosomes:

…a considerable number of men in every population carry rare paternal lineages with estimated frequencies around 5%…Here we harness the power of massive re-sequencing of human Y chromosomes to identify previously unknown population-specific clusters among rare paternal lineages in NEE. We construct dated phylogenies for haplogroups E2-M215, J2-M172, G-M201 and Q-M242 on the basis of 421 (of them 282 novel) high-coverage chrY sequences collected from large-scale databases focusing on populations of NEE. Within these otherwise rare haplogroups we disclose lineages that began to radiate ~1–3 thousand years ago in Estonia and Sweden and reveal male phylogenetic patterns testifying of comparatively recent local demographic expansions. Conversely, haplogroup Q lineages bear evidence of ancient Siberian influence lingering in the modern paternal gene pool of northern Europe…

For context, over 90% of the Y chromosomal lineages in Northeastern Europe localize to just four haplogroups. R1a, R1b, I1, and N3 (TAT-C). R1a and R1b are associated with early Indo-Europeans. I1 is local to European hunter-gatherers, but probably got integrated early on into the Corded Ware lineages (it shows recent star phylogeny). N3 is associated with the male-mediated expansion of Siberians over the last 3,000 years and the expansion of Finnic languages in the region.

Taking a step back it’s rather shocking how high the frequency here is of these common lineages. Finland stands out: “the screened sample of 506 Finnish males we did
not detect any rare NEE lineages as almost all Finnish samples belong to hgs common among neighbouring populations – a probable reflection of either differing migration history or of demographic bottleneck(s) that have affected the Finnish population.” This is partly due to the overwhelming dominance of N3 in Finland. But, it is also a function of the fact that Neolithic agriculture never took root in Finland. The “Neolithic” ancestry is Finland is due to Corded Ware migration, and that varied depending on the Corded War population (some of the early Corded Ware in Estonia seem to have been pure Yamnaya).

G-M201 seem to be survival from European farmers. The low frequency of this lineage shows the great winnowing of older paternal lineages with the arrival of Corded Ware. Not totally clear about J2 in this paper, but that too might be a survival. The E2 lineage they adduce to hunter-gatherers associated with the Villabruna culture, because the coalescence with Middle Eastern lineages is too ancient (E has been found in Villabruna). Seems weak. But the result on Q is fascinating. I assumed it came with the Corded Ware or the Siberian migration. But it’s not really found in the Finns, and the Estonian lineages seem to be derived from the more common Swedish ones? The authors infer from this that it’s a hunter-gatherer (Scandinavian hunter-gatherer) survival, as this lineage has been found in Mesolithic European populations. I still think it might be due to Corded Ware, as Q is found in some of the Sintashta too. But it warrants further investigation.

Men of the North

Posted on by Razib Khan
RegionI1I2*/I2aI2bR1aR1bGJ2J*/J1E1b1bTQN
Russia510.504661302.51.51.523
Lithuania66138500010.50.542
Latvia611401200.500.50.50.538
Estonia1530.53280102.53.50.534
Finland2800.553.50000.50061.5
Sweden371.53.51621.512.50302.57
Norway31.504.525.53210.501012.5
Denmark3425.515332.5302.5011

(Y chromosomal haplogroups)

A few weeks ago I saw the Y chromosomal haplogroup group distribution in Finland and Sweden. I’d know this disjunction for a while, but it really struck me. I got the numbers above from Eupedia, but you can find them elsewhere. Most of you probably know that Finland has a high fraction of N (they keep changing the nomenclature, so I’ll leave the number off). What’s curious to me is how low the fraction of N in the rest of Scandinavia is. Much of the N we see in Sweden may even be historical era migration of Finns into Sweden when the two nations were in political union (Finland was basically a Swedish colony).  Another notable fact is that N is very common among Baltic people, whether Finnic in the language (Estonian) or Indo-European (Latvian and Lithuanian).

Another strange thing is that while the Indo-European lineages of R1 are both at very low frequency in Finland, I1, which is common to the west in Scandinavia, is not. The latest ancient DNA makes it clear that Finnic languages seem to have arrived in the Baltic in the period between 1000 and 500 BC. Before then Corded Ware/Battle Axe people seem to have been dominant in the East Baltic. These people usually carried Y chromosome R1a.

The fact that N is so high in the Baltic nations shows that newcomers arrived, and in the northern region language shifted happened, but in the south, it did not. Meanwhile, further north in Finland almost all the R1a lineages disappeared. Not so with I1. There are all sorts of tortured explanations for this pattern, so I won’t offer one.

Genome-wide the Finns aren’t that different. The largest proportion of their ancestry is still Yamnaya/steppe:

I only post this to illustrate how strong “male-mediated” dynamics can be. The proportion of Siberian ancestry in Finns is rather low, but > 50% of their Y chromosomes are N. I think it is plausible that one of the reasons for the massive reduction in R1 in Finland might be due to climate change and massive population collapse among the Battle Axe people of southern Finland, and the later arrival of Siberians.

Australasian ancestry in Pacific coast Americans?

Posted on by Razib Khan

About five years ago researchers discovered that there was some affinity between people in the Amazon and populations in Australasia. This was very strange but robust. After that, an ancient sample from Brazil also showed this affinity.

Now PNAS has a paper with a bigger data set that finds this ancestry more widely in South America:

Different models have been proposed to elucidate the origins of the founding populations of America, along with the number of migratory waves and routes used by these first explorers. Settlements, both along the Pacific coast and on land, have been evidenced in genetic and archeological studies. However, the number of migratory waves and the origin of immigrants are still controversial topics. Here, we show the Australasian genetic signal is present in the Pacific coast region, indicating a more widespread signal distribution within South America and implicating an ancient contact between Pacific and Amazonian dwellers. We demonstrate that the Australasian population contribution was introduced in South America through the Pacific coastal route before the formation of the Amazonian branch, likely in the ancient coastal Pacific/Amazonian population. In addition, we detected a significant amount of interpopulation and intrapopulation variation in this genetic signal in South America. This study elucidates the genetic relationships of different ancestral components in the initial settlement of South America and proposes that the migratory route used by migrants who carried Australasian ancestry led to the absence of this signal in the populations of Central and North America.

The intrapopulation variation makes me suspicious. If it has been tens of thousands of years I would have expected intra-population variation to disappear.

The statistic looks correct. But we still don’t know what that means. The hypothesis presented about a coastal migration seems reasonable enough. But who knows?

The rise and fall of the Scythians

Posted on by Razib Khan

A new paper on Scythians in Science, Ancient genomic time transect from the Central Asian Steppe unravels the history of the Scythians:

The Scythians were a multitude of horse-warrior nomad cultures dwelling in the Eurasian steppe during the first millennium BCE. Because of the lack of first-hand written records, little is known about the origins and relations among the different cultures. To address these questions, we produced genome-wide data for 111 ancient individuals retrieved from 39 archaeological sites from the first millennia BCE and CE across the Central Asian Steppe. We uncovered major admixture events in the Late Bronze Age forming the genetic substratum for two main Iron Age gene-pools emerging around the Altai and the Urals respectively. Their demise was mirrored by new genetic turnovers, linked to the spread of the eastern nomad empires in the first centuries CE. Compared to the high genetic heterogeneity of the past, the homogenization of the present-day Kazakhs gene pool is notable, likely a result of 400 years of strict exogamous social rules.

This follows up on earlier work on Scythians and Sarmatians. The basic finding seems to be that the classical Scythians, an Iranian-speaking nomadic group, had an ethnogenesis in the eastern Kazakh steppe. And, their origins involve the amalgamation of earlier Bronze Age Eurasian pastoralists, probably out of the Indo-Iranian Andronovo horizon societies, with admixture with Bactria-Margiana populations to the south, and East Asian Bronze Age hunter-gatherers and pastoralists, to the east in Mongolia. The Sarmatians, also presumably Iranian-speaking, are somewhat different in that they had less East Asian ancestry, though they too had more Near Eastern ancestry than earlier Indo-Iranian steppe pastoralists.

The whole paper is worth reading. But I think the key thing to note is that Iron Age steppe pastoralists seem to have been much more interconnected with each other and with the world around them than their Bronze Age predecessors. Though there was some gene flow to the steppe from West Asia and elsewhere during the Bronze Age, it was a marginal phenomenon. By the Iron Age, it was ubiquitous. Additionally, there was now structure and connectedness across the steppe.

By the Iron Age the steppe had become an integrated social-political unit.

The French Bronze Age is what matters

Posted on by Razib Khan

A new preprint on ancient DNA, Ancient genomes from present-day France unveil 7,000 years of its demographic history. It goes from the late Pleistocene to the Iron Age, and has a lot of Neolithic samples, as well as Mesolithic and Bronze Age samples

Major takeaways:

– The Magdalenian populations, as represented by Goyet2, seem to have contributed ancestry to groups in substantial numbers down to the Mesolithic period. Earlier work showed the persistence of this group mostly in Iberia, but these data suggest they were present in France, and perhaps even Central Europe.

– The Neolithic populations are what you’d expect. The transition is what you’d expect (little initial admixture, later increase in Mesolithic hunter-gatherer ancestry). That being said, they seem to not establish whether the Neolithic farmers in France were mostly Cardial [Southewest European] or LBK [Central European]. It seems they lean to the proposition that they were more Cardial. Certainly for the southern samples.

– The arrival of the Beaker Culture heralded major genetic change as in Britain, though perhaps not as much. R1b became common, and steppe ancestry as well was ubiquitous. But, there was lots of variation. One of their samples is only about 25% steppe (the balance Neolithic-farmer), while another is 100% steppe. Southwest France, which had many non-Indo-European speakers until relatively late, had more Mesolithic hunter-gatherer and less steppe.

– Unlike in Iberia, there was significant mtDNA turnover. What this means is that the Indo-European expansion into Iberia was very male-mediated, but it France it wasn’t. Though the Neolithic impact seems higher than in Britain, on the whole there seem broad similarities here.

– The shift from the Bronze Age to the Iron Age didn’t result in a change in the average ancestry, but the variance seems to have decreased. The reason for this is that prehistoric France seems to have been undergoing genetic mixing across reagions.

– Finally, strong very recent selection on lactse persistence and pigmentation.

The deep origins of the Han Chinese

Posted on by Razib Khan

A new paper came out today on ancient East Asian DNA. More precisely, this work focused on early and late Neolithic samples from China, especially the lower Yellow river basin (north-central China) and the Fujian in southeast China. A major result can be boiled down to the Admixturegraph to the right.

The first ancient DNA out of East Eurasia was that from Tianyuan cave near modern Beijing. As you can see that individual is basal to other ancient (and modern) East Asians. That is, it isn’t representative of the ancestors of modern East Asians. But, the Tianyuan individual was already closer to modern East Asians than West Eurasians. Since the Tianyuan individual is ~40,000 years old, that means the bifurcation between eastern and western Eurasian groups predates 40,000 years ago.

This is not a surprising result, as the bifurcations between various “eastern” Eurasian groups (e.g., the ancestors of the Andamanese and East Asians) date to close to 50,000 years ago. The separation from Western Eurasians had to have happened after ~55,000 years ago since that’s about when the common shared Neanderthal admixture occurred.

The graph also shows that some ancient West Eurasian ancestry did come into the ancestors of East Asians through Siberians. More precisely, the Paleo-Siberian populations (replaced more recently by Neo-Siberian groups) had some ancestry from Ancient North Eurasians, who themselves were ~70% West Eurasian in ancestry (the other ~30% being a deeply basal East Eurasian). These Paleo-Siberians contributed ancestry to many northern East Asian groups, and likely explain the affinity between these groups and the Mal’ta-related individuals.

Finally, most of the edges show the separations between northern and southern East Asians and differences between inland and coastal populations. Though there is a deep distinction between northern and southern groups, the paper makes it clear that there is gene flow between coastal groups. This may explain affinities between the Japanese and Koreans, and peoples in southern China.

In terms of broad dynamics, one pattern that is evident, and repeats what we see all across Eurasia, is that the more recent periods seem to have undergone some level of panmixia. Ancient samples from northern and southern China are well differentiated, with pairwise Fst of around 0.04. Modern individuals sampled from these regions are closer to 0.02. Part of this is due to a significant expansion of “northern” ancestry at the expense of “southern”. But there is also some flow northward of “southern” ancestry. Though not highlighted in this paper because they lacked the samples, the movement throughout the Chinese Empire over the last 2,000 years is surely mediating this. In instances of famine or war resulting in depopulation in a province, the Chinese central authorities routinely encouraged migration from overpopulated provinces (modern Sichuan was repopulated from Hunan after a series of wars during the Ming-Qing transition). After 800 AD the demographic center China was in the Yangzi river valley, and south.

Unsurprisingly, the authors find that the southern samples from Fujian seem most similar to Austronesians. Today no one from these regions is “pure” southern. Rather, they are a mix. The Austronesians migrated out early enough that they carry southern East Asian ancestry exclusively. This recapitulates a common phenomenon where the ancestral “homeland” of a given group changes over time, reducing the ability to infer origins (e.g., the percentage of “Middle Eastern” ancestry in Southern Europe was underestimated because Anatolian farmers were partially replaced in Anatolia by migrants from the east).

There are also details in the supplements which confirm earlier inferences. For example, the Tianyuan individual has affinities with the Goyet Aurginacian sample from Belgium which dates to 35,000 years ago. But other East Asians do not. This seems to imply that Tianyuan was much more closely connected to a population that had trans-Eurasian affinities (another possibility is ancient structure, but the bifurcation between eastern and western Eurasian populations was more than 15,000 years before the time of Goyet so I am skeptical). Additionally, they also detect possible gene flow into Mesolithic Europeans from a population with East Asian ancestry (one possibility here that doesn’t seem to be explored is shared Ancient North Eurasian ancestry into both groups).

What is the overall takeaway? I think this confirms the other early papers that East Asia exhibits more continuity with its past that Europe and South Asian, rather like West Asia. While Europeans and South Asians have substantial ancestry from profoundly intrusive groups during the Holocene, the Han Chinese are in many ways “sons of the soil.” They did to some extent marginalize and absorb many other peoples in the modern area of “China proper”, and are themselves as a compound of two ancestral streams, but at the end of the last Ice Age, more than 90% of their ancestors were living within the boundaries of China proper.

More generally, modern imperial polities are exactly what some of their critics accuse of them of being: panmixia machines. Pre-state people were more genetically differentiated across local spatial scales. This seems the case everywhere there are good transects.

Related: The Deep Origins Of East Eurasians.

West Asian Ancestry in Knanaya greater than “Nasrani” which is greater than Mappila

Posted on by Razib Khan
click to enlarge
unsupervised

Since I last blogged about the Knanaya Christians of Kerala my collaborator has gotten me more samples from this southern state. I decided to look at all the Knanaya (I’m nearly 20 samples now), the 5 Nasrani I have, and 2 Nairs and 2 Mappila.

I’m running some more detailed analyses, but I thought I would pass on what I’ve found out so far. You can see in the PCA and in the unsupervised admixture plot to the right and the supervised plot to the left that Knanaya are enriched for West Asian ancestry. I included Yemeni Jews since they are one end of the “pole.” The Middle Eastern ancestry of the Knanaya are likely to be Semitic, not Iran. These results confirm it.

supervised

The Nasrani samples I have also show this pattern. But it is attenuated. Finally, the two Mappila, Muslims from Kerala, do not show a shift at all. The two Nair are in the same place as South Indian Brahmins. This is likely the consequence of sambandam.

All that being said, I feel that the Kerala populations as a whole are often “west-shifted.” Why? My hunch is that the seaborn trade with the “west” was long-standing and pretty extensive.

Finally, I’m always struck by how some North Indian groups have more “steppe” ancestry than Iranians.

The Empire of the Silk Road and the “Babel of Nations”

Posted on by Razib Khan

Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present is one of my favorite books because it combines erudition with trenchent and opinionated analysis. One of the arguments explicit within the author’s narrative is that the geographic parameters of Eurasian steppe created a set of societies and cultures which shaped world-history. In particular, implicit within Empires of the Silk Road is the thesis explicit in The Shape of Ancient Thought: Comparative Studies in Greek and Indian Philosophies, that Eurasian steppe pastoralists served as innovators and mediators of cultural motifs and practices across the Eurasian oikoumene. In Halford Mackinder’s formulation the “Rimland” and “Heartland” were symbiotic.

A new preprint, A dynamic 6,000-year genetic history of Eurasia’s Eastern Steppe, illuminates the genetic/demographic dynamics in an important region of the steppe:

The Eastern Eurasian Steppe was home to historic empires of nomadic pastoralists, including the Xiongnu and the Mongols. However, little is known about the region’s population history. Here we reveal its dynamic genetic history by analyzing new genome-wide data for 214 ancient individuals spanning 6,000 years. We identify a pastoralist expansion into Mongolia ca. 3000 BCE, and by the Late Bronze Age, Mongolian populations were biogeographically structured into three distinct groups, all practicing dairy pastoralism regardless of ancestry. The Xiongnu emerged from the mixing of these populations and those from surrounding regions. By comparison, the Mongols exhibit much higher Eastern Eurasian ancestry, resembling present-day Mongolic-speaking populations. Our results illuminate the complex interplay between genetic, sociopolitical, and cultural changes on the Eastern Steppe.

The Eastern Eurasian Steppe was home to historic empires of nomadic pastoralists, including the Xiongnu and the Mongols. However, little is known about the region’s population history. Here we reveal its dynamic genetic history by analyzing new genome-wide data for 214 ancient individuals spanning 6,000 years. We identify a pastoralist expansion into Mongolia ca. 3000 BCE, and by the Late Bronze Age, Mongolian populations were biogeographically structured into three distinct groups, all practicing dairy pastoralism regardless of ancestry. The Xiongnu emerged from the mixing of these populations and those from surrounding regions. By comparison, the Mongols exhibit much higher Eastern Eurasian ancestry, resembling present-day Mongolic-speaking populations. Our results illuminate the complex interplay between genetic, sociopolitical, and cultural changes on the Eastern Steppe.

The Xiongnu are important for two reasons. The less interesting reason is that they are posited to be the forerunners of the Huns. The more interesting reason is that many historians suggest that the emergence of organized steppe pastoralist polities on the northern and western flank of China drove the integration of the Han into a singular imperial system.

Though the historical dynamics are outside of the purview of this post, these results confirm that the advanced stages of the Xiongnu confederation were attractive to a diverse array of peoples, from steppe Iranians to Han.

click to enlarge

The time transect is probably best illustrated by this figure from the supplements:

The enormous demographic impact of the Indo-Europeans

Posted on by Razib Khan


When I was a kid I remember seeing a map of the distribution of Indo-European languages, and being perplexed by their spread and distribution, from the North Sea to the Bay of Bengal. Later, I learned and understood that language families can spread by diffusion and cultural assimilation. In The Horse, the Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World David Anthony outlines an elite emulation model of the Indo-Europeanization, whereby groups of warriors associated with the Kurgan cultures took over and reshaped a broad range of societies.

The samples Anthony provided were instrumental in recalibrating his own model. It turns out that steppe migrants were extremely genetically impactful. Rather than a small minority, many archaeological cultures seem to have been predominantly steppe in genetic origin (total number of ancestors). The best estimates seem to be that ancestry from the steppe is somewhat more than half the total in northern and eastern Europe, and somewhat less than half in southern and western Europe (i.e., northeast to southwest cline).

More recently, it also seems that a substantial, though a smaller, proportion of the ancestry in southern Asia also derives from the steppe peoples. Within India itself, the range seems to be from 25-30% among some groups, such as North Indian Brahmins and Jatts, to a more typical range between 5 and 15% (peasant castes in South India are closer to the former, peasant castes in the Gangetic plain are closer to the latter).

Using the proportions in various ethnic groups in the Indian subcontinent, as well as across European nations, I have come to conclude that around ~10% of the ancestry in the world derives from people who were members of the “Yamna Horizon” ~3000 BC.* I don’t know the archaeology well enough to be highly informed, but I’m willing to bet that closer to 1% of the world’s population lived in and around the Yamna Horizon, so over the last 5,000 years, you’ve seen a 10-fold increase in representation of this ancestral component. More concretely, I think that the vast majority of the increase occurred between 2500 BC (when expansions into Britain and Southern Europe seem to have occurred) and 1000 BC (when the core area of the Indian subcontinent was Aryanized).

* I did stuff like weighted caste groups in Uttar Pradesh, looked at the populations of India states, added Pakistan and Bangladesh, as well as assigning estimates to European countries. I did some back-of-the-envelope for North and South America (e.g., assume that 50% of the ancestry is Iberian, and assume that 25% of that 50% is steppe).

Afrikaner genetics shows how unique New England culture is

Posted on by Razib Khan

There’s a new paper in BMC Biology, Patterns of African and Asian admixture in the Afrikaner population of South Africa, which confirms some of what I found years ago with a much smaller data set, The Genetics Of Afrikaners (Again). The PCA above and Treemix to the right I generated from the data in the new paper.

Here are their results:

To investigate the genetic ancestry of the Afrikaner population today (11–13 generations after initial colonization), we genotyped approximately five million genome-wide markers in 77 Afrikaner individuals and compared their genotypes to populations across the world to determine parental source populations and admixture proportions. We found that the majority of Afrikaner ancestry (average 95.3%) came from European populations (specifically northwestern European populations), but that almost all Afrikaners had admixture from non-Europeans. The non-European admixture originated mostly from people who were brought to South Africa as slaves and, to a lesser extent, from local Khoe-San groups. Furthermore, despite a potentially small founding population, there is no sign of a recent bottleneck in the Afrikaner compared to other European populations. Admixture amongst diverse groups from Europe and elsewhere during early colonial times might have counterbalanced the effects of a small founding population.

Afrikaner ancestry is overwhelmingly Northern European. But as you see in the PCA above they are notably African and Asian shifted when compared to their potential ancestral populations (I used Dutch and German individuals above). For me this is the part that is important, if not surprising:

The individual with the most non-European admixture had 24.9% non-European admixture, and only a single Afrikaner individual (out of 77) had no evidence of non-European admixture…Amongst the 77 Afrikaners investigated, 6.5% had above 10% non-European admixture, 27.3% between 5 and 10%, 59.7% between 1 and 5% and 6.5% below 1%.

So about 87% of Afrikaners in their sample had between 1 to 10 percent non-European ancestry. As suggested by genealogical evidence, genetics indicates this is a relatively recent admixture, occurring during the 17th and 18th-century. The early decades of the Cape Colony. It’s a mix of diverse Asian and African components. In some ways, it seems that the non-European ancestry in modern Afrikaners is just the same phenomenon which gave rise to the Cape Coloured population, which is a mix of European, Asian (Indian and Austronesian) and African (Bantu and Khoisan).

Honestly, I think the individuals with more than 10% non-European ancestry, or 0% non-European ancestry, may have recent non-Afrikaner ancestry, and so are not representative (Hendrik Verweord was Dutch and immigrated to South Africa, so he would not have had non-European ancestry). Arguably, the fact that Afrikaners are only ~5% non-European is rather surprising in light of the conditions of the Cape Colony during its early years.

But, this result is more interesting in light of how it contrasts with another case. Also in the 17th-century, there emerged another European settler society on the edge of a vast ocean rooted in a deeply Calvinist faith. By this, I mean the colonies of New England. Though New England has been reshaped by later migrations, between 1640 and 1790 30,000 English settlers expanded and grew into a region with 750,000 Americans. In the early 19th-century, New England spilled out over much of the northern swath of the United States of America, in part due to the fact that the fertility of New Englanders was quite high (the early Mormons were fundamentally a New England-derived subculture).

And yet unlike the Afrikaners or the whites of Latin America, the scions of New England have no non-European ancestry. One might argue here that this is due to the lack of opportunity, as the number of slaves in New England was always very low, and there were no native peoples. King Philip’s War falsifies the latter contention. There were numerous native people. At least initially. But the New Englanders were very efficient and effective at marginalizing and exterminating the native peoples of the region. To a far greater extent than occurred in the South.

There was no New England “Trail of Tears,” because New Englanders eliminated most of the local tribes. There are even records New England militias in the 17th-century drowning native children in the Connecticut River as an ultimate solution (to the chagrin and concern of some ministers who wished these children to be baptized and raised as Christians).

Of course, another distinctive aspect of the New England settlement is that it was the transplantation of a whole English society, men and women, rather than simply men seeking fortune and opportunity. This sex balance from the beginning meant that there was no necessity of looking for partners in the local population, as often occurred in other colonial contexts.

The lack of any local imprint on New England’s genetics, in contrast with almost all other settler and colonial societies, is in keeping with the other peculiarities of the region’s cultures. By the latter portion of the 18th-century New England was unique because it was beginning to see itself as not just a complement of the metropole, but a potential rival.* A potential that would be realized with the intellectual (the emergence of Harvard) and economic (industrialization) developments of the 19th-century.

Today when talking to Patrick Wyman of Tides of History, I suggested that genetics can only be understood in a broader context, even if it is to answer specific questions. Though European settler societies are all predominantly European, both culturally and biologically, New England’s uniqueness genetically in having almost no native input reflects I think a broader cultural reality of the region’s history: it is peculiarly European without much synthesis with the local substrate.

* The South was a traditional commodity-exporting colony. The Mid-Atlantic, focused on New York City, was the center of mercantile activity that operated as a transaction hub of a global trade system.