January 18, 2015

Kennewick Man was Native American

First DNA tests say Kennewick Man was Native American
Genetic analysis is still under way in Denmark, but documents obtained through the federal Freedom of Information Act say preliminary results point to a Native-American heritage.

The researchers performing the DNA analysis “feel that Kennewick has normal, standard Native-American genetics,” according to a 2013 email to the U.S. Army Corps of Engineers, which is responsible for the care and management of the bones. “At present there is no indication he has a different origin than North American Native American.”

...

Willerslev’s Danish lab is a world leader in ancient DNA analysis. Last year, he and his colleagues reported the genome of the so-called Anzick boy, an infant buried 12,600 years ago in Montana. He, too, was a direct ancestor of modern Native Americans and a descendant of people from Beringia.

Until details of the Kennewick analysis are published, there’s no way to know what other relationships his genes will reveal, Kemp said. It may never be possible to link him to specific tribes, partly because so few Native Americans in the United States have had their genomes sequenced for comparison.
The recent publication of the Kostenki-14 genome, which has been described as morphologically Australoid, but appears to be genetically European should make us wary of interpreting phenotypes of early specimens in terms of the much later human populations. In the case of Europeans, it seems that the Caucasoid genetic lineage existed even before full Caucasoid morphology had evolved (at least in some specimens of Upper Paleolithic Europeans, as others had clear Caucasoid morphology).

I would not be surprised if the same was true for Native Americans, that is, the typical morphology of recent Native Americans was not present in their earliest predecessors, who, nonetheless, were part of the same evolving lineage of humans in the Americas. The Anzick-1 genome from the Clovis culture and several mtDNA results have not really turned up anything "exotic" in ancient inhabitants of the Americas, so it seems that the hypothesis of recent Native Americans being descended from a wave of people that replaced earlier inhabitants is losing ground with each new discovery.

January 14, 2015

Y chromosome super-fathers

This is a very exciting paper. Most of these lineages are so young that there are good chances that their founders were figures from history or mythology.

The most interesting one is DC2 which was also found in south Siberian Kurgans, belongs to haplogroup R1a1 and is given an age of 3,284 years by the authors (with some almost impossibly wide confidence intervals). Based on its distribution, and if a Bronze Age date is right, it is difficult to see in it anything other than a patrilineage that was present in Proto-Indo-Iranians.


European Journal of Human Genetics advance online publication 14 January 2015; doi: 10.1038/ejhg.2014.285

Y-chromosome descent clusters and male differential reproductive success: young lineage expansions dominate Asian pastoral nomadic populations

Patricia Balaresque et al.

High-frequency microsatellite haplotypes of the male-specific Y-chromosome can signal past episodes of high reproductive success of particular men and their patrilineal descendants. Previously, two examples of such successful Y-lineages have been described in Asia, both associated with Altaic-speaking pastoral nomadic societies, and putatively linked to dynasties descending, respectively, from Genghis Khan and Giocangga. Here we surveyed a total of 5321 Y-chromosomes from 127 Asian populations, including novel Y-SNP and microsatellite data on 461 Central Asian males, to ask whether additional lineage expansions could be identified. Based on the most frequent eight-microsatellite haplotypes, we objectively defined 11 descent clusters (DCs), each within a specific haplogroup, that represent likely past instances of high male reproductive success, including the two previously identified cases. Analysis of the geographical patterns and ages of these DCs and their associated cultural characteristics showed that the most successful lineages are found both among sedentary agriculturalists and pastoral nomads, and expanded between 2100 BCE and 1100 CE. However, those with recent origins in the historical period are almost exclusively found in Altaic-speaking pastoral nomadic populations, which may reflect a shift in political organisation in pastoralist economies and a greater ease of transmission of Y-chromosomes through time and space facilitated by the use of horses.

Link

SpaceMix preprint

bioRxiv http://dx.doi.org/10.1101/013474

A Spatial Framework for Understanding Population Structure and Admixture.

Gideon Bradburd, Peter L. Ralph, Graham Coop

Geographic patterns of genetic variation within modern populations, produced by complex histories of migration, can be difficult to infer and visually summarize. A general consequence of geographically limited dispersal is that samples from nearby locations tend to be more closely related than samples from distant locations, and so genetic covariance often recapitulates geographic proximity. We use genome-wide polymorphism data to build “geogenetic maps”, which, when applied to stationary populations, produces a map of the geographic positions of the populations, but with distances distorted to reflect historical rates of gene flow. In the underlying model, allele frequency covariance is a decreasing function of geogenetic distance, and nonlocal gene flow such as admixture can be identified as anomalously strong covariance over long distances. This admixture is explicitly co-estimated and depicted as arrows, from the source of admixture to the recipient, on the geogenetic map. We demonstrate the utility of this method on a circum-Tibetan sampling of the greenish warbler (Phylloscopus trochiloides), in which we find evidence for gene flow between the adjacent, terminal populations of the ring species. We also analyze a global sampling of human populations, for which we largely recover the geography of the sampling, with support for significant histories of admixture in many samples. This new tool for understanding and visualizing patterns of population structure is implemented in a Bayesian framework in the program SpaceMix.

Link

January 01, 2015

Y-chromosome tree bursts to leaf (Hallast, Batini, Zadik et al. 2014)

This is an extremely important study of Y-chromosome variation, the most intriguing part of which are the copious references to a yet to come manuscript:
Elsewhere (Batini C, Hallast P, Zadik D, Maisano Delser P, Benazzo A, Ghirotto S, Arroyo-Pardo E, Cavalleri GL, de Knijff P, Dupuy BM, Eriksen H, King TE, López de Munain A, López-Parra AM, Milasin J, Novelletto A, Pamjav H, Sajantila A, Tolun A, Winney B and Jobling MA, submitted.) we have described an NGS-based MSY phylogeny based on 5,996 SNPs ascertained in 334 human Y chromosomes comprising 17 population samples from Europe and the Near East, focused on illuminating the origins and histories of European patrilineages.
Anyway, the current paper is openly available, so do read it if you haven't already. Of interest to long-time readers of this blog is this bit:
Generally, the STRs perform poorly, giving a wide variety of TMRCAs for nodes with similar SNP-based dates, and correlation coefficients consistently below 0.6. Considering the variables described above: 1) ASD generally outperforms rho, and choice of rooting method (ancestral or modal) makes little difference. For rho, rooting through the ancestral haplotype performs much worse than through the modal haplotype; 2) removal of RM-YSTRs, and STRs showing repeat array complexity, does not have a major influence on relationships between SNP- and STR-based estimates of TMRCA, and the effects depend upon how the root is specified; and 3) the evolutionary STR mutation rate consistently overestimates, and the pedigree rate underestimates, the TMRCAs of nodes (fig. 4a). As expected, the pedigree mutation rate performs better for young nodes (less than 10 ka; supplementary table S6, Supplementary Material online), whereas the evolutionary rate performs better for older nodes.
Mol Biol Evol (2014) doi: 10.1093/molbev/msu327

The Y-Chromosome Tree Bursts into Leaf: 13,000 High-Confidence SNPs Covering the Majority of Known Clades

Pille Hallast, Chiara Batini, Daniel Zadik et al.

Many studies of human populations have used the male-specific region of the Y chromosome (MSY) as a marker, but MSY sequence variants have traditionally been subject to ascertainment bias. Also, dating of haplogroups has relied on Y-specific short tandem repeats (STRs), involving problems of mutation rate choice, and possible long-term mutation saturation. Next-generation sequencing can ascertain single nucleotide polymorphisms (SNPs) in an unbiased way, leading to phylogenies in which branch-lengths are proportional to time, and allowing the times-to-most-recent-common-ancestor (TMRCAs) of nodes to be estimated directly. Here we describe the sequencing of 3.7 Mb of MSY in each of 448 human males at a mean coverage of 51×, yielding 13,261 high-confidence SNPs, 65.9% of which are previously unreported. The resulting phylogeny covers the majority of the known clades, provides date estimates of nodes, and constitutes a robust evolutionary framework for analyzing the history of other classes of mutation. Different clades within the tree show subtle but significant differences in branch lengths to the root. We also apply a set of 23 Y-STRs to the same samples, allowing SNP- and STR-based diversity and TMRCA estimates to be systematically compared. Ongoing purifying selection is suggested by our analysis of the phylogenetic distribution of nonsynonymous variants in 15 MSY single-copy genes.

Link

Y Chromosome of Aisin Gioro: C3b2b1

Apart from the historical interest, this study might be useful to further calibrate the Y-chromosome molecular clock. The Y-SNP mutation rate was previously calibrated with a Chinese pedigree that went down to ~1800AD, and this is potentially much deeper.

arXiv:1412.6274 [q-bio.PE]

Y Chromosome of Aisin Gioro, the Imperial House of Qing Dynasty 

Shi Yan, Harumasa Tachibana, Lan-Hai Wei, Ge Yu, Shao-Qing Wen, Chuan-Chao Wang

(Submitted on 19 Dec 2014) House of Aisin Gioro is the imperial family of the last dynasty in Chinese history - Qing Dynasty (1644 - 1911). Aisin Gioro family originated from Jurchen tribes and developed the Manchu people before they conquered China. By investigating the Y chromosomal short tandem repeats (STRs) of 7 modern male individuals who claim belonging to Aisin Gioro family (in which 3 have full records of pedigree), we found that 3 of them (in which 2 keep full pedigree, whose most recent common ancestor is Nurgaci) shows very close relationship (1 - 2 steps of difference in 17 STR) and the haplotype is rare. We therefore conclude that this haplotype is the Y chromosome of the House of Aisin Gioro. Further tests of single nucleotide polymorphisms (SNPs) indicates that they belong to Haplogroup C3b2b1*-M401(xF5483), although their Y-STR results are distant to the "star cluster", which also belongs to the same haplogroup. This study forms the base for the pedigree research of the imperial family of Qing Dynasty by means of genetics.

Link

Western Eurasian mtDNA in modern Siberians

The eastern European mtDNA discussed in this article might be a remnant of the population of Proto-Europeoids that occupied Siberia even in Upper Paleolithic times (as the genome of the Mal'ta Upper Paleolithic Siberian has shown). However, the authors write:
Overall, the phylogeographic analysis strongly implies that the western Eurasian founders, giving rise to Siberian specific subclades, trace their ancestry only to the early and mid-Holocene, though some of genetic lineages may trace their ancestry back to the end of LGM. Importantly, we have not found the modern northern Asians to have western Eurasian genetic components of sufficient antiquity to indicate traces of pre-LGM expansions, that originated from the Upper Paleolithic industries present both in the southern Siberia and Siberian Arctic, and that date back to ~30 kya, well before the LGM [43]–[45].
If this is true, then probably the mysterious Mal'ta-like population did not have a lasting impact in Siberia.

The western Asia/Caucasus migration can't be attributed to farming expansions (because Siberia didn't have those), so it may very well be a genetic signature of the Bronze Age expansion of Indo-European languages (assuming it did not go there with occasional trade and intermarriage with later Eastern Europeans and Central Asians).

BMC Evolutionary Biology 2014, 14:217 doi:10.1186/s12862-014-0217-9

Western Eurasian ancestry in modern Siberians based on mitogenomic data

Miroslava Derenko et al.

Abstract

Background

Although the genetic heritage of aboriginal Siberians is mostly of eastern Asian ancestry, a substantial western Eurasian component is observed in the majority of northern Asian populations. Traces of at least two migrations into southern Siberia, one from eastern Europe and the other from western Asia/the Caucasus have been detected previously in mitochondrial gene pools of modern Siberians.

Results

We report here 166 new complete mitochondrial DNA (mtDNA) sequences that allow us to expand and re-analyze the available data sets of western Eurasian lineages found in northern Asian populations, define the phylogenetic status of Siberian-specific subclades and search for links between mtDNA haplotypes/subclades and events of human migrations. From a survey of 158 western Eurasian mtDNA genomes found in Siberia we estimate that nearly 40% of them most likely have western Asian and another 29% European ancestry. It is striking that 65 of northern Asian mitogenomes, i.e. ~41%, fall into 19 branches and subclades which can be considered as Siberian-specific being found so far only in Siberian populations. From the coalescence analysis it is evident that the sequence divergence of Siberian-specific subclades was relatively small, corresponding to only 0.6-9.5 kya (using the complete mtDNA rate) and 1–6 kya (coding region rate).

Conclusions

The phylogeographic analysis implies that the western Eurasian founders, giving rise to Siberian specific subclades, may trace their ancestry only to the early and mid-Holocene, though some of genetic lineages may trace their ancestry back to the end of Last Glacial Maximum (LGM). We have not found the modern northern Asians to have western Eurasian genetic components of sufficient antiquity to indicate traces of pre-LGM expansions.

Link

Ancient DNA from Di-qiang populations in the Xinjiang

American Journal of Physical Anthropology DOI: 10.1002/ajpa.22690

Ancient DNA reveals a migration of the ancient Di-qiang populations into Xinjiang as early as the early Bronze Age

Shi-Zhu Gao et al.

Xinjiang is at the crossroads between East and West Eurasia, and it harbors a relatively complex genetic history. In order to better understand the population movements and interactions in this region, mitochondrial and Y chromosome analyses on 40 ancient human remains from the Tianshanbeilu site in eastern Xinjiang were performed. Twenty-nine samples were successfully assigned to specific mtDNA haplogroups, including the west Eurasian maternal lineages of U and W and the east Eurasian maternal lineages of A, C, D, F, G, Z, M7, and M10. In the male samples, two Y chromosome haplogroups, C* and N1 (xN1a, N1c), were successfully assigned. Our mitochondrial and Y-chromosomal DNA analyses combined with the archaeological studies revealed that the Di-qiang populations from the Hexi Corridor had migrated to eastern Xinjiang and admixed with the Eurasian steppe populations in the early Bronze Age.

Link

Bias in estimators of archaic admixture

arXiv:1412.6691 [q-bio.PE]

Bias in Estimators of Archaic Admixture

Alan R. Rogers, Ryan J. Bohlender

(Submitted on 20 Dec 2014)

This article evaluates bias in one class of methods used to estimate archaic admixture in modern humans. These methods study the pattern of allele sharing among modern and archaic genomes. They are sensitive to "ghost" admixture, which occurs when a population receives archaic DNA from sources not acknowledged by the statistical model. The effect of ghost admixture depends on two factors: branch-length bias and population-size bias. Branch-length bias occurs because a given amount of admixture has a larger effect if the two populations have been separated for a long time. Population-size bias occurs because differences in population size distort branch lengths in the gene genealogy. In the absence of ghost admixture, these effects are small. They become important, however, in the presence of ghost admixture. Estimators differ in the pattern of response. Increasing a given parameter may inflate one estimator but deflate another. For this reason, comparisons among estimators are informative. Using such comparisons, this article supports previous findings that the archaic population was small and that Europeans received little gene flow from archaic populations other than Neanderthals. It also identifies an inconsistency in estimates of archaic admixture into Melanesia.

Link

Happy New Year 2015

Since I didn't get my wish for any ancient African DNA last year, I repeat it for this year as well.

December 09, 2014

"Ancient DNA: the first three decades" meeting papers

A bucketload of papers here. Some titles of interest:

  1. Where are the Caribs? Ancient DNA from ceramic period human remains in the Lesser Antilles
  2. Identification of kinship and occupant status in Mongolian noble burials of the Yuan Dynasty through a multidisciplinary approach
  3. The ancient Yakuts: a population genetic enigma
  4. Ancient mitochondrial DNA from the northern fringe of the Neolithic farming expansion in Europe sheds light on the dispersion process
  5. Mitochondrial DNA variation in the Viking age population of Norway
  6. Almost 20 years of Neanderthal palaeogenetics: adaptation, admixture, diversity, demography and extinction
  7. Screening ancient tuberculosis with qPCR: challenges and opportunities
  8. Parallel detection of ancient pathogens via array-based DNA capture
  9. Unravelling the complexity of domestication: a case study using morphometrics and ancient DNA analyses of archaeological pigs from Romania
  10. Ancient genomics
  11. Ancient population genomics and the study of evolution

December 06, 2014

African Genome Variation project paper

A choice quote:
To assess the effect of gene flow on population differentiation in SSA, we masked Eurasian ancestry across the genome (Supplementary Methods and Supplementary Note 6). This markedly reduced population differentiation, as measured by a decline in mean pairwise FST from 0.021 to 0.015 (Supplementary Note 6), suggests that Eurasian ancestry has a substantial impact on differentiation among SSA populations. We speculate that residual differentiation between Ethiopian and other SSA populations after masking Eurasian ancestry (pairwise FST = 0.027) may be a remnant of East African diversity pre-dating the Bantu expansion10.
I think this should be highlighted for a couple of reasons.

1. In too many papers to count, decreasing genetic diversity from East Africa was taken as evidence of an origin of H. sapiens in that locality and its expansion from there to Eurasia. This "East Africa=cradle of mankind" theory has, as far as I can tell, nothing really to stand on. Granted, the oldest anatomically modern human remains have been found in East Africa 200-150 thousand years ago. But, the fact that old sapiens have been found in East Africa and not elsewhere is easily explained by the excellent conditions for preservation (as opposed, e.g., deserts or rainforests of Africa or elsewhere), and by the extraordinary effort by palaeoanthropologists in that area. One also needs to overlook a century of physical anthropology that concluded that East Africa was a contact zone between Caucasoids and Sub-Saharan Africans. We now know that there is no deep lineage of humans in modern east Africans. Take out the Eurasian ancestry and only a paltry Fst=0.027 remains with other Sub-Saharan Africans, a fraction of the Fst between, say, Europeans and East Asians.

2. There has been enormous literature about phenotypic variation in Africans. The ultra-migrationism of old was replaced by ultra-selectionism that sought to explain every phenotypic marker of Eurasian admixture in Africa not as evidence of such admixture, but as a parallel process of evolution whereby some Africans tended to resemble some Eurasians not because of admixture but because of adaptation to similar environmental conditions.

But:
This suggests that a large proportion of differentiation observed among African populations could be due to Eurasian admixture, rather than adaptation to selective forces (Supplementary Note 6).
This study also confirms the presence of Eurasian admixture in the Yoruba
Our finding of ancient Eurasian admixture corroborates findings of non-zero Neanderthal ancestry in Yoruba, which is likely to have been introduced through Eurasian admixture and back migration, possibly facilitated by greening of the Sahara desert during this period13, 14.

Nature (2014) doi:10.1038/nature13997

The African Genome Variation Project shapes medical genetics in Africa

Deepti Gurdasani, Tommy Carstensen, Fasil Tekola-Ayele, Luca Pagani, Ioanna Tachmazidou, et al.

Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterization of African genetic diversity is needed. The African Genome Variation Project provides a resource with which to design, implement and interpret genomic studies in sub-Saharan Africa and worldwide. The African Genome Variation Project represents dense genotypes from 1,481 individuals and whole-genome sequences from 320 individuals across sub-Saharan Africa. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across sub-Saharan Africa. We identify new loci under selection, including loci related to malaria susceptibility and hypertension. We show that modern imputation panels (sets of reference genotypes from which unobserved or missing genotypes in study sets can be inferred) can identify association signals at highly differentiated loci across populations in sub-Saharan Africa. Using whole-genome sequencing, we demonstrate further improvements in imputation accuracy, strengthening the case for large-scale sequencing efforts of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa.

Link

December 02, 2014

Remains of Richard III identified

From the paper:
Four of the modern relatives were found to belong to Y-haplogroup R1b-U152 (x L2, Z36, Z56, M160, M126 and Z192)13, 14 with STR haplotypes being consistent with them comprising a single patrilinear group. One individual (Somerset 3) was found to belong to haplogroup I-M170 (x M253, M223) and therefore could not be a patrilinear relative of the other four within the time span considered, indicating that a false-paternity event had occurred within the last four generations. 
... 
In contrast to the Y-haplotypes of the putative modern relatives, Skeleton 1 belongs to haplogroup G-P287, with a corresponding Y-STR haplotype. Thus, the putative modern patrilinear relatives of Richard III are not genetically related to Skeleton 1 through the male line over the time period considered. However, this is not surprising, given an estimated average false-paternity rate of ~1–2% (refs 12, 17, 18). The putative modern relatives and Richard III are related through a male relative (Edward III) four generations up from Richard III (Fig. 1a and Supplementary Fig. 2), and a false-paternity event could have happened in any of the 19 generations separating Richard III and the 5th Duke of Beaufort, on either branch of the genealogy descending from Edward III. Indeed, even with a conservative false-paternity rate18 (see Supplementary Methods) the chance of a false-paternity occuring in this number of generations is 16%.

Nature Communications 5, Article number: 5631 doi:10.1038/ncomms6631

Identification of the remains of King Richard III

Turi E. King et al.

Abstract

In 2012, a skeleton was excavated at the presumed site of the Grey Friars friary in Leicester, the last-known resting place of King Richard III. Archaeological, osteological and radiocarbon dating data were consistent with these being his remains. Here we report DNA analyses of both the skeletal remains and living relatives of Richard III. We find a perfect mitochondrial DNA match between the sequence obtained from the remains and one living relative, and a single-base substitution when compared with a second relative. Y-chromosome haplotypes from male-line relatives and the remains do not match, which could be attributed to a false-paternity event occurring in any of the intervening generations. DNA-predicted hair and eye colour are consistent with Richard’s appearance in an early portrait. We calculate likelihood ratios for the non-genetic and genetic data separately, and combined, and conclude that the evidence for the remains being those of Richard III is overwhelming.

Link

November 25, 2014

E-M81 in Morocco

Hum Biol. 2014 May;86(2):105-12.

Phylogeography of e1b1b1b-m81 haplogroup and analysis of its subclades in morocco.

Reguig A, Harich N, Barakat A, Rouba H.

Abstract

In this study we analyzed 295 unrelated Berber-speaking men from northern, central, and southern Morocco to characterize frequency of the E1b1b1b-M81 haplogroup and to refine the phylogeny of its subclades: E1b1b1b1-M107, E1b1b1b2-M183, and E1b1b1b2a-M165. For this purpose, we typed four biallelic polymorphisms: M81, M107, M183, and M165. A large majority of the Berber-speaking male lineages belonged to the Y-chromosomal E1b1b1b-M81 haplogroup. The frequency ranged from 79.1% to 98.5% in all localities sampled. E1b1b1b2-M183 was the most dominant subclade in our samples, ranging from 65.1% to 83.1%. In contrast, the E1b1b1b1-M107 and E1b1b1b2a-M165 subclades were not found in our samples. Our results suggest a predominance of the E1b1b1b-M81 haplogroup among Moroccan Berber-speaking males with a decreasing gradient from south to north. The most prevalent subclade in this haplogroup was E1b1b1b2-M183, for which diffferences among these three groups were statistically significant between central and southern groups.

Link

Paternal lineages and languages in the Caucasus

An interesting new study on Y chromosome and languages in the Caucasus. The distribution of haplogroups is on the left. The authors make some associations of haplogroups with language families:

  • R1b: Indo-European
  • R1a: Scytho-Sarmatian
  • J2: Hurro-Urartian
  • G2: Kartvelian

Hum Biol. 2014 May;86(2):113-30.

Human paternal lineages, languages, and environment in the caucasus.

Tarkhnishvili D1, Gavashelishvili A1, Murtskhvaladze M1, Gabelaia M1, Tevzadze G2.

Abstract

Publications that describe the composition of the human Y-DNA haplogroup in diffferent ethnic or linguistic groups and geographic regions provide no explicit explanation of the distribution of human paternal lineages in relation to specific ecological conditions. Our research attempts to address this topic for the Caucasus, a geographic region that encompasses a relatively small area but harbors high linguistic, ethnic, and Y-DNA haplogroup diversity. We genotyped 224 men that identified themselves as ethnic Georgian for 23 Y-chromosome short tandem-repeat markers and assigned them to their geographic places of origin. The genotyped data were supplemented with published data on haplogroup composition and location of other ethnic groups of the Caucasus. We used multivariate statistical methods to see if linguistics, climate, and landscape accounted for geographical diffferences in frequencies of the Y-DNA haplogroups G2, R1a, R1b, J1, and J2. The analysis showed significant associations of (1) G2 with wellforested mountains, (2) J2 with warm areas or poorly forested mountains, and (3) J1 with poorly forested mountains. R1b showed no association with environment. Haplogroups J1 and R1a were significantly associated with Daghestanian and Kipchak speakers, respectively, but the other haplogroups showed no such simple associations with languages. Climate and landscape in the context of competition over productive areas among diffferent paternal lineages, arriving in the Caucasus in diffferent times, have played an important role in shaping the present-day spatial distribution of patrilineages in the Caucasus. This spatial pattern had formed before linguistic subdivisions were finally shaped, probably in the Neolithic to Bronze Age. Later historical turmoil had little influence on the patrilineage composition and spatial distribution. Based on our results, the scenario of postglacial expansions of humans and their languages to the Caucasus from the Middle East, western Eurasia, and the East European Plain is plausible.

Link (pdf)

November 07, 2014

Genome of Kostenki-14, an Upper Paleolithic European (Seguin-Orlando, Korneliussen, Sikora, et al. 2014)

A new paper in Science reports on the genome of Kostenki-14 (K14), an Upper Paleolithic European from Russia. This is now the third oldest Homo sapiens for which we have genetic data, after Ust'-Ishim (Siberia, 45 thousand years), Tianyuan (China, 40 thousand years), and now Kostenki (European part of Russia, 37 thousand years). Of these three genomes, the Ust'-Ishim is both the highest coverage and earliest (Siberia is the gift that keeps on givin'), Tianyuan only has its chromosome 21 known, and K14, a complete 2.42x coverage sequence (and, apparently, good teeth, after all these years; left).

The publication of the Tianyuan genome showed that populations related to East Asians and Oceanians existed in the world 40 thousand years ago. So, models based on modern humans that put the split of East Asians from Europeans to a much more recent time period were basically wrong (more on this a little below). The Ust'-Ishim genome showed that populations basal to both East Asians and Europeans existed in the world 45 thousand years ago. So, either East Asians and Europeans hadn't gone along their different paths yet, or, if they had, Ust'-Ishim happened to be a side branch and not the major East Asian and European lineages.

K14 may not be the older Upper Paleolithic human, but as of this writing it is the only Upper Paleolithic European that has been published so far, the next ones being the Loschbour, Motala, and La Brana Mesolithic Europeans who who have about 1/5 of its age. The new paper shows that K14 was definitely European (or more correctly West Eurasian or Caucasoid), as it was more similar to modern Europeans than to East Asians or other non-West Eurasian populations. Thus, the morphological description of the sample as "Australoid" by some early anthropologists did not reflect its ancestral makeup. Also, this proves that Caucasoids existed 37,000 years ago, which most physical anthropologists would believe, but it is nice to have direct confirmation. This pushes the lower bound from 24,000 years ago (because MA-1 was West Eurasian according to the results of Raghavan et al.). It will be nice to push the lower bound further to the past as there are much older bones (and plenty of teeth) from earlier Upper Paleolithic Europeans.

But there is a slight kink in the story, as K14 also belonged to Y-haplogroup C which is predominantly East Asian/Ocenian/Native American today. So, maybe there is some distant link to these populations in its ancestry. But, there is definitely a link to much more recent Europeans: the tiny percentage of living Europeans who have preserved K14's Y-chromosomal type (some of which were doubtlessly told a few years back that they were descendants of Genghis Khan, before the phylogenetic structure of C was known), the La Brana hunter-gatherer from Mesolithic Spain, as well as Neolithic Europeans from Hungary.

The authors of the current paper also date the date of Neandertal admixture to 54 thousand years. This seems very compatible with the finding of between 50 and 60 thousand years by Fu et al. (2014) based on the Ust'-Ishim genome (which is both earlier and better, so the chunks of Neandertal ancestry in it are probably be longer and more well-defined).

The authors propose the following model for how various populations are related to each other:


This model is not formally tested, but at least it seems to derive Europeans as a 3-way mixture that is basically identical to that of Lazaridis et al., with some relabeling of populations (MHG=WHG and NEOL=EEF).

The model also includes Yeniseian Siberians as a mixture of MHG and East Asians (although it does not include actual East Asians). It's strange that Yeniseians apparently are given no ANE ancestry but only WHG/MHG. Both Raghavan et al. and Lazaridis et al. mentioned that ancestry related to MA-1 in living Siberians is diminished, but none at all?

The major new finding of this paper, however, is that K14 had Basal Eurasian ancestry, which was first proposed for EEF from Germany 7,000 years ago, so now it postulated for Russian hunter-gatherers 37,000 years ago. I don't think many archaeologists would derive European farmers from Russia (Russia is actually one of the last places in Europe that became agricultural). So, maybe the hunter-gatherers from Russia had Basal Eurasian ancestry and this wasn't limited to the ancestors of the EEF? If they did, it's strange that Loschbour, La Brana, MA-1, Ust'-Ishim, Swedish Mesolithic (and maybe KO1?) didn't have it. So, either Kostenki was very unique or there is an alternative explanation for its strangeness.


The evidence for the Basal Eurasian ancestry in K14 is summarized in the figure above in bullet point (b).

  • The statistic D(Mbuti, East Asia; HG, K14) is less than 0. So, there's some link between HG and East Asians. Is this because of Basal Eurasian admixture in K14 or due to some admixture between Caucasoids and Mongoloids after the time of K14? (this might cause the lower dates of European-East Asian splits alluded to above).
  • The statistic D(Mbuti, East Asia; NEOL, K14) is 0. So, East Asians don't "prefer" either Neolithic Europeans (NEOL) or K14. I guess the value of this statistic depends on how much Basal Eurasian the different populations have and what's the relationship between East Asians, K14, and the non-Basal Eurasian part in K14.
  • Finally, "NEOL component for K14 in ADMIXTURE". I think they are referring to the "Middle East" component (right). This may be Basal Eurasian ancestry, or maybe because K14 is so old, it pre-dates the European/Middle Eastern divide and its ancestry isn't attracted to either Europe or the Middle East, so it gets ancestry from both (and many other colors besides).

It is fascinating how many new questions are both answered and raised each time a new genome gets published (and there has been a constant stream of these over the last couple of years).

Science DOI: 10.1126/science.aaa0114

Genomic structure in Europeans dating back at least 36,200 years

Andaine Seguin-Orlando1,*, Thorfinn S. Korneliussen1,*, Martin Sikora1, et al.

The origin of contemporary Europeans remains contentious. We obtain a genome sequence from Kostenki 14 in European Russia dating to 38,700 to 36,200 years ago, one of the oldest fossils of Anatomically Modern Humans from Europe. We find that K14 shares a close ancestry with the 24,000-year-old Mal’ta boy from central Siberia, European Mesolithic hunter-gatherers, some contemporary western Siberians, and many Europeans, but not eastern Asians. Additionally, the Kostenki 14 genome shows evidence of shared ancestry with a population basal to all Eurasians that also relates to later European Neolithic farmers. We find that Kostenki 14 contains more Neandertal DNA that is contained in longer tracts than present Europeans. Our findings reveal the timing of divergence of western Eurasians and East Asians to be more than 36,200 years ago and that European genomic structure today dates back to the Upper Paleolithic and derives from a meta-population that at times stretched from Europe to central Asia.

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