European Ancestry of Ashkenazi Jews

March 8, 2014

According to a new genetic study, Ashkenazi Jews are mostly European on their maternal side, and that admixture comes from Western and Central Europe when diaspora males from the Levant arrived first in Rome and found wives among local Italian women who converted to Judaism. They then migrated further west and north and acquired other European admixture in the same way, before finally heading east. Intermixing slowed after that because they have very little Slavic or Turkic (Khazar) admixture. Their paternal side remains mostly Near Eastern. This all fits well with findings from anthropology some 75 years ago.

Overall, it seems that at least 80% of Ashkenazi maternal ancestry is due to the assimilation of mtDNAs indigenous to Europe, most likely through conversion. The phylogenetic nesting patterns suggest that the most frequent of the Ashkenazi mtDNA lineages were assimilated in Western Europe, ~2 ka or slightly earlier. Some in particular, including N1b2, M1a1b, K1a9 and perhaps even the major K1a1b1, point to a north Mediterranean source. It seems likely that the major founders were the result of the earliest and presumably most profound wave of founder effects, from the Mediterranean northwards into central Europe, and that most of the minor founders were assimilated in west/central Europe within the last 1,500 years. The sharing of rarer lineages with Eastern European populations may indicate further assimilation in some cases, but can often be explained by exchange via intermarriage in the reverse direction.

The Ashkenazim therefore resemble Jewish communities in Eastern Africa and India, and possibly also others across the Near East, Caucasus and Central Asia, which also carry a substantial fraction of maternal lineages from their 'host' communities. Despite widely differing interpretations of autosomal data, these results in fact fit well with genome-wide studies, which imply a significant European component, with particularly close relationships to Italians. As might be expected from the autosomal picture, Y-chromosome studies generally show the opposite trend to mtDNA (with a predominantly Near Eastern source) with the exception of the large fraction of European ancestry seen in Ashkenazi Levites.

Evidence for haplotype sharing with non-Ashkenazi Jews for each of the three main haplogroup K founders may imply a partial common ancestry in Mediterranean Europe for Ashkenazi and Spanish-exile Sephardic Jews, but may also, at least in part, be due to subsequent gene flow, especially into Bulgaria and Turkey, both of which witnessed substantial immigration from Ashkenazi communities in the fourteenth and fifteenth centuries. Gene flow could have been substantial in some cases—ongoing intermarriage is likely when these communities began living in closer proximity after the Spanish exile. A partial common ancestry for all European Jews—both Ashkenazi and Sephardic—is again strongly supported by the autosomal results.

Jewish communities were already spread across the Graeco-Roman and Persian world >2,000 years ago. It is thought that a substantial Jewish community was present in Rome from at least the mid-second century BCE, maintaining links to Jerusalem and numbering 30,000-50,000 by the first half of the first century CE. By the end of the first millennium CE, Ashkenazi communities were historically visible along the Rhine valley in Germany. After the wave of expulsions in Western Europe during the fifteenth century, they began to disperse once more, into Eastern Europe.

These analyses suggest that the first major wave of assimilation probably took place in Mediterranean Europe, most likely in the Italian peninsula ~2 ka, with substantial further assimilation of minor founders in west/central Europe. There is less evidence for assimilation in Eastern Europe, and almost none for a source in the North Caucasus/Chuvashia, as would be predicted by the Khazar hypothesis—rather, the results show strong genetic continuities between west and east European Ashkenazi communities, albeit with gradual clines of frequency of founders between east and west.

Costa et al. "A substantial prehistoric European ancestry amongst Ashkenazi maternal lineages". Nature Communications, 2013.

The Jews have been left to the end because they do not as a whole fit into any single racial classification heretofore outlined. Historically the Jews of the Biblical period in Palestine were a Semitic-speaking people composed of various Mediterranean strains which had blended together at the time of the formation of the Jewish nation. These Mediterranean strains must have included a small Mediterranean type comparable to the present Yemeni Arabs; a taller, longer-faced strain with a tendency to nasal convexity, as is found among Irano-Afghan peoples today; and a straight-nosed, presumably Atlanto-Mediterranean element contributed by the Philistines.

The Jews began their expansion from Palestine as early as the time of the Babylonian Captivity; at this time they settled Mesopotamia in large numbers, and from there began an expansion into central Asia of which colonies still remain. In the Hellenistic period they migrated into Asia Minor and the Black Sea region, as well as into Egypt; these emigrants became Hellenistic Jews. Under the Romans they settled in Italy, France, and Spain, with especial concentrations in Spain and in the cities of the Rhineland. The Jews expelled from Spain in 1492 and during previous expulsions became the Sephardim, whose descendants are to be found in various countries bordering on the Mediterranean, especially Morocco, the Salonika region of what is now Greece, and Turkey. The Rhineland Jews, persecuted at the time of the First Crusade, moved eastward into Poland, the Ukraine and other central European countries, and met there and absorbed a group of Hellenistic Jews moving westward, among whom were some who had lived among the Turkish Khazars in the Crimea and elsewhere. The two groups blended and the Germanic speech of the more numerous western element prevailed. The modern Yiddish-speaking Ashkenazim are the descendants of this amalgamated body. Racially they preserve to a large measure their Mediterranean character, altered partly by Alpine admixture which has in many cases produced Dinaricization. This Alpine, as well as some Nordic, admixture was probably obtained largely in France and Germany before their departure eastward. The most persistent Palestinian Mediterranean traits which the Jews preserve is a narrowness of the face. The Jewish facial expression, by which many Jews may be distinguished, is a cultural and not a genetic character.

Carleton Coon. The Races of Europe. New York: MacMillan, 1939.

Semitic West Eurasian Ancestry in Africa

February 6, 2014

This new study confirms everything that Afrocentrists deny about Caucasoid admixture in East (and South) Africa.

Back-to-Africa Gene Flow in Eastern Africa


A major open question concerns the initial source of the west Eurasian ancestry in eastern Africa. The estimated mean time of gene flow in eastern Africa is around 3,000 y ago, and the amount of gene flow must have been quite extensive, because the west Eurasian ancestry proportions reach 40-50% in some Ethiopian populations (Table 1 and ref. 10). Archaeological records from this region are sparse, so Pagani et al. (10) speculate that this admixture is related to the Biblical account of the Kingdom of Sheba. However, archaeological evidence is not completely absent. During this time period, architecture in the Ethiopian culture of D'mt has an "unmistakable South Arabian appearance in many details" (19), although there is some debate as to whether these patterns can be attributed to large movements of people versus elite-driven cultural practices (19, 20). Additionally, linguistic evidence suggests that this time period was when Ethiosemitic languages were introduced to Africa, presumably from southern Arabia (21). It is perhaps not a coincidence that the highest levels of west Eurasian ancestry in eastern Africa are found in the Amhara and Tygray, who speak Ethiosemitic languages and live in what was previously the territory of D'mt and the later kingdom of Aksum.

West Eurasian Ancestry in Southern Africa


A second question is, which population or populations introduced west Eurasian ancestry into southern Africa? The best genetic proxy for this ancestry that we have found is the west Eurasian ancestry in eastern Africa (Fig. 1C), and although we do not identify modern east African populations as the best source population, this is likely due to the lack of genetic drift specific to eastern Africa (SI Appendix, section 1.2.3). The most parsimonious explanation for this observation is that west Eurasian ancestry entered southern Africa indirectly via eastern Africa (the alternative scenario of direct contact with an unsampled west Eurasian population cannot formally be excluded; however, there is no archaeological, historical, or linguistic evidence of such contact). The relevant eastern African population may no longer exist. However, such a migration has been suggested based on shared Y chromosome haplotypes (12, 22) and shared alleles/haplotypes associated with lactase persistence (2, 23) between the two regions. Furthermore, based on a synthesis of archaeological, genetic, climatological, and linguistic data G├╝ldemann (13) hypothesized that the ancestor of the Khoe-Kwadi languages in southern Africa was brought to the region by immigrating pastoralists from eastern Africa. Our observation of elevated west Eurasian ancestry in Khoe-Kwadi groups in general (Table 1) is consistent with this hypothesis.

[...]

Conclusions


Based on these analyses, we can propose a model for the spread of west Eurasian ancestry in southern and eastern Africa as follows. First, a large-scale movement of people from west Eurasia into Ethiopia around 3,000 y ago (perhaps from southern Arabia and associated with the D'mt kingdom and the arrival of Ethiosemitic languages) resulted in the dispersal of west Eurasian ancestry throughout eastern Africa. This was then followed by a migration of an admixed population (perhaps pastoralists related to speakers of Khoe-Kwadi languages) from eastern Africa to southern Africa, with admixture occurring ~1,500 y ago. Advances in genotyping DNA from archaeological samples may allow aspects of this model to be directly tested.


Pickrell et al. "Ancient west Eurasian ancestry in southern and eastern Africa". PNAS, 2014.

Global Admixture Analysis at K=6

December 31, 2013

This new study has one of the biggest global admixture analyses ever done (185 populations at 293,832 SNPs), but it's a little hard to view so I made a more user friendly version of one of the runs. I chose K=6 because it shows clearly the divisions and admixture between the six main racial groups: Capoid (red), Negroid (orange), Caucasoid (blue), Americoid (green), Mongoloid (yellow) and Australoid (purple). Click the image below to enlarge it and scroll down for examples of the racial types.


K=2 separates African from non-African populations.

K=3 reveals a West Eurasian ancestry component [Blue].

K=4 breaks the African component into an African hunter-gatherer ancestry maximized in Bushmen such as the Ju_hoan_North [Red] and an African farmer component maximized in the Yoruba [Orange].

K=5 breaks the ENA [eastern non-African] component down into one maximized in the Karitiana from the Americas [Green] and one maximized in the Ami from Taiwan [Yellow].

K=6 reveals a south Eurasian component maximized in Papuans [Purple], which is also represented in South Asians.


Ju'hoan (Namibia)
"Capoid"
Yoruba (Nigeria)
"Negroid"
Sardinian (Italy)
"Caucasoid"


Karitiana (Brazil)
"Americoid"
Ami (Taiwan)
"Mongoloid"
Papuan (PNG)
"Australoid"

Calling Out JayMan

November 28, 2013

JayMan is an HBd blogger obsessed with IQ, heredity and achievement, and probably Richard Lynn's #1 fan. He claims to be Jamaican, which makes him either the most insanely self-hating black person on earth, or a white Nordicist pretending to be black so he can get away with insulting blacks and everyone else who isn't Northwestern European. Either way, he's an idiot.

Recently he "called me out" on his blog re: my stance on environmental factors in global IQ disparities. I had debated him there about a year and a half ago and easily won, and I guess he's been traumatized by it ever since. He links to that post in his new one, and I wondered why he would want to remind people of his defeat, but when I checked it again I noticed that he'd deleted my final reply to try and make himself look like the winner (you can read the unedited discussion here; the deleted comment is "Mar 27 2012 9:57 AM"). Then when I attempted to reply to his latest "challenge" the other day, he refused to approve that comment too. Just thought you'd want to know what a pathetic, dishonest, chickenshit loser he is...if you couldn't already tell.

Anyway, my response to his nonsense was this study showing that poverty leads to a significant drop in IQ points, and this new one which concludes similarly that the wealth of nations determines "national IQs" (not the other way around).

Haplogroups L3 and E are Asian, not African

October 28, 2013

The latest evidence suggests that two major haplogroups long considered African actually arose in Asia and then back-migrated to Africa.

The presence of the L haplogroup common in Africa was unexpected given the clustering of the Saudis with Europeans in the phylogenetic tree and suggests some recent African admixture. To examine this further, we performed formal tests for a history of admixture and found no evidence of African admixture in the Saudi after the split. Taken together, these analyses suggest that the L3 haplogroup found in the Saudi were present before the bottleneck 50,000 YBP. Given the TMRCA estimates for the L3 haplogroup of approximately 70,000 YBP and the timing of the Out-of-Africa split, these analyses suggest that L3 haplogroup arose in the Middle East with a subsequent back migration and expansion into Africa over the Horn-of-Africa during the lower sea levels found during the glacial period bottleneck.

Farrell et al. "The Saudi Arabian Genome Reveals a Two Step Out-of-Africa Migration". Am Soc Hum Genet, 2013.

It remained mysterious that how many times the anatomically modern human migrated out of Africa, since that among the three superhaplogrous C, DE and F, Haplogroup F distributes in whole Eurasia, C in Asia and Austronesia, D exclusively in Asia, while D's brother clade E distribute mainly in Africa, so there are two hypotheses, 1) haplogroups D and CF migrated out of Africa separately; 2) the single common ancestor of CF and DE migrated out of Africa followed by a back-migration of E to Africa. From this study, the short interval between CF/DE and C/F divergences weakens the possibility of multiple independent migrations (CF, D, and DE*) out of Africa, and thus supports the latter hypothesis (Fig. S2 a).

Shi Yan et al. "Y Chromosomes of 40% Chinese Are Descendants of Three Neolithic Super-grandfathers". arXiv:1310.3897 [q-bio.PE], 2013.

Poverty Lowers IQ

September 4, 2013

Poverty and all its related concerns require so much mental energy that the poor have less remaining brainpower to devote to other areas of life, according to research based at Princeton University. As a result, people of limited means are more likely to make mistakes and bad decisions that may be amplified by — and perpetuate — their financial woes.

Published in the journal Science, the study presents a unique perspective regarding the causes of persistent poverty. The researchers suggest that being poor may keep a person from concentrating on the very avenues that would lead them out of poverty. A person's cognitive function is diminished by the constant and all-consuming effort of coping with the immediate effects of having little money, such as scrounging to pay bills and cut costs. Thusly, a person is left with fewer "mental resources" to focus on complicated, indirectly related matters such as education, job training and even managing their time.

In a series of experiments, the researchers found that pressing financial concerns had an immediate impact on the ability of low-income individuals to perform on common cognitive and logic tests. On average, a person preoccupied with money problems exhibited a drop in cognitive function similar to a 13-point dip in IQ, or the loss of an entire night's sleep. But when their concerns were benign, low-income individuals performed competently, at a similar level to people who were well off, said corresponding author Jiaying Zhao, who conducted the study as a doctoral student in the lab of co-author Eldar Shafir, Princeton's William Stewart Tod Professor of Psychology and Public Affairs.

[...]

The cognitive effect of poverty the researchers found relates to the more general influence of "scarcity" on cognition, which is the larger focus of Shafir's research group. Scarcity in this case relates to any deficit — be it in money, time, social ties or even calories — that people experience in trying to meet their needs. Scarcity consumes "mental bandwidth" that would otherwise go to other concerns in life, Zhao said.

"These findings fit in with our story of how scarcity captures attention. It consumes your mental bandwidth," Zhao said. "Just asking a poor person to think about hypothetical financial problems reduces mental bandwidth. This is an acute, immediate impact, and has implications for scarcity of resources of any kind."

Morgan Kelly. "Poor concentration: Poverty reduces brainpower needed for navigating other areas of life". News at Princeton, August 29, 2013.

The poor often behave in less capable ways, which can further perpetuate poverty. We hypothesize that poverty directly impedes cognitive function and present two studies that test this hypothesis. First, we experimentally induced thoughts about finances and found that this reduces cognitive performance among poor but not in well-off participants. Second, we examined the cognitive function of farmers over the planting cycle. We found that the same farmer shows diminished cognitive performance before harvest, when poor, as compared with after harvest, when rich. This cannot be explained by differences in time available, nutrition, or work effort. Nor can it be explained with stress: Although farmers do show more stress before harvest, that does not account for diminished cognitive performance. Instead, it appears that poverty itself reduces cognitive capacity. We suggest that this is because poverty-related concerns consume mental resources, leaving less for other tasks. These data provide a previously unexamined perspective and help explain a spectrum of behaviors among the poor. We discuss some implications for poverty policy.

Mani et al. "Poverty Impedes Cognitive Function". Science, 2013.

Related: Parasite prevalence and cognitive development

Ancestry of Latinos

June 12, 2013

As they say, Hispanic is not a race. Latin Americans are a three-way mix of Europeans (from Spain), Native American Indians, and Sub-Saharan Africans, but proportions of these genetic components vary a lot both between and within different groups.

We find that the most likely source of the indigenous ancestry in Caribbean islanders is a Native South American component shared among coastal tribes from Venezuela, Central America, and the Yucatan peninsula, suggesting extensive gene flow across the Caribbean in pre-Columbian times. We find evidence of two pulses of African migration. The first pulse — which today is reflected by shorter, older ancestry tracts — consists of a genetic component more similar to coastal West African regions involved in early stages of the trans-Atlantic slave trade. The second pulse — reflected by longer, younger tracts — is more similar to present-day West-Central African populations, supporting historical records of later transatlantic deportation. Surprisingly, we also identify a Latino-specific European component that has significantly diverged from its parental Iberian source populations, presumably as a result of small European founder population size.

[...]

Figure 1B shows the distribution in PCA space of each individual, recapitulating clustering patterns previously observed in Hispanic/Latino populations: Mexicans cluster largely between European and Native American components, Colombians and Puerto Ricans show three-way admixture, and Dominicans principally cluster between the African and European components. Ours is the first study to characterize genomic patterns of variation from (1) Hondurans, which we show have a higher proportion of African ancestry than Mexicans, (2) Cubans, which show extreme variation in ancestry proportions ranging from 2% to 78% West African ancestry, and (3) Haitians, which showed the largest average proportion of West African ancestry (84%).


Assuming a K=3 admixture model, population admixture patterns are driven by continental reference samples with no continental subdivision (Figure 1C, top panel). However, higher Ks show substantial substructure in all three continental components. [...] At K=8, when the clinal gradient of differentiation between Southern and Northern Europeans appears, the Latino European component is seen only in low proportions in individuals from Portugal and Spain, whereas it is the major European component among Latinos (Figure 1C, bottom panel).


ADMIXTURE clustering analysis using the high-density dataset containing approximately 390K autosomal SNP loci in common across admixed and reference panel populations. Unsupervised models assuming K=3 and K=8 ancestral clusters are shown. At K=3, Caribbean admixed populations show extensive variation in continental ancestry proportions among and within groups. At K=8, sub-continental components show differential proportions in recently admixed individuals. A Latino-specific European component accounts for the majority of the European ancestry among Caribbean Latinos and is exclusively shared with Iberian populations within Europe. Notably, this component is different from the two main gradients of ancestry differentiating southern from northern Europeans. Native Venezuelan components are present in higher proportions in admixed Colombians, Hondurans, and native Mayans.


Moreno-Estrada et al. "Reconstructing the Population Genetic History of the Caribbean". arXiv:1306.0558 [q-bio.PE], 2013.

Racial Composition and History of India

December 10, 2012

DNA evidence confirms what historians, linguists and anthropologists have long known but nationalists have denied: that Indians are mainly a mix of indigenous Australoids and intrusive Caucasoids. They're composed of two genetic components, one related to Andaman Islanders and the other to Western Eurasians, which is higher in upper castes. The estimated dates of admixture between the two are consistent with the introduction of Indo-Aryan languages from the northwest and probably also earlier events related to the spread of Dravidian languages and even agriculture.

India has been underrepresented in genome-wide surveys of human variation. We analyse 25 diverse groups in India to provide strong evidence for two ancient populations, genetically divergent, that are ancestral to most Indians today. One, the "Ancestral North Indians" (ANI), is genetically close to Middle Easterners, Central Asians, and Europeans, whereas the other, the "Ancestral South Indians" (ASI), is as distinct from ANI and East Asians as they are from each other. By introducing methods that can estimate ancestry without accurate ancestral populations, we show that ANI ancestry ranges from 39-71% in most Indian groups, and is higher in traditionally upper caste and Indo-European speakers. Groups with only ASI ancestry may no longer exist in mainland India. However, the Andamanese are an ASI-related group without ANI ancestry, showing that the peopling of the islands must have occurred before ANI-ASI gene flow on the mainland. Allele frequency differences between groups in India are larger than in Europe, reflecting strong founder effects whose signatures have been maintained for thousands of years owing to endogamy. We therefore predict that there will be an excess of recessive diseases in India, which should be possible to screen and map genetically.



Reich et al. "Reconstructing Indian Population History". Nature, 2009.


Metspalu et al. "Shared and Unique Components of Human Population Structure and Genome-Wide Signals of Positive Selection in South Asia". Am J Hum Genet, 2011.

Linguistic and genetic studies have shown that most Indian groups have ancestry from two genetically divergent populations, Ancestral North Indians (ANI) and Ancestral South Indians (ASI). However, the date of mixture still remains unknown. We analyze genome-wide data from about 60 South Asian groups using a newly developed method that utilizes information related to admixture linkage disequilibrium to estimate mixture dates. Our analyses suggest that major ANI-ASI mixture occurred in the ancestors of both northern and southern Indians 1,200-3,500 years ago, overlapping the time when Indo-European languages first began to be spoken in the subcontinent. These results suggest that this formative period of Indian history was accompanied by mixtures between two highly diverged populations, although our results do not rule out other, older ANI-ASI admixture events. A cultural shift subsequently led to widespread endogamy, which decreased the rate of additional population mixtures.

Moorjani et al. "Estimating a date of mixture of ancestral South Asian populations", Evolutionary and Population Genetics, 2012.

The paper provides an overview of the spatial and temporal aspects of human morphological variation in India. Four morphological types — Australoids, Negritos, Mongoloids and Caucasoids — have been discerned in the contemporary Indian population. The Australoids appear to be the oldest and have evolved in India. The Caucasoids are physically heterogeneous and suggests incorporation of more than one physical type involving more than one migration. The within-type variance compared to between-type variance for characters studied is smaller. The paper further discusses the observed variability in terms of Indian social organization as well as in terms of endogamy, small numerical strength of the groups and varying ecological conditions prevalent in India.

K.C. Malhotra. "Morphological Composition of the People of India". J Hum Evol, 1978.


Indian Male Composite
Indian Female Composite


Assumed parental groups:


Andamanese Australoid
Iranian Caucasoid


Degrees of admixture:


Austroasiatic speaker
(Juang)
Austroasiatic speaker
(Santhal)


Dravidian speaker
(Paniya)
Dravidian speaker
(Hallaki)


Indo-European speaker
(Meghawal)
Indo-European speaker
(Kashmiri Pandit)

Welsh Are the Most Ancient Britons

July 5, 2012

The Welsh (and Cornish) may be the Sardinians of the UK: relatively pure descendants of prehistoric Britons, minimally altered by post-Neolithic gene flow. Interestingly, they and Sardinians are each the darkest and most racially Mediterranean populations in their respective countries, having the highest rates of black hair and brown eyes and the lowest rates of blondism (Coon, 1939: Ch. X, Sec. 3 and Ch. XI, Sec. 16).


Welsh people could lay claim to be the most ancient Britons, according to scientists who have drawn up a genetic map of the British Isles.

Research suggests the Welsh are genetically distinct from the rest of mainland Britain.

Professor Peter Donnelly, of Oxford University, said the Welsh carry DNA which could be traced back to the last Ice Age, 10,000 years ago.


The project surveyed 2,000 people in rural areas across Britain.

Participants, as well as their parents and grandparents, had to be born in those areas to be included in the study.

Prof Donnelly, a professor of statistical science at Oxford University and director of the Wellcome Trust centre for human genetics, said DNA samples were analysed at about 500,000 different points.

After comparing statistics, a map was compiled which showed Wales and Cornwall stood out.

Prof Donnelly said: "People from Wales are genetically relatively distinct, they look different genetically from much of the rest of mainland Britain, and actually people in north Wales look relatively distinct from people in south Wales."

While there were traces of migrant groups across the UK, there were fewer in Wales and Cornwall.

He said people from south and north Wales genetically have "fairly large similarities with the ancestry of people from Ireland on the one hand and France on the other, which we think is most likely to be a combination of remnants of very ancient populations who moved across into Britain after the last Ice Age.

"And potentially also, people travelling up the Atlantic coast of France and Spain and settling in Wales many thousands of years ago".

Mountains


He said it was possible that people came over from Ireland to north Wales because it was the closest point, and the same for people coming to south Wales from the continent, as it was nearer.

However he added: "We don't really have the historical evidence about what those genetic inputs were."

The geography of Wales made it more likely that ancient DNA would be retained.

Because of its westerly position and mountainous nature, Anglo-Saxons who moved into central and eastern England after the Romans left did not come that far west, and neither did the Vikings who arrived in around 900AD.


The professor said modern people from central and southern England had many genetic similarities to modern people in Denmark and Germany.

The mountains were also the reason why DNA may have remained relatively unchanged, as people would have found it harder to get from north to south Wales or into England compared with people trying to move across the flatter southern English counties, making them more likely to marry locally and conserve more ancient DNA.

"In north Wales, there has been relative isolation because people moved less because of geographical barriers," Prof Donnelly said.

He added that some of these factors also held true for the extreme edges of Scotland, while the Orkney islands showed DNA connections to Norway.

The next stage of the research will looking at physical similarities between different groups, in which the team will use photographs of people and make 3D models to measure quantitative similarities between related groups.

"Welsh people could be most ancient in UK, DNA suggests". BBC News, June 19, 2012.