The Indo-European invasion of the Baltic

In some recent posts, I showed that South Asian populations (North Indian Brahmins, South Indian Brahmins) can be seen as mixtures of West Eurasian and South Indian populations, but also that West Eurasians (Bulgarians, Greeks, Armenians, and French) can be seen as mixtures of South Asian and Sardinian populations.

This may seem strange, but can be explained if we understand how f3-statistics and rolloff actually work. These methods do not require pure or unadmixed ancestral populations, but exploit allele frequency differences in the reference populations together with either (i) allele frequencies in the mixed population, in the case of f3-statistics, or (ii) admixture linkage disequilibrium in the mixed population, in the case of rolloff.

If a and b are allele frequencies in two ancestral populations A and B that mix, then:

• The frequency of a will shift towards b if A experiences gene flow from B
• The frequency of a will randomly shift if A experiences gene flow from an "outgroup" population
• The frequency of a will shift towards b if A experiences gene flow from a third population that is geographically and genetically intermediate between A and B

An application to the Europe-South Asia cline

I took the following set of populations, and calculated all 1,365 possible f3-statistics:

"FIN30"         "Lithuanians"   "Russian"       "Pathan"        "Balochi"       "North_Kannadi" "Polish_D"      "Russian_D"     "Mixed_Slav_D"  "Bulgarian_D"   "Serb_D"        "Ukrainian_D"   "Belorussian"   "Bulgarians_Y"  "Ukranians_Y"

In the following table, I report the lowest Z-scores for each target population (third column). So, for example, Polish_D can be seen as a mixture of Lithuanians and Balochi. Only negative scores are indicative of admixture. I highlight in bold the significant negative scores (Z less than -3)


Lithuanians North_Kannadi FIN30 0.001606 0.000259 6.193 280043
Ukrainian_D Belorussian Lithuanians 0.00078 0.000299 2.614 268493
Lithuanians North_Kannadi Russian -0.002738 0.000248 -11.045 279965
North_Kannadi Polish_D Pathan -0.006959 0.000229 -30.344 280220
North_Kannadi Bulgarians_Y Balochi -0.003636 0.000246 -14.781 281604
Pathan Ukrainian_D North_Kannadi 0.033802 0.000623 54.237 271858
Lithuanians Balochi Polish_D -0.001171 0.000178 -6.581 279519
Lithuanians Pathan Russian_D -0.001829 0.000166 -11.026 280658
Lithuanians Pathan Mixed_Slav_D -0.001715 2e-04 -8.594 277635
Lithuanians Balochi Bulgarian_D -0.001247 0.000313 -3.979 272342
Lithuanians Balochi Serb_D -0.00091 0.000377 -2.416 270807
Lithuanians Balochi Ukrainian_D -0.002222 0.000358 -6.211 270399
Lithuanians Balochi Belorussian -0.000897 0.00027 -3.325 273076
Balochi Polish_D Bulgarians_Y -0.001198 0.000185 -6.481 279632
Lithuanians Balochi Ukranians_Y -0.001727 0.000187 -9.236 278677

It is clear, that what I have described holds here: European populations appear like mixtures of Lithuanians and South Asians; conversely, South Asian populations appear like mixtures of Europeans and North Kannadi.

This does not mean that the populations that appear unadmixed (FIN30, Lithuanians, North_Kannadi, and Serbs) are in fact so, for at least two reasons:

1. The f3 statistic confirms, but does not reject the presence of admixture; in particular, it fails to find real admixture in highly drifted populations
2. The f3 statistics exploits allele frequency correlations between populations: but the North Kannadi and Lithuanians/Finns occupy opposite ends of the studied cline, so their lack of signal of admixture may be due to the non-existence of populations that are even more unadmixed than themselves.

In the case of South Indians, we are completely sure that this is the case. Reich et al. (2009) managed to show this not because there are any unadmixed Ancestral South Indians (ASI) left, but because they exploited the existence of the Onge, an isolated group from the Andaman Islands that was a sister group to the ASI. So, we can be fairly sure that southern Indians themselves have West Eurasian-like admixture, even the ones that are at the end of the West Eurasia-South India cline on its southern end.

The problem is: there is no isolated group of unadmixed Europeans left in existence that might serve a similar proxy function as the Onge did for South Asians.

Enter Pickrell et al. (2012) to the rescue. In that paper, the authors studied admixture in the Khoe-San of South Africa. Now, many of the Khoe-San sub-groups appeared to be admixed, but the "Juj'hoan North" population appeared to be at the "end of the cline": it's impossible to detect admixture in them using alelle frequency differences, because, quite simply, there are no populations that are less unadmixed than them: they're as pure descendants of "Ancestral Bushman" as exist on the earth today.

But, the clever thing is, that we don't have to detect admixture only using allele frequency differences, but also using admixture LD, i.e., by exploiting the correlation between linkage disequilibrium (the co-inheritance of physically separated markers on a chromosome) and allele frequency differences between populations. Pickrell el al. were able to do this not by conjuring up a more unadmixed population than the "Juj'hoan North" one available to them, but by splitting up that population, and using one half to find allele frequency differences, and the other half to detect admixture LD.

Admixture LD signal in Lithuanians

Using the aforementioned idea, I set out to see whether Lithuanians, who occupy the European end of the Europe-South Asia cline present such a signal of admixture LD. I used the Lithuanian_D sample from the Dodecad Project and the Balochi HGDP sample as reference populations (to calculate allele frequency differences), and the Behar et al. (2010) Lithuanians for admixture LD. There were only ~300k SNPs usuable in this set, but sufficient to detect the signal of admixture LD:

The admixture time estimate is 200.350 +/- 61.608 generations, or 5,810 +/- 1790 years. This is not very precise, probably because of the small number of SNPs and individuals used, but it certainly points to the Neolithic-to-Bronze Age for the occurrence of this admixture. The date is certainly reminiscent of the expansion of the Kurgan culture out of eastern Europe, or, the later Corded Ware culture of northern Europe.

So, it may well appear that at least some of the people participating in these groups of cultures, were indeed influenced by the Indo-Europeans as they expanded from their West Asian homeland. These intruders mixed with eastern Europeans who vacillated during the late Neolithic between a northern Europeoid pole akin to Mesolithic hunter gatherers from Gotland and Iberia, and a widely dispersed Sardinian-like population that is in evidence at least in the Sweden-Italian Alps-Bulgaria triangle. The gradual appearance of non-mtDNA U related lineages in Siberia and Ukraine is most likely related to this phenomenon.

It would seem that the Proto-Indo-Europeans mixed with different substrata in the four directions of their expansion: Sardinian-like people in southern Europe, Lithuanian-like people in northern Europe, South Indian-like people in South Asia, and East Eurasians in Siberia and east central Asia. Extant groups are descendants of divergent Neolithic population groups, brought closer together (genetically) because of variable admixture with the PIE population and its early offshoots.

Conclusion

There are mutual signals of admixture across a Europe-South Asia cline: Europeans appear to be mixed with South Asians, and South Asians appear to be mixed with Europeans. The simplest explanation for this pattern involves expansion of a third, geographically and genetically intermediate population that affected both Europe and South Asia. We can use the signal of admixture LD to prove that this expansion affected some of the most unadmixed populations in Europe (e.g., Lithuanians), just as it did the most unadmixed populations of India (e.g., Dravidians).

It will be interesting to use these techniques to study signals of admixture in other "end of the line" populations such as Sardinians, South Indians, etc.

UPDATE I (rolloff analysis of Poles):

I have carried out rolloff analysis of my 25-strong Polish_D sample using Lithuanians and Pathans as references:

The signal is fairly distinct, and corresponds to 149.296 +/- 38.783 generations or 4330 +/- 1120 years. I am guessing that either the different reference population (Pathans vs. Balochi), or, more likely the increased number of target individuals (25 vs. 10) have contributed to the narrowing down of the uncertainty. It will be interesting to explore this signal further with more population pairs.

UPDATE II (rolloff analysis of Finns):

I have also used the 1000 Genomes Finnish sample (FIN) in a similar manner as Lithuanians, using 15 individuals to estimate allele frequency differences, and 15 ones for admixture LD, and using the Pathans as a South Asian reference population. There is a clear signal of admixture:

This dates to 104.967 +/- 14.797 generations, or 3,040 +/- 430 years. Finland came under the influence of both Europeans (and likely Indo-Europeans) during the Bronze Age period (a mixture of Battle Axe with local Comb Ceramic seems to have occurred), as well as likely non-European (and likely Uralic) intrusions during the same time frame, as part of the Seima-Turbino phenomenon. It will be interesting to repeat this analysis with an East Eurasian reference population to isolate potential signals of admixture dating to either the Comb Ceramic or Seima-Turbino episodes of migration.

(Note; added Oct 14): I carried out rolloff analysis using Nganassans as suggested in the above paragraph here.

UPDATE III (rolloff analysis of Ukrainians):

I have used the Yunusbayev et al. sample of Ukrainians, and estimated its admixture time using Lithuanians and Balochi as reference populations:

The admixture time estimate is 191.078 +/- 35.079 generations, or 5,540 +/- 1,020 years. It seems very similar to that in Lithuanians, with a smaller standard error, perhaps on account of either the larger number of SNPs or larger number of individuals.

It is tempting to associate this admixture signal with the Maikop culture which appeared at around this time. Assuming that North_European/West_Asian (or Lithuanian-like and Balochi-like) gene pools existed north and south of the Pontic-Caspian-Caucasus set of geographical barriers, then the Maikop culture which shows links to both the early Transcaucasian culture and those of Eastern Europe would have been an ideal candidate region for the admixture picked up by rolloff to have taken place. There are, of course, other possibilities.

UPDATE IV (rolloff analysis of Lithuanians with Pathan reference):

I repeated the first analysis of this post, but this time, I used Pathans, rather than Balochi as a reference population:

The admixture time estimate of 217.501 +/- 51.170 generations, or 6,310 +/- 1,480 years appears to be similar with the original estimate of 5,810 +/- 1790 years, so it does not appear that the use of Balochi or Pathan as a reference population much affects this result.

Indo-European genetic signatures in an Orcadian and a Lithuanian

In the Bronze Age Indo-European invasion of Europe, I argued that:

• A West_Asian genetic component is missing from ancient DNA sampled from Europe as recently as ~5,000 years ago.
• This component exists at appreciable frequencies in modern Europeans, reaching minima in non-Indo-European Basques and Finns.
• It is likely that the West_Asian component manifested itself in Europe post-5kya, during the Copper and Bronze Ages, and was associated with the bearers of Indo-European languages.

Of course, the West_Asian component is an abstraction created from a study of modern populations. To better understand the identity of this component, I undertook a simple experiment using the (not yet released) K5c and K8c calculators of the Dodecad Project. The are equivalent to the weac2 and K7b calculators released so far by the Project, but make use of the new Pagani et al. (2012) data on East Africa, hence the appearance of an "East_African" component at K=7 pushing back the appearance of the West_Asian component to K=8.

K5c captures the "West Eurasian cline" between the Near East and Europe, and includes the following components:

• East_Eurasian
• South_Asian
• Atlantic_Baltic
• Near_East
• African

We can say that the Atlantic_Baltic corresponds to northern Caucasoids, while the Near_East one to southern Caucasoids.

K8c includes the following components:

• Atlantic_Baltic
• West_Asian
• Siberian
• Southern
• South_Asian
• West_African
• East_Asian
• East_African

This differs from the previous one in the appearance of the Siberian and East_African components, as well as the aforementioned West_Asian one within West Eurasia.

Naturally the question arises: what can we say about the origin of West_Asian ancestry in modern Europeans? How is it related to other populations? How is it related to the northern and southern Caucasoids?

To answer these questions, I isolated an Orcadian individual (HGDP00794) and used the DIYDodecad byseg mode to construct a local ancestry map of this individual with sliding windows 500 SNP long, advanced by 50 SNPs.

In essence, this procedure assigns ancestry to local regions of the genome, and can hence be used to identify, e.g., regions with an excess of West_Asian or any other component.

I decided to use an Orcadian for this purpose, since Orcadians are Indo-European speakers from northwestern-most Europe who can be reasonably thought to have minimum admixture in historical times from groups other than (i) the pre-Indo-European substratum, (ii) Celto-Germanic superstratum which dominates western Europe.

Over 3,126 total segments, I calculated the correlation between the K5c and the K8c components:

It is clear that the K=8 West_Asian segments of the Orcadian individual correspond to the K=5 South_Asian (+0.36) and Near_East (+0.29) segments. 

The negative correlation with the K=5 Atlantic_Baltic (-0.4) component further indicates that in genomic regions where the Orcadian has West_Asian segments, there is a deficiency of Atlantic_Baltic ancestry; we can be fairly sure that these segments are not the result of common partial descent of Orcadians and West Asians from a northern Caucasoid population.

I have also repeated the above experiment, but with a Lithuanian individual (GSM536635). Lithuanians are surrounded by Indo-European and Finno-Ugric speakers, and are also relatively unlikely to have experienced other gene flow in more recent times:

The same general pattern emerges, with the K=8 West_Asian segments corresponding to K=5 Near Eastern and South Asian segments.

CONCLUSION

Chunks of DNA in an Orcadian and a Lithuanian that are labelled West_Asian tend to be related to populations of the Near East and South Asia. 

It seems fairly clear that a post-5kya link between the North Atlantic and the Indian subcontinent admits to a single parsimonious explanation: the expansion of the Indo-Europeans out of their West Asian homeland during the Copper and Bronze Ages.

ESHG 2011 abstracts are online

From here. I didn't find much of interest this year, except a long-overdue look at Bulgarian Y-chromosomes but with not a very informative abstract.

Y-Chromosome genetic variation of modern Bulgarians
S. Karachanak et al.

To date, Bulgarian Y chromosomes have been studied only in macrogeographic context or in the lineage-based approach. Therefore, in order to comprehensively characterize Bulgarian Y-chromosome variation, we have performed high-resolution phylogenetic analysis of 812 healthy,unrelated Bulgarian males and compared the results with Y-chromosome data from other Eurasian populations.
The genotyping of 60 biallelic markers was performed in hierarchical order by RFLP and DHPLC analyses. The position of Bulgarians among other populations was visualized by Principal Component (PC) analysis.
About 80% of the total genetic variation in Bulgarians falls within haplogroups E-M35, I-M170, J-M172, R-M17 and R-M269. This finding shows that the Bulgarian haplogroup profile is congruent with those described for most European populations.
Among the prehistoric events marked by the observed haplogroups, the greatest contribution comes from the range expansion of local Mesolithic foragers triggered by adoption of agriculture introduced by a cadre of Near Eastern farmers. The Bulgarian Y chromosome gene pool also bears signals of the recolonization from different glacial refugia, the spread of agriculture from the Near East and the expansion of early farmers along the Central and East European river basins.
As for the interpopulation analysis, similarly to mtDNA, Bulgarians belong to the cluster of European populations, still being slightly distant from them. Bulgarians are distant from Turks (despite geographical proximity), Arabic and Caucasus populations and Indians. These trends in the PCA graph likely reflect not only prehistoric, but also more recent demographic events that have shaped the Y chromosome structure of modern Bulgarians.

An abstract on Yakuts seems to report the link between the Altaic-Turkic Yakut and the Altaic-Tungusic Evenk that I also discovered recently.

Autosomal and uniparental genetic diversity of the populations of Sakha (Yakutia): Implications for the peopling of Northeast Eurasia
S. A. Fedorov et al.

Sakha Autonomous Republic occupies a quarter of Siberian total land area in its northeastern part, is an important region for understanding the colonization of the Northern Eurasia by anatomically modern humans. To characterize the genetic variation in Sakha both the haploid mitochondrial DNA (mtDNA) and Y chromosomal as well as diploid autosomal loci (650 000 SNPs) of genome were analyzed in five native populations of Sakha (Yakuts, Evenks, Evens, Dolgans and Yukaghirs).
While striking prevalence of Y chromosome haplogroup N1c in gene pool differentiates Yakuts from other populations, the mtDNA and autosomal analyses demonstrate genetic similarity of all native populations of Sakha, in particular Yakuts and Evenks. The results also demonstrate closest genetic proximity of the populations of Sakha with southern Siberians. Both mtDNA and autosomal analyses reveal deep genetic discontinuity between Siberian and Beringian populations. MtDNA haplogroups A2 and G1b, prevalent in Beringian populations, are either minor or even absent in Sakha, where haplogroups C and D dominate. Autosomal analysis also differentiates Beringian populations from those of Sakha. Our results support the scenario that the territory of Sakha was colonized from the regions west and eastward of Lake Baikal with only minor gene flow from Lower Amur/Southern Okhotsk region and/or Kamchatka.

An abstract on Lithuanian Y-chromosomes

The place of the population of Lithuania between Northern and Eastern Europe: Y chromosome analysis
I. Uktverytė et al.

The population of Lithuania is constituted of 6 dialectal groups which form two major ethno-linguistic groups known as Aukštaitish and Žemaitish, both speaking Baltic languages of Indo-European family. Neighbouring Finno-Ugric (Northern and Eastern Europe), Slavonic (Eastern Europe) and Germanic (Northern Europe) populations surrounding the Baltic sea region influenced historical formation of Lithuanian ethno-linguistic groups. Analysis of the Lithuanian population genetic composition helps to understand the origin, history and place among other populations.
Y chromosome analysis was performed for 301 individuals from 6 dialectal groups. 25 SNPs were genotyped (TaqMan) to determine Y haplogroup and 17 STR were analysed to determine haplotype for each individual. Most frequent haplogroups in the population of Lithuania are R1a1a (42.2%, R1a1a1g compose 8.97% in studied population) and N1c1 (40.5%) and less frequent haplogroups are R1b1b1, I1, I2a, E1b1b1 (<5% each). AMOVA showed no statistically significant differences between two major ethno-linguistic groups Aukštaitish and Žemaitish (among groups p-value=0.897, among population within groups p-value=0.194, within populations p-value=0.282 based on 10100 permutations). MDS of genetic distances based on Y-biallelic markers showed that Lithuanians are closer to Latvian and Estonian populations than to Slavic populations (European part of Russia, Poland, Ukraine, Belorussia, stress=0.029). According to the frequencies of haplogroups, no statistically significant differences between ethno-linguistic groups were detected (p>0.05), moreover, MDS analysis sets the population of Lithuania between Northern and Eastern European populations.

An abstract on Sardinian population structure.

A genome-wide analysis of Sardinian population structure
M. Steri et al.

Sardinia is particular attractive for human genetic studies, being one of the larger isolated populations and thus suitable for large-scale studies. Several attempts have been made to explore its genetic structure, but they either analyzed a large set of markers in very few samples or thousands of individuals at specific loci. Here we genotyped 2,615 individuals with the Affymetrix 6.0 array. Samples were recruited from the north, south and central east areas of the Island, and initially considered as 3 distinct populations. Genotype calling was performed with Birdseed-v2, considering all samples as a unique cluster to avoid batch effects. Subsequently, we applied standard filters for samples and SNP quality, and used IBD sharing to detect, and discard, hidden relatives. Using principal component analysis, we identified outliers and reassigned each individual accordingly. An analysis of molecular variance indicated that only 0.21% of the variability could be attributable to inter-population variation (Fst=0.002), confirming a lack of large-scale substructure. We thus considered the Sardinians as a unique sample. Compared to HapMap3 populations, as expected, higher similarity was observed with Tuscany and CEPH samples (Fst=0.005 and 0.010, respectively). A genome-wide search for SNPs highly differentiated between Sardinians and these European populations confirmed the specialness of HLA and LCT regions, and also showed elevated Fst values (>0.27) at the CR1 gene, known to be related to malaria severity. We are now integrating sequencing data of many individuals to provide a more comprehensive analysis of variants in addition to the common SNPs in current genotyping platforms.

A major new study on Arabian mtDNA

Phylogeographic analyses; mitochondrial DNA; Arabian Peninsula
V. Fernandes et al.

Phylogeographic analyses of mitochondrial DNA (mtDNA) provide insights into modern human evolution. In recent years, worldwide studies of contemporary mtDNAs have indicated that modern humans left Africa ~60,000-70,000 years ago along the “southern coastal route”, across the Red Sea and via the Arabian Peninsula. Yet no obvious signs of the passage though Arabia have been found in genetics and archaeology fields. The aims of this work are to seek for possible mtDNA relicts of the initial dispersal from Africa in Arabia and to investigate the origins of lineages that arrived later. We are doing this by sequencing the complete mtDNA molecule (~16,568 bp) from unclassified lineages (referred to as the paraphyletic clusters L3*, N* and R*) and poorly studied haplogroups within the Eurasian macrohaplogroup N, which is predominant in Arabian populations today (86% in Saudi Arabia, 66% in Yemen and 79% in Dubai), in 90 samples from Dubai, Yemen, North/East Africa, the Near East and Europe. Our results will allow to test hypotheses about the settlement of the Arabian Peninsula.

Eastern European ancestry in New Hampshire

There have been a bunch of studies on Hispanic Americans, Native Americans, African Americans, but very little work on European Americans (if we exclude the perennial fascination of the genetics community with Ashkenazi Jews and some studies which included European Americans of known European parentage).

This is one of the first studies I've seen where the objective was to look at a geographically definite population of European Americans and study its diverse origins in Europe itself. While there are many European Americans whose ancestry is no mystery at all (because their ancestors arrived within memory), there are also large numbers of them with much older ancestry, and these should sometime become the object of study, both for their own sake, but also because they may represent a separate evolutionary road of their ancestral European gene pool.

The STRUCTURE result, beautified by CLUMPP, is really fascinating. Unlike most studies where sub-population labels of clustered individuals are put on the chart, in this case individuals do not necessary report a single ancestry, so cannot be put on a single population label. Yet it is really evident that "European Americans from New Hampshire" can be broken down to several groups with a distinctive ancestry.

From the paper:

Bayesian clustering conducted using the structure software revealed distinct subpopulations, with the highest and most reliable probabilities between a K of 5 and 7. The bar plots are shown for K = 2 to K = 8 from the CLUMPP software (aligns multiple runs of structure) from 10 runs at each K (Figure 1a). As expected, individuals in the sample appear highly admixed; however distinct populations are discernible. The FST's increase consistently as K increases, with the average FST's for K = 4 to K = 7 around the level of “little genetic differentiation” as defined by Wright (approx. 0.05) (Figure 1c,d) [22]. The admixture values increase for lower K's, but begin to drop at K = 6 to values between 0.6–0.7 (Table S2). In selecting the most correct K, parsimony is an important consideration, i.e. that the simpler answer tends to be correct. Though there may be some validity to further subdividing the groups, the most statistically consistent and the most parsimonious K based on the structure output is K = 6. Further analysis using the ancestral data is used to describe the groupings and lends support to our selection of K = 6.

...

These results suggest that genetic population structure is detectable in a highly admixed US population and that this structure correlates with self-reported ancestry. To our knowledge, this is the first time such an investigation has uncovered a strong link between structure and ancestry in what would otherwise be assumed to be a homogeneous US state where most individuals are of European ancestry. Our data indicate that that admixture has not eliminated the genetic structure found within Europe, and descendants of the Russian, Polish and Lithuanian immigrants remain genetically distinct from the rest of the population and are closely related to one another.

...

Exploratory analysis revealed that among the ancestries, those reported by at least five individuals were: American Indian (n = 32), Austria (n = 5), Belgium (n = 5), Canadian Indian (n = 14), Canada (n = 113), Czech Republic (n = 5), England (n = 355), Finland (n = 7), French-Canadian (n = 54), France (n = 173), Germanic (countries where Germanic languages spoken) (n = 5), Germany (n = 110), Greece (n = 9), Ireland (n = 218), Italy (n = 41), Jewish (n = 6), Lithuania (n = 12), Canadian Maritime Provinces (n = 6), Netherlands (n = 25), Poland (n = 44), Russia (n = 13), Scotland (n = 157), Sweden (n = 24), Switzerland (n = 7), UK (n = 11), US (n = 42), Wales (n = 24).

PLoS ONE doi:10.1371/journal.pone.0006928

Genetic Population Structure Analysis in New Hampshire Reveals Eastern European Ancestry


Chantel D. Sloan et al.

Abstract

Genetic structure due to ancestry has been well documented among many divergent human populations. However, the ability to associate ancestry with genetic substructure without using supervised clustering has not been explored in more presumably homogeneous and admixed US populations. The goal of this study was to determine if genetic structure could be detected in a United States population from a single state where the individuals have mixed European ancestry. Using Bayesian clustering with a set of 960 single nucleotide polymorphisms (SNPs) we found evidence of population stratification in 864 individuals from New Hampshire that can be used to differentiate the population into six distinct genetic subgroups. We then correlated self-reported ancestry of the individuals with the Bayesian clustering results. Finnish and Russian/Polish/Lithuanian ancestries were most notably found to be associated with genetic substructure. The ancestral results were further explained and substantiated using New Hampshire census data from 1870 to 1930 when the largest waves of European immigrants came to the area. We also discerned distinct patterns of linkage disequilibrium (LD) between the genetic groups in the growth hormone receptor gene (GHR). To our knowledge, this is the first time such an investigation has uncovered a strong link between genetic structure and ancestry in what would otherwise be considered a homogenous US population.

Link

Central European farmers not descended from local hunter-gatherers (Bramanti et al. 2009)

This is the real power of DNA: the topic of whether central European farmers were the result of demic diffusion from the southeast or indigenous hunter-gatherers who adopted the agricultural economy has been endlessly debated in archaeological circles.

We are finally in a position to give an answer to the question, and the answer is in favor of the diffusionist camp and against the idea of acculturation by local hunter-gatherers. Surprisingly, modern Central Europeans do not appear to be a simple hunter-gatherer/farmer mix, suggesting that even later events (post-Neolithic) have shaped their genetic diversity.

This study is also a powerful argument against the idea of genetic continuity across long time spans. Most ancient DNA studies so far have reached a similar conclusion. Thus, it also destroys the supposed justification for continuity from Paleolithic Europe to modern times that early mtDNA work (of the Daughters of Eve variety) has proposed, hand in hand with the hunter acculturation hypothesis.

The paper is covered in National Geographic:

Central and western Europe's first farmers weren't crafty, native hunter-gatherers who gradually gave up their spears for seeds, a new study says.

Instead, they were experienced outsiders who arrived on the scene around 5500 B.C. with animals in tow—and the locals apparently didn't roll out the welcome wagon.

"Within a few generations, all the farmers—probably coming from southeast Europe—moved into central Europe bringing their culture, [livestock], and everything," Joachim Burger, a molecular archaeologist at the University of Mainz in Germany, said via email.

The finding is based on analysis of genetic material in the skeletal remains of ancient hunter-gatherers and early farmers found in Germany, Lithuania, Poland, and Russia—though farming is thought to have reached areas as far west as western France during the period of rapid expansion, about 7,500 years ago.

The study goes against a long-standing idea that Europe's first farmers were former hunter-gatherer populations that had settled the region after the last ice age, about 10,000 years ago.

Perhaps, the thinking went, the hunter-gatherers had observed farming practices during their travels or had learned from neighbors.

Instead, the researchers found, the hunter-gatherers and the early farmers remained segregated, according to the study, to be published tomorrow in the journal Science.

And the press release:

Analysis of ancient DNA from skeletons suggests that Europe's first farmers were not the descendants of the people who settled the area after the retreat of the ice sheets. Instead, the early farmers probably migrated into major areas of central and eastern Europe about 7,500 years ago, bringing domesticated plants and animals with them, says Barbara Bramanti from Mainz University in Germany and colleagues. The researchers analyzed DNA from hunter-gatherer and early farmer burials, and compared those to each other and to the DNA of modern Europeans. They conclude that there is little evidence of a direct genetic link between the hunter-gatherers and the early farmers, and 82 percent of the types of mtDNA found in the hunter-gatherers are relatively rare in central Europeans today.

For more than a century archaeologists, anthropologists, linguists, and more recently, geneticists, have argued about who the ancestors of Europeans living today were. We know that people lived in Europe before and after the last big ice age and managed to survive by hunting and gathering. We also know that farming spread into Europe from the Near East over the last 9,000 years, thereby increasing the amount of food that can be produced by as much as 100-fold. But the extent to which modern Europeans are descended from either of those two groups has eluded scientists despite many attempts to answer this question.

Now, a team from Mainz University in Germany, together with researchers from UCL (University College London) and Cambridge, have found that the first farmers in central and northern Europe could not have been the descendents of the hunter-gatherers that came before them. But what is even more surprising, they also found that modern Europeans couldn't solely be the descendents of either the hunter-gatherer alone, or the first farmers alone, and are unlikely to be a mixture of just those two groups. "This is really odd", said Professor Mark Thomas, a population geneticist at UCL and co-author of the study. "For more than a century the debate has centered around how much we are the descendents of European hunter-gatherers and how much we are the descendents of Europe's early farmers. For the first time we are now able to directly compare the genes of these Stone Age Europeans, and what we find is that some DNA types just aren't there - despite being common in Europeans today."

Humans arrived in Europe 45,000 years ago and replaced the Neandertals. From that period on, European hunter-gatherers experienced lots of climatic changes, including the last Ice Age. After the end of the Ice Age, some 11,000 years ago, the hunter-gatherer lifestyle survived for a couple of thousand years but was then gradually replaced by agriculture. The question was whether this change in lifestyle from hunter-gatherer to farmer was brought to Europe by new people, or whether only the idea of farming spread. The new results from the Mainz-led team seems to solve much of this long standing debate.

"Our analysis shows that there is no direct continuity between hunter-gatherers and farmers in Central Europe," says Prof Joachim Burger. "As the hunter-gatherers were there first, the farmers must have immigrated into the area."

The study identifies the Carpathian Basin as the origin for early Central European farmers. "It seems that farmers of the Linearbandkeramik culture immigrated from what is modern day Hungary around 7,500 years ago into Central Europe, initially without mixing with local hunter gatherers," says Barbara Bramanti, first author of the study. "This is surprising, because there were cultural contacts between the locals and the immigrants, but, it appears, no genetic exchange of women."

The new study confirms what Joachim Burger´s team showed in 2005; that the first farmers were not the direct ancestors of modern European. Burger says "We are still searching for those remaining components of modern European ancestry. European hunter-gatherers and early farmers alone are not enough. But new ancient DNA data from later periods in European prehistory may shed also light on this in the future."

And from archaeology.about.com:

A new study published by Barbara Bramanti and colleagues in Science Express on September 4, 2009, supports what some scholars have suspected all along—that the LBK likely were an in-migration of people from the Balkans, and that they did not, initially anyway, do much mixing at all with the earlier inhabitants of Europe.

Bramanti and her colleagues compared the mitochondrial DNA from 20 central European Upper Paleolithic, Mesolithic and Neolithic hunter-gatherers to that from 25 Neolithic farmers and 484 modern Europeans, spanning an age range from about 13,400 to 2,300 BC. The data shows that the early farmers and hunter-gatherers were from distinctively different populations.

This paper follows up on and to a degree contradicts with the hypothesis of an earlier paper that looked only at mtDA of the Neolithic farmers. That study (Haak et al. 2005) discovered that the farmers had a distinctive difference between the current residents of Europe, and hypothesized that that meant that the hunter-gatherers might have been more like the modern inhabitants, and thus, the LBK would have been only a minor component.

The earlier paper by Haak et al. they refer to.

(More technical details once I read the full paper)

UPDATE:

Pre-farming populations seem to have been dominated by mtDNA haplogroup U:

it is intriguing to note that 82% of our 22 hunter-gatherer individuals carried clade U (fourteen U5, two U4, and two unspecified U-types; table 1).

The hunter-gatherers had no N1a -which was a signature of early farmers in the Haak et al. paper- or of haplogroup H, the most common mtDNA haplogroup in Europeans today. The only non-U types in hunter-gatherers were all from the Ostorf site and included haplogroups T2e, J, and K.

The farmers:

In a previous study, we showed that the early farmers of Central Europe carried mainly N1a, but also H, HV, J, K, T, V, and U3 types (11, 12). We found no U5 or U4 types in that early farmer sample.

UPDATE I:

It is important to note the implications of this study: the most certain conclusion is that Neolithic farmers in Central Europe are very sharply differentiated from the Paleolithic-Mesolithic populations. This is clear evidence in favor of the diffusionist idea, since the acculturation hypothesis predicts that the mtDNA of the early farmers would be roughly that of the pre-farming population that picked up the new technology.

However, the evidence of this paper also contradicts the plain demic diffusion hypothesis. According to this hypothesis, farmer genes are gradually replaced by hunter genes as the farming economy spreads, because in each step there is a mix of farmer-indigenous populations which go on to colonize regions beyond the frontier. This is not what appears to have happened. Rather, it seems the farmers moved across Europe with very little interaction with pre-farmers. A long period of no contact between the LBK and foragers is actually supported by archaeology. I have termed this type of diffusion the "skipping stone":

In the Skipping Stone model, farmers move out in search of new territories before they have started to blend with the local foragers; the genetic impact of the initiators of the movement is preserved.

The great speed of the Linearbandkeramik farmers was also experienced by farmers who spread across the Mediterranean. The spread of agriculture in Europe does not appear to have been a slow process of interaction between farmer and forager, but rather a blitz by the first farmers, followed later, after the spread had already occurred by admixture with some of the foragers that remained.

We must also be certain not to jump into conclusions about the relative contributions of farmer and forager in the modern gene pool. Clearly both the idea of a predominantly "Paleolithic" and a predominantly "Neolithic" gene pool is problematic; such continuity is not really evident. However, the reasons for the discontinuity up to the present may be manifold: e.g., later population movements into Europe, or natural selection changing the gene pool without subsequent change of population.

What we do know is this: first farmers were not local foragers who abandoned the old ways for the new ones. Amalgamation between farmer and forager did not happen quickly as the farming economy spread. Finally it did happen, of course, and either because (i) there were few foragers in the mix, or (ii) their mtDNA was selected against, modern central Europeans have very little mitochondrial descent from the earliest European populations.

PS: Natural selection against forager mtDNA is not very outlandish. For example, a severe reduction of U5a1 and U5b haplogroup in Britain from ancient to modern times has been observed, which could potentially mark another data point in a process of selection against that haplogroup over time.

My personal guess is that both demography and selection may have played a role in the marginalization of hunter-gatherer mtDNA . LBK farmers were already 3 thousand years removed from the earliest agriculturalists of the Near East, so it is conceivable that they had evolved an mtDNA gene pool adapted to the new lifestyle that outcompeted the indigenous European one. But, the long period of isolation from foragers may mean that only farmer mtDNA benefited from the demographic boom associated with the new economy, and by the time relations between the two groups warmed up, the relatively few newcomers already dwarfed the older population demographically.

UPDATE II (Sep 4):

To understand the magnitude of the difference between farmers and hunter-gatherers, the authors calculate their Fst=0.163, which can be compared with a maximum value of 0.0327 among modern Europeans and 0.133 for modern Eurasians from Europe to Australia. Subsequently, the authors test the hypotheses of (a) continuity between hunter-gatherers and farmers, and (b) continuity between hunter-gatherers and modern Central Europeans, rejecting both.

This isn't very surprising in the light of the anthropological evidence in favor of diffusion of farmers from the Near East and against the acculturation hypothesis presented recently by Pinhasi et al. The very close relationship of the LBK skulls and their proximity to samples from Nea Nikomedeia in Greece and Catal Hoyuk in Anatolia contrasts with the Mesolithic populations.

UPDATE III (Sep 21):

Some possible anthropological evidence for post-LBK infusion into Central Europe:

Mesolithic Europeans display considerable variation in humero-clavicular and brachial indices yet none approach the extreme "hyper-polar" morphology of LBK humans from the MESV. In contrast, Late Neolithic and Early Bronze Age peoples display elongated brachial and crural indices reminiscent of terminal Pleistocene and "tropically adapted" recent humans. These marked morphological changes likely reflect exogenous immigration during the terminal Fourth millennium cal BC.

Science doi:10.1126/science.1176869

Genetic Discontinuity Between Local Hunter-Gatherers and Central Europe’s First Farmers

B. Bramanti et al.

Following the domestication of animals and crops in the Near East some 11,000 years ago, farming reached much of Central Europe by 7,500 years before present. The extent to which these early European farmers were immigrants, or descendants of resident hunter-gatherers who had adopted farming, has been widely debated. We compare new mitochondrial DNA (mtDNA) sequences from late European hunter-gatherer skeletons with those from early farmers, and from modern Europeans. We find large genetic differences between all three groups that cannot be explained by population continuity alone. Most (82%) of the ancient hunter-gatherers share mtDNA types that are relatively rare in Central Europeans today. Together, these analyses provide persuasive evidence that the first farmers were not the descendants of local hunter-gatherers but immigrated into Central Europe at the onset of the Neolithic.

Link

ASHG 2008 abstracts

Just a sample of abstracts that I found interesting from the upcoming meeting of the American Society of Human Genetics.

Strong linkage disequilibrium for the frequent GJB2 35delG mutation in the Greek population.

Up to forty percent of autosomal recessive, congenital, severe to profound hearing impairment cases result from mutations in the GJB2 gene. The 35delG mutation accounts for the majority of mutations detected in Caucasian populations and represents one of the most frequent disease mutations identified so far. Some previous studies have assumed that the high frequency of the 35delG mutation reflects the presence of a mutational hot spot, whilst other studies support the theory of a common founder. Greece is amongst the countries presenting the highest frequency of the 35delG mutation (3.5%), and a recent study raised the hypothesis of the origin of this mutation in ancient Greece. We genotyped 60 Greek deafness patients homozygous for the 35delG mutation for six single nucleotide polymorphisms (SNPs) and two microsatellite markers, mapping within or flanking the GJB2 gene, as compared to 60 Greek hearing controls. A strong linkage disequilibrium was found between the 35delG mutation and the DNA markers at distances of 34 kb on the centromeric and 90 kb on the telomeric side of the gene, respectively. A comparison of the present findings with those of a previous study from Belgium, UK and USA, demonstrated a common haplotype reflecting the common founder. Our study supports the hypothesis of a founder effect and we further propose that ethnic groups of Greek ancestry could have propagated the 35delG mutation, as evidenced by historical data beginning from the 15th century BC.

Detection of population substructure among Jews and a north/south gradient within Ashkenazi Jews using 32 STR markers.

Understanding and detecting population substructure are critical issues. Using 32 autosomal STR markers and the program STRUCTURE we demonstrated differentiation between Ashkenazi (AJ) (N=135) and Sephardic (SJ) (N=226) Jewish populations in the form of Northern and Southern European genetic components (AJ north 73%, south 22%, SJ north 32%, south 61%) and a significant relationship between latitude of grandparental country of origin (GCO) and percent north/south genetic component in AJ. Notably, we revealed substructure among Jews (and among European Americans (EA)) using a small STR panel, only when additional samples representing major continental populations (African American, EA, Asian) were included in analyses. Further, negative RIS (-0.035) indicates recent admixture in individuals with both SJ and AJ parents (N=38). RIS is a measure of inbreeding adapted from FIS for STR markers. Negative RIS indicates allelic variation within individuals greater than expected under random mating, i.e., excess heterozygosity due to outbreeding. Although geographic patterns are seen in the average north/south percent assignment values between groups as defined by AJ or SJ, grandparental world region of origin, or GCO, within each group there is high variability among individual assignment values. Thus, even based on data from a small marker set, AJ is not a homogeneous population. The north/south gradient in AJ may be a reflection of the pre-existing north/south gradient in European host populations (recently shown in other studies using large numbers of SNPs) with which Jews admixed slowly. We also demonstrate the utility of including purported parental populations when attempting to detect population substructure within closely related populations.

Mutation meltdown of mitochondrial DNA and Neanderthal extinction.

There is emerging evidence that mitochondrial DNA (mtDNA) plays and integral role in the evolution of the human species. Although contentious, recent phylogenetic studies of modern humans implicate genetic variation of mitochondrial DNA (mtDNA) as a major factor underpinning the climatic adaptation of across the globe. Greater sequence diversity in the MTATP6 gene in arctic populations led to the idea that specific mtDNA polymorphisms cause subtle uncoupling of the respiratory chain, with the subsequent generation of additional heat being adaptive in northern climes. Our knowledge of mtDNA and its affect on adaptability may help us to understand how modern humans have survived their early ancestors. Here, we characterise the mtDNA of one of these extinct hominids. Neanderthals are the closest hominid relatives of modern humans, who up until 30,000 years ago coexisted in Europe and western Asia. Recently, over 1Mb of DNA was successfully extracted and characterised from the Vi-80 Neanderthal fossil. We reanalysed 2,705 base pairs of mtDNA in order to examine the hypothesis that mitochondrial dysfunction contributed to the Neanderthals demise. We identified thirty-two nucleotide differences from the modern human mtDNA reference sequence and by treating the Vi-80 as a diagnostic sample leads us to the conclusion that sequence variants that are highly likely to be artifacts, and a large proportion of the remaining mutations could be due to nuclear pseudogene amplification. We did identify a potentially deleterious variation; however more study may be needed to ascertain the effect of mitochondrial dysfunction on Neanderthal survival.

Early Siberian Maternal Lineages in the Tubalar of Northeastern Altai Inferred from High-Resolution Mitochondrial DNA Analysis

At the hight of the last glaciation (~18 kya) Siberians were confined to the southern strongholds, which were areas of continuous occupation, and where immediate ancestors of the Uralic, Kettic and Altaian language groups differentiated. To better understand the evolutionary relationships between the earlier and contemporary Siberians, we focused on the northern Altaic prehistory preserved in the mtDNA diversity of the Tubalar, until recently representing a typical hunting-gathering population. The present study includes 139 Tubalar. All mtDNAs were subjected to high-resolution SNP analysis, followed by complete sequencing of selected mtDNA samples. We showed that the core of the Tubalar genetic makeup proved to be a mixture of west (H8, U4b, U5a1, and X2e) and east Eurasian (A and B1) haplogroups derived from macrohaplogroup N, and Siberian derivatives of the macrohaplogroup M identifiable by subhaplogroup-specific mutations. For example, among the 36 Tubalar mtDNA samples that belong to haplogroup D, 10 (28%) harbored diagnostic markers of the subhaplogroup D3a2a shared with the Chukchi and Eskimos. This finding verified at the complete sequence level we attributed to ancient link between early Siberians, who underwent pronounced differentiation in the Altai-Sayan region, and some of the Eskimo tribes. A comparison of the mtDNA data generated through the course of this study with published complete sequences has contributed essentially to parsimonious phylogenetic structure of mtDNA evolution in west Siberia. Specifically, northeastern Altai appears to be a good candidate for the ancestral homeland of the haplogroup U4b, which is apparently ancient European. For some haplogroups, such as X2e, the relatively recent arrival to the Altai region is more likely.

Sex-specific gene flow between Pygmy and non-Pygmy populations

Cultural traditions and preferences may drive sex-specific gene flow among human populations. We have examined sex-specific gene flow between Mbuti Pygmies, a hunter-gather population, and surrounding agriculturist groups, the Alur, Hema, and Nande, which all reside in Central Africa. We used 18 lineage-defining Y chromosome SNPs and HVS1 mitochondrial DNA sequence information to examine patterns of gene flow among these groups. Mbuti Pygmy males have more diverse Y chromosome lineages (Mbuti Pygmy [n = 28]: = 0.229; Alur [n = 10]: 0.193; Hema [n = 18]: 0.178; Nande [n = 15]: 0.090) and slightly less mtDNA diversity than neighboring groups (0.020, 0.023, 0.025, 0.022 in Mbuti Pygmy, Alur, Hema, and Nande groups, respectively). The majority of Mbuti Pygmy males have a Y haplotype characteristic of Mbuti Pygmies (B2b); however, more than 30% of Pygmy males exhibit Y haplotypes associated with Bantu-speaking agricultural populations (E3a lineage). Conversely, no agriculturist males exhibit Y haplogroups associated with Mbuti Pygmy populations but instead have derived Y haplogroups characteristic of Bantu agriculturalists (E2, E3a). Pairwise FST was calculated among all populations using Y haplogroup frequency and HVS1 mtDNA sequence data. YDNA and mtDNA FST values between Mbuti Pygmy and non-Pygmy groups (Alur, Hema, and Nande) were 0.278, 0.355, and 0.217 (for YDNA) and 0.088, 0.239 and 0.217 (for mtDNA), respectively. A Mantel test between pairwise FST matrices showed no significant correlation ((r = 0.27; p 0.35), which indicates that patterns of genetic differentiation differ between Y chromosome SNPs and mtDNA sequence patterns. These results also suggest no emigration of Mbuti Pygmy Y chromosomes into surrounding groups but immigration of non-Mbuti Pygmy Y chromosomes into the Mbuti Pygmy population.

Population Structure in Mongolia from a Mitochondrial DNA Perspective.

Mongolia has experienced a complex series of demographic movements over the past 10-20 millennia that have shaped the patterns of its modern human genetic variation. However, modern populations in Mongolia have not been extensively studied for DNA diversity, nor has the genetic contribution of Mongolians to the gene pools of contemporary populations in Southeast Asia and Oceania been fully resolved. Archaeological evidence from as early as the late Neolithic suggests the presence of both West and East Eurasian cultures in this region. Later demographic movements involving the emergence of the Mongolian and later Manchu Empires have further convoluted Mongolias population structure. To clarify the complex population history of Mongolia, we analyzed variation in the mtDNAs of 190 individuals from several Mongolian ethnic groups, including the Uriankhai, Zakhchin, Derbet, Khoton and Khalkha. We screened all samples for phylogenetically informative coding region SNPs and sequenced HVSI to assess control region variation in them. Our data suggest that the mtDNA diversity present in our population is consistent with the general pattern of variation observed in East Asia, with the most frequent haplogroups being C, D and G. Haplogroup variation in Mongolian ethnic groups reveals considerable maternal diversity with a predominance of basal M types. Interestingly, the Mongolians also possessed West Eurasian haplogroups, such as H, J and K, which are not commonly observed in East Asia, even at low frequencies. The main ethnic group in Mongolia, the Khalkha, was highly variable with respect to mtDNA haplotypes in comparison with the other ethnic groups, and clearly distinct from the Khoton and Zakhchin, as evidenced by distance measures. Overall, these data provide insights into the origins and affinities of these populations, their relationships with East Asian groups and neighboring Turkic speaking groups, including indigenous Altaians, and their possible role in the peopling of the Americas.

Allocation of YSTR Microvariant Alleles to Y-Chromosome Binary Haplogroups.

Y-chromosome short tandem repeat (YSTR) loci are used extensively in studies of population substructure, temporality of population dynamics, and forensic identification. The occurrence of non-consensus YSTR alleles, such as unusually short alleles or partial insertion/deletion events (microvariants), have been used successfully as indicators of common ancestry among YSTR haplotypes, exposing further levels of phylogenetic substructure with restricted geographic distributions. However, the high variability of STR loci can potentially lead to false associations due to homoplasy (ie, recurrent mutation). Thus, YSTR haplotypes are best interpreted within the context of the binary marker defined Y-chromosome phylogeny. To identify YSTR microvariant alleles potentially useful for elucidating further phylogenetic substructure within binary haplogroups, we have assessed the haplogroup affiliation of microvariant alleles found at informative frequencies in public YSTR databases for the following YSTR loci: DYS385, DYS392, DYS441, DYS446, DYS447, DYS449 and DYS464. We report haplogroup affiliations for each variant allele and geographic origins of representative samples.

L1c2a, the (African) Haplogroup With The Longest Mitochondrial Genome!

Haplotypes derived from the maternally-inherited mitochondrial DNA (mtDNA) control region are often employed as a first step in determining phylogenetic-relevant samples that could be selected for additional coding region testing. Using the currently defined world mtDNA haplogroup tree, researchers can assign these haplotypes to specific branches, paying particular attention to novel mutations that could assist in identifying new subclades. During a recent survey of the nearly 58000 mtDNA control region haplotypes currently present in the publicly accessible Sorenson Molecular Genealogy Foundation database, we observed a small number of mtDNAs (n=16) characterized by the presence of unusually long insertions of up to 200 bases. A small subset of these particularly long mtDNA haplotypes shared an identical insertion of 15 bases. Genealogical analysis combined with haplogroup prediction confirmed that these haplotypes shared a common African origin. Additionally, based on the pedigree data gathered, we determine the donors were not closely related. Moreover, through the analysis of complete mtDNA sequences, we conclude that the newly defined haplogroup is most likely of recent origin. As reported in this study, insertions of more than 10 bps are quite rare in the general population and in the published literature, thus providing an interesting case work in population and possibly future disease studies.

Mitochondrial DNA footprints in modern Mongolia.

Although Mongolia is one of the most sparsely populated countries in the world, it is located at a pivotal crossroad between the four corners of Asia (including the well-known Silk Road) and has been characterized throughout history by events that greatly added to its current cultural and ethnic diversity. Among these, perhaps one of the most significant happening was the ambitious expansion strategy employed by Mongolias most prominent personality, Genghis Khan, whose empire eventually stretched across all of modern-day China, a portion of modern Russia, Southern Asia, Eastern Europe and the Middle East. In 2007, through a well-planned collection effort, researchers at the Sorenson Molecular Genealogy Foundation and the National University of Mongolia were able to gather over 3,000 DNA samples, informed consents, and genealogical data throughout the country of Mongolia, including samples from 21 distinct tribal or ethnic populations. All the samples were sequenced for the three hypervariable segments of the mitochondrial DNA (mtDNA) control region to assess the genetic composition of modern Mongolia. The most common mtDNA haplotypes are typical of haplogroup C, which is frequent throughout Eastern Asia. However, nearly 40% of the observed mtDNA lineages are of Western Eurasian origin, including a significant frequency (~7%) of haplogroup H - the most common in Europe. The high prevalence of Western Eurasian lineages could be a remnant from Genghis Khans conquering efforts, trade and cultural exchanges along the Silk Route. To assess the extent of recent gene flow that could account for the elevated levels of Eurasian haplogroups within Mongolian populations, we have examined genealogical data of samples representative of Western Eurasian haplogroups.

Y chromosome microsatellite haplotypes in the Hutterite founders.

The current population of >12,000 Schmiedeleut Hutterites are descendants of 38 male founders who were born between 1700 and 1830 in Europe. Only 12 of these founders, each with a unique surname, have living male descendants related through male-only lineages. DNA samples were available in our laboratory for 75 male descendants of 11 of the 12 founders, accounting for 673 independent paternal meioses. We genotyped 9 microsatellite loci, which included a mean of 6.8 (range 2-23) males per lineage to evaluate potential relationships between the founders. Fourteen different haplotypes were identified, with an average of 3.5 (range 1-8) pairwise differences between haplotypes. All descendants within each of 9 lineages had identical Y haplotypes. Descendents of two of these lineages, 2 and 10, had the same haplotype despite different surnames, suggesting possible relatedness between the founders of these two lineages. Descendants of two lineages, 6 and 11, each carried three distinct haplotypes. Within each of these lineages the haplotypes differed from the ancestral haplotype by one repeat size at two loci. Additional male descendants in lineages 6 and 11 were then genotyped for the discrepant microsatellites, confirming the presence of three Y haplotypes each in lineages 6 and 11. The one mutation arose at each of four loci: DYS388, DYS389II, DYS390, DYS393. Three mutations were gains of one repeat; it was not possible to determine if the fourth mutation was a gain or loss of one repeat. The ancestral haplotypes in these two lineages are identical at four microsatellite loci; the alleles at the other five loci differ by one repeat size. The average mutation rate at these 9 loci was 0.00066 (95% CI 0.00015-0.0013), similar to other estimates. These data suggest that the founders of lineages 2 and 10 may have been related through paternal lines and that surnames do not strictly correspond to unique Y chromosomes. Moreover, certain ancestral haplotypes (i.e., those in lineages 6 and 11) may be more prone to mutation. Supported by NIH grants HD21244 and HL085197.

Genetic History of human populations of East African inferred from mtDNA and Y chromosome analyses.

Evidence from genetic, paleobiological, and archaeological studies suggest that Africa, especially East Africa, is most likely to be the cradle of the modern human species. Despite this fact, very little is currently known about genetic diversity in African populations in general, and East African populations in particular. Genetic data demonstrate that the patterns of genetic variation in East African populations are complex. All four major language families spoken in Africa (Afro-Asiatic, Nilo-Saharan, Niger-Kordofanian, and Khoisan) are found in the region. As part of a large study of population genetic diversity of East and Northeast Africa, we examined Y chromosome genetic diversity (to ascertain paternal lineages) as well as mitochondrial genetic diversity (to ascertain maternal lineages) in 1200 - 1500 individuals from ~ 40 Tanzanian, Sudanese, and Kenyan populations. For the Y chromosome analysis, we genotyped 60 UEPs (analyzed in a hierarchical manner to construct haplotypes) in a total of ~1500 male individuals. In order to infer ages of lineages and migration patterns, we further genotyped the individuals for 16 Y chromosome microsatellites. For the mtDNA analysis, we sequenced the mitochondrial D-loop in a total of 1200 individuals from the same populations, and for 200 individuals, we did complete mitochondrial genome sequencing. We compare our results with published results of studies from other parts of Africa and the Middle East. Our results indicate that East African populations have some of the most ancestral Y chromosome and mtDNA lineages in Africa, suggesting that they may have been an ancient source of dispersion throughout Africa. Additionally, we find evidence for ancient geneflow between East Africa and the Middle East. We also ascertained the effect of the Bantu-expansion and signature of recent migration of Cushitic-speaking groups originating from Ethiopia on peopling of East Africa.

Analysis of mtDNA and Y-chromosome haplogroups in Mexican Mestizos and Amerindian groups.

The Mexican population is mainly conformed by Mestizos, individuals with a genetic background consisting of Amerindian, European and African contributions. Genetic heterogeneity in Mexicans results from a complex demographic history that started with the peopling of North and Central America about 15,000 yrs ago, including the settlement of at least 60 different indigenous groups in Mexico, regional differences in admixture dynamics after colonization by Spaniards in the XVI century, epidemics and migration. Y chromosome-specific and mitcohondrial (mt) DNA polymorphisms are useful to help understand the genetic structure and history of human populations, due to their uniparental inheritance and lack of recombination. In order to refine the portrait of genetic variability derived from the Mexican Genome Diversity Project, we are characterizing maternal and paternal lineages participating in admixture. For this we included genotypic data from 163 mt SNPs and 123 Y chromosome SNPs present in the Illumina Human1M chip of 450 individuals, 300 mestizos from six states located in different regions: Northern, Central and Southern; and 150 individuals from different Amerindian groups (Tepehuanes, Zapotecos and Mayas). With this information, we are measuring genetic diversity using Fst and AMOVA analysis. Admixture analysis includes average and individual ancestral contribution estimates using autosomal SNPs. Initial results show that in our Mestizo sample, 88% of the mt haplogroups are Amerindian (A, B, C or D), and the rest includes European and African lineages. We have identified differences in proportions of each haplogroup in both Mestizos and Amerindians. Knowledege about the distribution of mt and Y-chromosome haplogroups in Mexican Mestizos and Amerindian groups, will generate valuable information to better understand genetic relationships between Mexicans and other Latin American populations. In addition, it may contribute to strengthen analysis in association studies of common complex diseases.

The origin of Native Americans from a mitochondrial DNA viewpoint.

America, the last continent to be colonized by modern humans, is characterized by an extraordinary linguistic and cultural diversity. Until recently, it was generally believed that starting around 13,500 years ago, the first Paleo-Indians arrived from Beringia, passing through an interior ice-free corridor in western North America, and spread rapidly all the way to Tierra del Fuego. Today, we realize that the peopling of the Americas involved a much more complex process. As for the maternally transmitted mitochondrial DNA (mtDNA), it has been clear since the early nineties that Native Americans could be traced back to four major maternal lineages (haplogroups) of Asian affinity. These were initially named A, B, C and D, and are now termed A2, B2, C1 and D1. More than 95% of living Native Americans belong to these four haplogroups, which can be considered pan-American, because they are shared by North, Central and South American populations. Later, five additional maternal lineages were discovered and named X2a, D2, D3, C4c, and D4h3. These less common or rare haplogroups are restricted only to some Native American populations or geographic areas and bring the overall number of Native American mtDNA lineages to nine. Our comprehensive overview of the four pan-American branches of the mtDNA tree suggests a scenario with a human entry and spread into the Americas from Beringia about 20,000 years ago, and preliminary data raise the possibility that the uncommon five Native American haplogroups might have marked additional migratory events from Asia or Beringia. Overall, through a combined analysis of modern and ancient Native American mtDNA, we are making an effort for reconstructing the complex pre-Columbian history at both macro- and micro-geographic levels.

Identifying genes affecting normal variation in human facial features using admixed populations.

Seven selection-nominated candidate genes (COL11A1, LMNA, FGFR1, FGFR2, TRPS, BRAF, FLNA) known to be involved in Mendelian craniofacial dysmorphologies and to have high allele frequency differences between West African and European populations were tested for admixture linkage to normal facial feature traits. The sample consists of 254 subjects (n=131 African Americans, n=123 Brazilians) of West African and European genetic ancestry. Each individual was genotyped at 176 ancestry informative markers (AIMs), which allowed for proportional estimation of genetic ancestry from four parental populations and adjustments for admixture stratification.
3D images of faces were acquired using the 3dMDface imaging system. 3D coordinate data were collected from 22 landmarks placed on each image using the 3dMDPatient software. The 231 possible pairwise landmark distances were scaled to the geometric mean and then analyzed using Euclidean Distance Matrix Analysis.
We used both ANOVA and ADMIXMAP to control for admixture stratification and to test for associations between the 231 pairwise landmark distances and 183 AIMs, using sex, height and BMI as covariates. We used a four-population model (West African, European, East Asian, and Native American).
There is a strong concordance between the ANOVA and ADMIXMAP results. Many landmark distances, particularly on the mouth and nose, were significantly associated with genetic ancestry. Additionally, three of the candidate genes show no effects on pairwise landmark distances while four show distinct patterns of association. For example, FGFR2 is associated primarily with the length of the face. These results represent the first identification of the first genes affecting normal variation in facial features.

Ethnicity-Confirmed Genetic Structure in New Hampshire.

Genetic population structure is known to result from shared ancestry. Though there have been several studies of genetic structure within and among different geographic regions and ethnic groups, little is known of the genetic structure of highly admixed US populations or whether the structure is concordant with self-reported ancestry. In this study, 1529 single nucleotide polymorphisms (SNPs) from 864 healthy control individuals from New Hampshire were measured as part of a bladder cancer epidemiology study. The SNPs were from approximately 500 cancer susceptibility genes scattered throughout the genome. Of these, 960 Tag SNPs were used to cluster individuals using the Structure algorithm for between 2 and 5 subpopulations. Subtle genetic structure was found, suggesting the appropriate number of subpopulations to be either 4 or 5 (FSTs 4 populations: 0.0377, 0.0399, 0.0363, 0.0340; 5 populations: 0.0452, 0.0536, 0.0585, 0.0534, 0.0521). We coded the individuals self-reported ancestries in a genotype fashion (i.e. 0= not reporting that ancestry, 1= reporting part that ancestry, 2= reporting only that ancestry) and conducted a Spearmans rank correlation between each ancestry and the structure q value, which represents the proportion of an individual that originated from a certain genetic subpopulation. Those of Russian, Polish and Lithuanian ancestry most consistently clustered together. The ancestry results support either 4 or 5 subpopulations. In order to investigate linkage disequilibrium (LD), the complete set of SNPs from the 7 most densely genotyped genes were used to make haploview plots between the different groups. The results vary by gene, though for one gene in particular, GHR, the results are very different for 4 subpopulations. These results suggest that despite New Hampshires admixture and presumed homogeneity, there are 4 or 5 distinct genetic subgroups within the population that can be linked to self-reported ancestry and display differences in patterns of LD.

Inference of human demographic parameters using haplotype patterns from genome-wide SNP data.

Accurate inference of human demographic history from genetic data is essential for identification of single nucleotide polymorphism (SNP) association with disease and for inference of natural selection. Haplotype diversity and haplotype sharing carry additional demographic information to that obtainable from SNP frequency spectra, and so we propose a novel method using haplotype summary statistics to fit demographic models to genome-wide SNP data. We divide the genome into 0.25 cM windows and for each we tabulate the number of distinct haplotypes and the frequency of the most common haplotype. We summarize the data by the genome-wide joint distribution of these two statistics. Coalescent simulations are then used to evaluate whether different demographic models are compatible with the observed data. Application of our method to simulated data shows that our method can reliably infer parameters from complex demographic models (such as bottlenecks) and is relatively robust to the levels of SNP ascertainment bias found in many genome-wide datasets. We have applied our method to data collected by the International HapMap Consortium and find that a bottleneck model best fits the CEU population. We have also analyzed a large dataset consisting of Affymetrix 500k data from ~2,900 individuals with ancestry from Taiwan, Japan, India, Mexico and many European countries. Since this dataset includes ~2,300 European individuals, we are able to study haplotype patterns at a fine scale within Europe. Interestingly, we find that within Europe there is a south-to-north gradient with decreasing levels of haplotype diversity moving north, consistent with south to north migrations. We also find that the southwestern European sample has higher haplotype diversity than the southeastern European sample. Additionally, a higher proportion of haplotypes are shared between the southwestern European sample and the Yoruba sample than between southeastern European sample and the Yoruba sample. These two patterns are consistent with recent admixture across the Mediterranean from Northern Africa.

Genome wide analysis and heritability estimation of intelligence in the International Multi-centre ADHD Genetics (IMAGE) study.

Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity and impulsivity. There is growing evidence of heterogeneity in its etiology, pathophysiology and clinical expression. One approach to resolving heterogeneity involves the identification of endophenotypes, intervening variables that might mediate pathways between specific genes and clinical phenotype. IQ is a candidate endophenotype for ADHD. Genome-wide linkage analyses of full scale IQ and IQ subscales were performed in the International Multi-centre ADHD Genetics (IMAGE) study including 1094 families with 1094 DSM-IV combined type ADHD probands and their 1441 siblings (unselected for ADHD status). IQ was measured using five subscales of the WISC-IIIR scale. The full scale prorated IQ score and the five subscales were used as quantitative traits for linkage analysis. 5,407 autosomal SNPs were used to run multipoint regression-based linkage analyses using MERLIN. The h2 estimates from the IQ subscales and the full IQ score ranged from 31% to 100%. Three suggestive linkage signals were found (LOD scores 2, p values 0.001) on chromosomes 7, 9 and 14 for three different subscales. Previously, two regions on chromosomes 7 and 14 were reported as being associated or linked to IQ. Our results, though only suggestive, suggest the presence of additional genetic variants contributing to the variance of IQ in ADHD.

ISBA3 abstracts

Many abstracts from the International Symposium on Biomolecular Archaeology.

Various DNA / Technology

Human ancient DNA analysis within The Genographic Project: a project update and preliminary results from two powerful multiplex SBE typing methods

Wolfgang Haak1, Juan J Sanchez2, Clio Der Sarkissian1, Christina Adler1 & Alan Cooper1

1 The Australian Centre of Ancient DNA, School of Earth & Environmental Sciences, The University of Adelaide, North Terrace Campus, SA-5005 Adelaide, Australia
2 National Institute of Toxicology and Forensic Science, Canary Islands Delegation, 38320 Tenerife, Spain.

The Australian Centre of Ancient DNA (ACAD) is one of 11 Regional Centres of The Genographic Project (TGP), and the only centre dedicated solely to ancient human DNA analyses. Our aim is to provide a temporal perspective to the movements and presence of prehistoric and historic populations through ancient DNA, and establish a time depth to the detailed genetic landscape being generated from the largescale modern human population data of TGP. We will present an update on the current activities and an overview of the protocols and strategies used in the ACAD. The retrieval of authentic human ancient DNA is plagued by methodological problems, and to deal with these we are relying on state-of-the-art methods ranging from sample collection through to data generation. We are using SPEX and multiplex PCR assays followed by SBE typing to analyse both mtDNA coding region markers and nuclear NRY markers. New multiplex assays were designed to amplify highly degraded DNA with an average amplicon length of 60-80bp, targeting 22 mtDNA SNPs and 25 NRY SNPs - to match the core marker panel used within TGP. Preliminary results show that the SBE typing protocols are robust and prove to be highly efficient in targeting minute amounts of suriving aDNA. In addition, the main advantage of SBE has proven to be the detecting power of omnipresent (background) contamination. We conclude that the mtDNA and NRY SBE assays, in combination with sequence data from the mtDNA control region (backed up by cloning and SPEX), and specialised sample collecting systems, provide a powerful means to effectively generate largescale (pre-)historic population data from ancient human samples.

What colour was Attila the Hun’s horse?: genetic signatures of phenotypic traits in archaeological materials

Mim A. Bower¹, Michael G. Campana², Diane Lister¹, Mark Whitten³, Kathy M. Dominy⁴, Angela M. Murphy⁵, Paula Jenkins⁶, Richard Sabin⁶, Michael Akam⁷, Robert Asher⁷ & Matthew Binns⁵.

¹ McDonald Institute for Archaeological Research, University of Cambridge, Downing Street, Cambridge, CB2 3ER, UK.

² Department of Archaeology, University of Cambridge, Downing Street, Cambridge, CB2 3DZ, UK.

³ Comparative Population Linguistics Group, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.

⁴Department of Medical and Molecular Genetics, King's College London School of Medicine, Guy's Hospital, London, SE1 9RT, UK.

⁵Department of Veterinary Basic Sciences, the Royal Veterinary College, Royal College Street, London, NW1 0TU, UK.

⁶ Department of Zoology, Natural History Museum, Cromwell Road, South Kensington, London SW7 5BD, UK

⁷Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.

Studying the phenotype, i.e. what a plant or animal looked or behaved like, is perhaps the next “Holy Grail” in ancient DNA research. If we could trace the genes responsible for particular characters in archaeological specimens, it would open the door to some highly relevant and interesting questions in archaeology; the least of which may be the elusive “domestication gene”, but could cover more basic questions, such as: did people in mediaeval Europe prefer cows that had a tendency to lay down fat or muscle? When and where did a particular genetic disorder enter a domestic population? Was the spread of agriculture influenced by adverse environmental conditions? Or what colour was Attila the Hun’s horse? We could begin to understand past approaches to animal and plant husbandry, the expression of past human choice and selection, and past understanding of biological processes such as heredity. Fortunately, molecular biology is fast uncovering the genes responsible for particular phenotypic traits – the only problem, and a significant one perhaps, is looking for these genetic signatures in ancient DNA, known to be a recalcitrant material for analysis.

Here we present the results of our research on phenotypic loci in various historic and archaeological materials (bones, teeth, parchment, hide, seeds), and discuss the potential for future of phenotypic research in archaeogenetics.

Greece & Italy

Aristophanes and Stable Isotopes: Comparing literary and isotopic evidence of diet in Classical Thebes, Greece.

Efrossini Vika ^1,2, Mike Richards^3,4, Holger Schutkowski² and Vassilis Aravantinos⁵

¹ School of Conservation Sciences, Bournemouth University, BH12 5BB, UK

² Division of Archaeological, Geographical and Environmental Sciences, University of Bradford, BD7 1DP, UK

³ Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, DE

⁴ Department of Archaeology, Durham University, DH1 3LE, UK

⁵ IX Ephorate of Prehistoric and Classical Antiquities, Thebes 60200, GR

The greatest advantage for an archaeologist working with historically dated material is the existence of literary sources, which can complement scientific analyses in archaeology. The present study compiles a dietary profile for the inhabitants of Classical Thebes, using δ¹³C and δ¹⁵N isotope analysis, comparing this evidence with information on diet as presented in Aristophanes’ comedies (Acharnians, Plutus, Wasps).

Aristophanes’ work is abundant in satirical scenes, which emphasize personal attributes and local characteristics. Within this realm, it is possible to extract information on dietary habits, trade and economy in the Classical times. Merchants from Thebes oftentimes appear in his work, reflecting the city’s wealth. Among the goods deriving from this region, eels feature prominently, and are praised as an exceptional delicacy.

Stable isotope analyses of bone collagen were carried out for individuals from the Classical burials of the Northeastern cemetery of Thebes. Results show a remarkable increase of the nitrogen values relative to the previous periods, which is not accompanied by an analogous enrichment of the carbon values. This profile can partly be explained by an increased consumption of freshwater sources in Thebes during the Classical times, such as Aristophanes’ famous eels.

The results demonstrate how the integration of isotopic and literary evidence can provide novel information about Classical society in Thebes.

Greek myths

Terry Brown
Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, M1 7DN, UK

The Greek Bronze Age is the time of the Homeric legends and the Greek myths. The work of Schliemann, Tsountas, Wace and others revealed the material remains of the Mycenaean civilisation that was dominant in the Aegean during the 17th to 12th centuries BC, these remains including human skeletons, some buried with rich grave goods. Biomolecular archaeologists have been attracted to the Greek Bronze Age because there are interesting kinship questions for the burials at several sites, and because aDNA could throw light on the impact of diseases such as malaria on these societies. Addressing these questions clearly requires that aDNA is preserved in the relevant material, and our conclusion after ten years of work is that largely it is not. We have found no indication of aDNA at Lerna, Antron Grave Circles A and B and Mycenae Grave Circle A. At Mycenae Grave Circle B, we detected mitochondrial aDNA in just four of the 22 skeletons that we studied. Only at Kouphovouno have we have obtained sufficient aDNA results to attempt any kind of archaeologically relevant study. The distinguishing feature of Kouphovouno is that we obtained skeletal samples immediately after their excavation. We used optimised PCR systems in order to maximise our chances of detecting aDNA if it was present, but we also used a high containment facility and took scrupulous care to remove surface contamination from the bone samples and to prevent cross-contamination with PCR products from previous experiments. We also confirmed that our negative results were not due to inhibition of PCRs by substances co-purifying with aDNA. Negative results tend not to get widely publicised – we would have preferred positive ones but not if they lead to new Greek myths.

Late Bronze Age Diet in the Greek Peloponnese

E.I.Petroutsa1 & M.P.Richards2

1.20 Koundouriotou str., Exarcheia, 10683 Athens, Greece

2.Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany


In this paper we present the results of an isotopic study of bone collagen samples from four Late Bronze Age cemeteries from the Northern Peloponnese in Greece: Voudeni, Aghia Triada, Almyri and Kritika. Through isotope analyses we sought to characterise the general diets in these four sites, especially the amounts of marine protein, as well as animal vs. plant proteins in diets. We also compared the isotopic results from these sites with other Bronze Age sites, including Mycenae. Despite the coastal location of most of the sites we could not find evidence of any significant consumption of marine foods. Instead, most human diets are based on a mixture of plant and animal protein, from C3 terrestrial resources.

Preliminary results of C and N isotope analyses and 14C dating of prehistoric humans and animals from the Mesolithic-Neolithic site of Grotta dell’Uzzo, Sicily, Italy

Marcello A. Mannino1, Sahra Talamo1, Rosaria Di Salvo2, Vittoria Schimmenti2, Marcello Piperno3, Sebastiano Tusa4, Antonio Tagliacozzo5, Michael P. Richards1,6

(1) Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig (Germany)

(2) Museo Archeologico Regionale ‘Antonino Salinas’, Via Bara all’Olivella 24, 90133 Palermo (Italy)

(3) Dipartimento di Scienze Storiche, Archeologiche ed Antropologiche dell’Antichità, Sezione di Paletnologia, Università di Roma ‘La Sapienza’, Via Palestro 63, 00185 Roma (Italy)

(4) Soprintendenza del Mare, Palazzetto Mirto, Via Lungarini 9, 90133 Palermo (Italy)

(5) Museo Nazionale Preistorico Etnografico ‘L. Pigorini’, Piazzale Guglielmo Marconi 14, 00144 Roma E.U.R. (Italy)

(6) Department of Archaeology, University of Durham, South Road, DH1 3LE Durham (United Kingdom)

Grotta dell’Uzzo is one of the key sites in the Mediterranean for the study of the changes in subsistence that took place in the transition from hunter-gatherer (Mesolithic) to agro-pastoral (Neolithic) economies. The cave is also important because 13 Mesolithic humans have been unearthed from 11 burials excavated within it. In order to study the diets of these humans, C and N isotope analyses were undertaken on skeletal remains recovered in the burials and from different trenches excavated at the cave. The preliminary results of these analyses suggest that the main sources of dietary protein were terrestrial and probably originated from the consumption of mammalian herbivores such as red deer (the most commonly exploited animal for much of the cave’s occupation). The contribution of marine resources to human diet at Grotta dell’Uzzo was probably not very significant in absolute terms. This finding might appear to be in contrast with the results of the archaeozoological studies, which have demonstrated that there was an intensification in shellfish collecting and in fishing from the end of the Mesolithic to the inception of the Neolithic. However, given that on the basis of the chronological data currently available the burials predate the end of the Mesolithic, the results of the isotope analyses are in line with the findings of the archaeozoological studies and of the seasonality studies, which have shown that marine resources (mainly represented by shellfish) were not exploited throughout the year before the final stages of the Mesolithic.

Plants

Phylogeographic analysis of barley (Hordeum vulgare) landraces shows that the distribution of lineages retains an imprint from the initial patterns of agricultural spread through Europe.

Huw Jones1, James Cockram1, Lydia M Smith1, Ian MacKay1, Robin G Allaby2, Terrence A Brown3, Wayne Powell1

1 National Institute of Agricultural Botany, Huntingdon Road, Cambridge, CB3 0LE

2 Warwick HRI , Wellesbourne, Warwick , CV35 9EF

3 Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, 131 Princess Street, Manchester, M1 7DN

In the 8000 years since barley was first introduced into the continent of Europe, the evolution of this crop species has been subject to selection under biotic and abiotic pressures. European farmers will have influenced the distribution of barley ecotypes by the movements of early farmers and by their selection of preferred types. The evolution of barley in Europe will also reflect the differing environments in which it has been grown. Modern barley cultivars from across Europe can be seen to differ in their morphology and growth habits. We have attempted to dissect the origins of these different forms by examining the landraces and assess the relative importance of human and environmental selection on modern barley lineages.

We have sampled barley landraces from Europe and discovered their population structure by microsatellite genotyping and statistical analysis. We have used passport data from germplasm collections to characterise the 2-row / 6-row head morphology, hulled / naked grain morphology and the spring / winter growth habit of these sub-populations. The genetic variation underlying key adaptive traits controlling flowering time has been explored by re-sequencing the photoperiod response gene Ppd-H1 and by haplotype analysis at the spring / winter vernalisation genes Vrn-H1 and Vrn-H2. These studies were designed to run alongside analysis of ancient DNA and historic DNA from barley and emmer wheat collected from across Europe.
The population structure we have discovered divides barley landraces into a number of sub-populations each with a distinct geographic distribution. Our genetic data for key adaptive traits allows us to understand the environmental influence on the geographic distribution of each lineage. Where lineages with a similar adaptive profile have distinct geographic distributions we see the imprint of early dispersal by ancient farmers.

Stable isotope evidence for the consumption of millet in Bronze Age Italy

Mary Anne Tafuri1, Oliver Craig2 & Alessandro Canci2
1 Dipartimento di Biologia Animale e dell’Uomo, Sapienza Università di Roma, P.le A. Moro, 5, 00185 Roma. Italy – email: maryanne.tafuri@uniroma1.it

2 Department of Archaeology, University of York, BioArch Biology, S Block PO Box 373 York YO10 5YW, UK

3 Dipartimento di Storia e Tutela dei Beni Culturali, Università degli Studi di Udine, Via Palladio, 8, 33100 Udine. Italy


This study presents, via carbon and nitrogen stable isotope analysis on human and animal bone collagen, new data on diet and subsistence strategies at northern and southern Italy Early and Middle Bronze Age sites, which clearly indicate the direct or indirect consumption of C4 plants. On the basis of paleobotanic data available and as suggested by previous similar studies, we argue here that the isotopic signal obtained can be associated with the consumption of millet (P. miliaceum and Setaria italica). If such an interpretation were true, while we wait for further paleobotanical and isotopic studies, we should consider the results obtained as the earliest evidence of millet consumption in prehistoric Europe. We thus suggest a possible pattern of distribution in the Peninsula of the practice of production and consumption of millet, while setting a new agenda on food security and subsistence strategies in prehistoric Italy

Cattle & Goats

A PCR system free of contaminating DNA for the amplification of bovine DNA from bovine fossils

Camille Berthelot, Sophie Champlot, Marie Liouville, Thierry Grange, Eva-Maria Geigl

Institut Jacques Monod CNRS UMR 7592, Universités Paris 6 et 7, Tour 43, 2, Place Jussieu, 75251 Paris cedex 05, France

Palaeogenetic analyses of bovine bone remains from many Neolithic sites in Europe and in Southwest Asia suffer from poor DNA preservation in these bones that increases the risk of amplification of contaminating modern bovine DNA. Indeed, trace amounts of contaminating bovine DNA occur ubiquitously. In particular, they can be found at low quantities in biochemical reagents used to extract and amplify DNA. These contaminating molecules mimic ancient DNA molecules. Indeed, the contamination rate often resembles the success rate of ancient DNA studies from bovine remains and the length of the contaminating DNA fragments is often comparable to ancient DNA fragments. We elaborated a decontamination protocol for PCR reagents combining various treatments to reduce contamination towards zero. This system significantly increases the reliability of ancient DNA results from bone remains of domesticated animals.

Detecting selection in ancient cattle remains: Pre industrial selection in Bos Taurus and SNP typing in medieval cattle remains

Emma Svensson1, Anders Götherström1

1 Evolutionary Biology, Evolution Genomics & Systematics, Uppsala University, 752 36 Uppsala, Sweden

Historic and prehistoric animal breeding is an enigmatic topic, complicated to approach with conventional genetics and osteology. Questions like when it started, and how strict it was, are of general interest, but it is also complicated to generate a suitable dataset for such questions. By tracing changes in genetic diversity with serial data we can find out how cattle has changed since the domestication of the aurochs to become the array of breeds seen today. Cattle are likely to have been subjected to selection predating the 18th century but the information is scarce. Using a 12plex SNP stream system alongside pyrosequencing we typed up to eight coding and six neutral SNPs in 142 ancient and 216 modern Bos Taurus from Northern Europe. We found a significant decrease in total heterozygosity over time for the coding SNPs which are presumably associated with phenotypic traits such as milk quality and coat colour while neutral markers on the other hand don’t show any significant change over time. This suggests that the decline in diversity is caused by artificial selection and not other genetic processes. The medieval period was a dynamic time in northern European history. The society was moving toward a higher degree of specialization in general, and a number of towns based on trade arouse in Scandinavia. Our findings of early selection fit well with the more sophisticated farming and higher degree of animal breeding that likely occurred at this time.

Using new and old approaches to study bovid systematics and evolution across Eurasia

Alan Cooper¹, Kefei Chen¹, Beth Shapiro²

¹ The Australian Centre of Ancient DNA, School of Earth & Environmental Sciences, The University of Adelaide, North Terrace Campus, SA-5005 Adelaide, Australia

² Department of Biology, The Pennsylvania State University, 326 Mueller Laboratory, University Park PA 16802, USA

Ancient DNA studies of bovid remains from Europe have detected four main taxa: Bison bonasus (the European Bison); Bison priscus (Steppe bison), Bos primigenius (Aurochs); and early Bos taurus (Daisy). Studies of bones recovered from caves in the Urals and Caucasus, and from material dredged from the North Sea, have revealed a fifth European bovid – the Caucasus bison. Previously recognised only as a sub-species of European bison, this taxon appears to represent a separate species, with more genetic diversity than Beringian populations of Bison priscus, suggesting a long evolutionary history and stable population size. It has changed ecological dominance with Bison priscus at several points in the Pleistocene, which appear to be related to climatic and environmental change.

We have been using emulsion PCR and high-throughput hybridisation-based SNP screening systems that can simultaneously analyse 50,000 bovid SNPs to explore the genomic evolution of ancient bovids during the Pleistocene and subsequent domestication. We have been concentrating on pre-domestic Bos taurus specimens, as well as representatives of the other Pleistocene bovid species. This approach holds enormous promise for fine-scale temporal analyses of evolution in response to climate and environmental change, as well as archaeology and domestication.

The process of cattle domestication during the Neolithic as revealed by a large-scale palaeogenetic study

Eva-Maria Geigl, Mélanie Pruvost, Marie Liouville, Camille Berthelot, Reinhard Schwarz, Sophie Champlot, Thierry Grange, Virginia Bessa-Correia, Hans-Peter Uerpmann, Lamys Hachem, Hitomi Hongo, Séverine Braguier

Institut Jacques Monod CNRS UMR 7592, Universités Paris 6 et 7, Tour 43, 2, Place Jussieu, 75251 Paris cedex 05, France

Several disciplines can contribute to the elucidation of the processes of animal domestication during the Neolithic, such as archaeology, archaeozoology, and, more recently, isotope and genetic studies. The processes of domestication leave genetic signatures in the genomes of the domesticated animals that can be explored via the combination of both genetic analyses of extant domesticates and palaeogenetic analyses of bone remains of the first generations of domesticated animals and of their wild ancestors. We adopted this approach to shed light on the domestication of the aurochs. We studied roughly 250 Bos bone remains from Southwest Asia, according to archaeological and archaeozoological evidence the presumed centre of cattle domestication, and from France, the region where the two Neolithic migration currents mingled. To obtain authentic palaeogenetic results, several methodological difficulties related to poor DNA preservation and reagent contamination had to be solved. We will present both the methodological challenge that we encountered and overcame and the results of our large-scale study.

Cattle domestication and the troublesome aurochs

Cecilia Anderung1, Jurgita Baubliene2, Daniel Makowiecki3, José Miguel Carratero4, Linas Daugnora2, Juan Luis Arsuaga5 and Anders Götherström6

1Palaeontology Department, Natural History Museum, Cromwell road, London SW7 5BD, Great Britain.
2Department of Anatomy and Histology, Lithuanian Veterinary Academy, Tilžes str. 18, LT-3022, Kaunas, Lithuania
3Institute of Archaeology, Nicolaus Copernicus University, Podmurna 9/11 87-100 Toruń, Poland
4Laboratorio de Evolución Humana, Departamento Ciencias Históricas y Geografía Edificio I+D+I Plaza de Misael Bañuelos s/n, 09001, Burgos, Spain
5Centro Mixto UCM-ISCIII de Evolución y Comportamiento Humanos c/ Sinesio Delgado Nº 4 Pabellón 14, 28029 Madrid, Spain
6Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, 75236 Uppsala, Sweden

A number of genetic studies relating to the origin of modern cattle have been published recently. In particular the extinct European aurochs (Bos primigenius), progenitor of the modern domesticated form, has attracted a lot of attention. European aurochs bones that have yielded mitochondrial DNA are genetically clearly different from modern cattle. This genetic data, in combination with the genetic patterns observed in modern cattle, has led to the suggestion that modern cattle have a single origin in the Near East, and that the European aurochs population had little to do with their domestication.

However, we ask the question: could this picture of European cattle domestication be too simple?

Here we present results from an investigation of published and novel aurochs sequences from Lithuania, Spain, Poland, and Britain, giving special attention to the Spanish sequences. We looked at the mitochondrial DNA variation in Iberian aurochs remains and searched for aurochs sequences in a domestic context. We find that cattle and aurochs mitochondrial sequences from Iberia deviate from the pattern observed in sequences from Central and Eastern Europe.

In the light of this data, we discuss the possibility of local aurochs domestication events in Europe.

High mtDNA diversity among cattle and goats from the earliest Neolithic settlements on the European continent

Amelie Scheu1,2, Norbert Benecke2 and Joachim Burger1
1 AG Palaeogenetik, Institut für Anthropologie, Johannes Gutenberg-Universität, 55099 Mainz, Germany

2 Deutsches Archäologisches Institut, Eurasienabteilung, 14195 Berlin, Germany

The process of domestication includes a decline in genetic variability. Additional homogenisation occurs due to subsequent colonisation events, such as the Neolithisation of Europe. Our previous studies have shown genetic uniformity even among early Neolithic European cattle (Bollongino et al. 2006). But modern goats also share more than 90% of the same mtDNA haplogroup.

To find out exactly when and where this genetic bottleneck arose during the Neolithisation of Central Europe, we investigated remains of early domesticates on the border between Asia and Europe, i.e. at the origin of the trans-Danubian route of Neolithisation. That region, particularly the area around the Bosphorus and the transit country of Bulgaria, plays a crucial role.

We found higher mtDNA diversity among Neolithic and Bronze Age domesticated cattle East and West of the Black Sea (haplogroups T, T2 and T3) than in Central European populations. Among goats, we found the two different mtDNA haplogroups A and G. G had previously been found among modern goats only near the Fertile Crescent (Naderi et al. 2007).

Our results argue for large and genetically more diverse herds imported to this area and/or for intense trade. Furthermore, they indicate that a second wave of expansion in the direction of Central Europe is responsible for the final loss of mtDNA diversity.

Ice man Schnidi’s trousers: insight into prehistoric goat diversity

Angela Schlumbaum1, Serge Volken 2, Marquita Volken 3, Jörg Schibler4, Peter Suter 5 Kathrin Glauser6 & Albert Hafner 7

1 Institute of Prehistory and Archaeological Science, University of Basel, Spalenring 145, 4055 Basel, Switzerland

2 Gentle Craft, Rue du Rôtillion, 10, 1001 Lausanne, Switzerland

3 Gentle Craft, Rue du Rôtillion, 10, 1001 Lausanne, Switzerland

4 Institute of Prehistory and Archaeological Science, University of Basel, Spalenring 145, 4055 Basel, Switzerland

5 Archaeological Service of the Canton Bern, Brünnenstrasse 66, 3001 Bern, Switzerland

6 Archaeological Service of the Canton Bern, Brünnenstrasse 66, 3001 Bern, Switzerland

7 Archaeological Service of the Canton Bern, Brünnenstrasse 66, 3001 Bern, Switzerland
Since 2003 more than 300 prehistoric remains were discovered in the vicinity of a melting ice patch of the Schnidejoch (2750 m; Bernese Alps, Switzerland), paralleling the finds accompanying the Iceman from the Tisenjoch (Oetztal Alps, Italy/Austria; “Oetzi”). One leg of a Neolithic leather trouser was found and 14C dated to 2900 – 2600 BC. The morphological identification of the animal skin was ambiguous because of the bad preservation of diagnostic features. Based on grain patterns of the skin the leather was made either from sheep or goat.

Because of the importance of the object, a genetic identification of the animal species was attempted. After DNA extraction with QiAmp DNA Mini Kit a 70bp fragment of the mitochondrial cytochrome b gene was amplified in the diluted extract. The leather was made of goat skin (Capra hircus). Six geographically broadly distributed goat lineages are recognized based on mitochondrial d-loop variation, of these lineage A and C were identified by others in prehistoric goat bones from France. The “trouser’s goat” however, belongs to lineage B, which is common in Asia, but extremely rare in Europe today.

An Ancient DNA study from The Farm Beneath the Sand

Martin Bay Hebsgaard1

1 Dept. of Biology, University of Copenhagen, Universitetsparken 15, Denmark
Applying ancient DNA techniques on samples from the archaeological site “The Farm Beneath the Sand” (GUS) near Nuuk in Southwest Greenland is the first attempt to extract DNA from these relative young but novel samples. The sample site highlight the dramatic landscape changes that resulted in floodplain aggradations that eventual buried the site fixing the site under perma-frozen conditions.
The Farm beneath the Sand is situated on a plain surrounded by low mountains ca. 80 km east of Nuuk. When the building remains were found they were overlain by ca. 1,5 m thick layers of sand and gravel, and today the plain in front of the farmhouse appears as a sandy dessert intersected by meandering watercourses that are draining off the icecap.

All together the samples yielded DNA from humans, cattle, sheep, goat and reindeer. Quantification shows approximately 16 times more DNA from cattle than from sheep. Goat DNA was undetectable using Quantitative PCR. The amount of cattle DNA declines over time while sheep DNA probably reflects background variation.
Thanks to thick layers of sand and gravel that may have protected the DNA in the anthropogenic layers ancient DNA is usable in an archaeological context in the reconstruction of the past. In this example ancient DNA research has helped to refine and define archaeological interpretations of the Norse life by adding information not seen by the naked eye. In the future ancient DNA have the capacity to be used more vigorously to investigate the diet of the Norse and show what function specific farms may have had during the settlement. As in this study the future research is not limited to animal DNA but DNA from plant and humans can be used to address different questions.

Horses

Pleistocene Horses genetics before and after the last glacial maximum

Sebastian Lippold¹ and Michael Hofreiter¹

¹ Dept. Evolutionary Genetics, MPI for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany

We are investigating how the last glacial period affected the genetic composition of populations, particularly the horse (Equus spec.). Vast climatic changes that occurred between 30,000 and 12,000 years BP resulted in dynamic mammalian population structures. Restriction and expansion events during this period influenced both the genetic distribution and variability of a variety of mammals. We focus on western European horse populations, and try to characterize their genetic diversity and phylogeographic patterns both before and after the last glacial maximum. We sequence 600 bp of mtDNA from the mitochondrial D-Loop of different individuals obtained from different locations. Our initial results indicate tremendous genetic diversity, but no phylogeographic pattern within this marker. The genetic distribution of these ancient samples also falls within the broad diversity range apparent in recent horses. Because of this finding, we started screening the DNA samples for additional nuclear markers. Our comparison of these different markers has enabled us to reconstruct several scenarios for horse population dynamics during this period.

Investigating Eneolithic horse exploitation in northern Kazakhstan, via compound-specific stable carbon and deuterium isotope analysis of pottery.

Natalie A. Stear1, David Chivall1, Alan K. Outram2 and Richard P. Evershed1 1Organic Geochemistry Unit, School of Chemistry, University of Bristol, Clifton, BS8 1TS, UK 2 Department of Archaeology, SoGAER, University of Exeter,Laver Building, North Park Road, Exeter, EX4 4QE, UK The Eneolithic site of Botai in northern Kazakhstan has been the centre of much debate regarding its role in early horse domestication (Levine, 1999; Olsen, 2003). The faunal assemblage from this remarkable site was almost entirely comprised of horse (99%); however it has remained unknown whether any of these horses were domesticated. Horse domestication is extremely difficult to detect morphologically from skeletal remains and consequently it is necessary to establish a reliable proxy for detecting ancient domestic horse populations. Fermented mare’s milk (Kumyss) is commonly consumed in rural communities in Kazakhstan, a tradition dating back to prehistory. It is not clear if the milking of horses began (i) in the Eneolithic, during the height of the horse centred communities of the Botai culture; (ii) in the Bronze Age, in response to the milking of ruminants or, (iii) much later. If mare’s milk were identified in ancient pottery it would serve as conclusive evidence for the presence of domestic horses and enable a chronology of horse exploitation to be established. Equine fat residues can be identified in potsherds using compound-specific stable carbon isotope analysis, but unlike ruminant fats, equine milk and adipose fats are indistinguishable from one another based on δ13C values. However, we show that it is possible to further classify equine fats as either milk or adipose, based upon the δD values of their C16:0 and C18:0 fatty acids which are determined using GC-thermal conversion-IRMS (GC-TC-IRMS). This new proxy has been applied to organic residues extracted from potsherds from Botai as part of a large scale investigation of Eneolithic and Bronze Age pottery from sites in northern Kazakhstan. Using the δ13C and δD values obtained from the Botai residues we have been able to detect equine milk residues preserved within the pottery and consequently, we provide the first direct evidence for the presence of domestic horses at Botai during the Eneolithic.

Anatolia

Detecting dairying with stable calcium isotope ratios (δ44/42Ca) of bones and teeth

Linda M. Reynard^1,2, Robert E.M. Hedges¹ & Gideon M. Henderson²

¹ Research Laboratory for Archaeology and the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford, OX1 3QY, United Kingdom

² Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, United Kingdom

The use of dairy products in antiquity is an important part of the development of agriculture and pastoralism in Eurasia. They offer advantages of more efficient land use, improved nutrition, and more reliable and constant access to protein. Understanding the adoption of dairy, its timing, and geographical spread is relevant to developing a fuller understanding of changes in subsistence from the Neolithic.

Detecting and quantifying dairy product consumption in antiquity has, to date, relied on indirect evidence such as the age and sex structure of faunal remains and potsherd lipid residues.. To complement these methods, we have measured stable calcium isotope ratios (δ^44/42Ca) of bones and teeth which allows the direct detection of dairy consumption by prehistoric humans. Dairy products have lower δ^44/42Ca than other dietary calcium inputs, and this results in lower δ^44/42Ca of the dairy consumer. We have measured the δ^44/42Ca of human and animal bones from a range of archaeological sites by MC-ICP-MS. Results from the Mesolithic to the Neolithic at the key Near Eastern site of Abu Hureyra, Syria (11,100 –7,300 BP) show a δ^44/42Ca signal attributable to dairy consumption by ancient humans, with a changing pattern through time. Work on intra- and inter-tooth δ^44/42Ca variability is in progress as this material is expected to form a robust archive of in vivo isotope ratios.


Britain

An investigation into origins of individuals from a mass grave in Roman Gloucester, UK: strontium and stable isotope evidence

Carolyn Chenery^1,2, Gundula Müldner¹, Jane Evans², Louise Loe³, Nicholas Márquez Grant³, Hella Eckardt¹ Stephanie Leach¹, Mary Lewis¹

¹ Department of Archaeology, University of Reading, Reading, Berkshire.

² NERC Isotope Geoscience Laboratory, British Geological Survey, Keyworth, Nottingham.

³ Oxford Archaeological Unit Ltd, Janus House, Osney Mead, Oxford.

Contrary to popular assumptions, Britain under Rome was truly multi-cultural, with historical and epigraphic evidence recording the voluntary and forced migration of Gaulish, Germanic and North African individuals into the British provinces refs. This paper presents the results an isotopic investigation of population diversity in 1^st to the 4^th century Roman Gloucester; focusing on individuals found in a late 2^nd century mass burial pit and comparing them to those found in single graves.

The results suggest that the majority of the individuals buried in the London Road Cemetery were from areas within the UK. However, the isotope data has identified a number of individuals whose origins lay in a region with a warmer climate than the UK. Whether these were soldiers, their followers or merchants cannot be determined.

On Rome’s Northern Frontier: Multi-isotopic investigations into cultural diversity in Roman York

Gundula Müldner1, Carolyn Chenery1,2, Stephany Leach1, Mary Lewis1 & Hella Eckardt1

1 Department of Archaeology, University of Reading, Whiteknights, PO Box 227, Reading RG6 6AB, England

2 NERC Isotope Geoscience Laboratory, British Geological Survey, Keyworth, Nottingham, NG12 5GG, England

Britain under Rome was a multi-cultural society, with historical and epigraphic evidence attesting to the presence of migrants from continental Europe, North Africa and the Middle East. Here, we combine isotope analysis for the reconstruction of diet (C,N) and mobility (Sr, O) with skeletal (craniomorphometric) and archaeological data, in order to investigate diversity in Roman York, the political, military and administrative centre of the North. The results show a heterogenous population and highlight the varied life-histories of individuals in the northernmost provincial capital of the Empire; however, they also show that skeletal and isotopic evidence are not always easily correlated. It is suggested that a diet high in marine protein was used to demonstrate a “Roman” identity.

Investigating Marine Food Consumption in Prehistoric Humans via the δ13C values of Collagen Amino Acids

Philip Dunn1, Richard P. Evershed1 & C. Joshua Pollard2
1 School of Chemistry, University of Bristol, Organic Geochemistry Unit, School of Chemistry, Cantock's Close, Bristol, BS8 1TS, UK

2 Department of Archaeology and Anthropology, 43 Woodland Road, Clifton, Bristol BS8 1UU, UK

The current debate concerning the importance of marine foods in the diets of prehistoric peoples has stimulated interest in refining analytical approaches based on stable isotopes. An alternative to the widely bulk collagen approach is to investigate the stable carbon isotope composition of human bone collagen at the amino acid level. Our investigations of prehistoric humans from the Western Cape, South Africa, have shown that the Δ13CGlycine-Phenylalanine values for bone collagen amino acids correlate strongly with bulk δ15N values and provide a new proxy for marine food consumption. We are currently applying this new approach to human skeletal remains from northern Europe.
The tomb at Isbister lies on the south west coast of South Ronaldsay and is one of a number of Neolithic cairns found in the Orkney Islands. During excavation in 1976, the stalled main chamber and three side chambers were found to contain some 16,000 human bones and bone fragments deriving from a minimum of 341 individuals along with a wide range of faunal remains. Previous analyses of bone collagen from the human remains have shown that the tomb was in use from 4,500 to 3,800 BP and bulk collagen stable isotope values for 5 individuals lay in the range -19.9 to -21.2 ‰ indicating a predominantly terrestrial diet, which is surprising for people that lived so close to the coast.
We have now employed the recently introduced LC-IRMS technique to determine the δ13C values of bone collagen amino acids from 22 individuals from Isbister. The results will be compared to those obtained by GC/C/IRMS. The derived Δ13CGlycine-Phenylalanine values give enhanced insights into the dietary habits of the people of Isbister.

Northern Europe

Large-scale FLX-sequencing and the Swedish Neolithic

Helena Malmström1,2, Anna Linderholm3, M. Thomas P. Gilbert2, Mikael Brandström1, Jan Storå4, Petra Molnar4, Christian Bendixen5, Gunilla Holmlund6, Kerstin Lidén6, Anders Götherström1, Eske Willerslev2

1Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden

2Ancient DNA and Evolution Group, Biological Institute, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen O, Denmark

3Archeological Research Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden

4Osteoarchaeological Research Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden

5Department of Genetics and Biotechnology, Danish Institute of Agricultural Sciences Research Centre Foulum, K25 PO Box 50, DK-8830 Tjele, Denmark

6National Board of Forensic Medicine, Department of Forensic Genetics and Forensic Toxicology, Artillerigatan 12, SE-587 58 Linköping, Sweden

The relationship between the contemporary hunter-gatherer Pitted Ware Culture (PWC) and the farming Funnel Beaker Culture (TRB) in Middle Neolithic (3300-2500 B.C.) Sweden has been debated for more than a century. We approach this issue by determining the genetic signatures of skeletal remains from both complexes. Initially, we generated large amounts of “cloned” ancient mitochondrial DNA (mtDNA) PCR amplicons using a single run of the Genome Sequencher FLX System, and a recently described primer tagging protocol. Our data set consisted of Hypervariable Region I (HVRI) amplicons derived from bleach pre-treated powdered bone from Neolithic humans as well as from a large number of negative controls (animal samples, extraction and PCR blanks). We compared the ‘clone’ data with sample quality indicators, such as the number of PCR starting template molecules and the degradation ratio of DNA in the sample (number of long/short fragments). The data shows distinct patterns that differ between high and low quality extracts. After establishing the efficacy of the large scale sequencing approach, additional high-quality PWC and TRB samples (based on collagen preservation) were sequenced in a second FLX run. The compiled data yielded unambiguous HVRI sequences for approximately 40 Neolithic human samples, each compiled from cloned, duplicate PCR amplicons derived from overlapping HVRI fragments. F-statistics and AMOVA revealed significant genetic differences between the PWC and TRB samples, indicating that they indeed comprise of two distinct groups.

Allele frequencies of the lactase gene in Scandinavian Neolithic populations, hunter-gatherers vs. farmers

Anna Linderholm1, Helena Malmström2, 5, Love Dalén3, Kerstin Lidén1, Jan Storå4, Petra Molnar4, M. Thomas P. Gilbert5, Eske Willerslev5, Gunilla Holmlund6, Anders Götherström2
1Archeological Research Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden

2Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden

3Marie Curie Fellow, School of Biological Sciences, University of London, United Kingdom

4Osteoarchaeological Research Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden

5Ancient DNA and Evolution Group, Biological Institute, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen O, Denmark

6National Board of Forensic Medicine, Department of Forensic Genetics and Forensic Toxicology,Artillerigatan 12, SE-587 58 Linköping, Sweden

Genetics and culture are believed to interact, but it has been difficult to find direct evidence for the process. One example that has been put forward as a candidate is lactase persistance in adulthood, i.e. the ability to continue drinking milk. This genetic trait is believed to have evolved within a short space of time in connection with the emergence of farming cultures. Here we investigate certain Scandinavian Neolithic populations and their allele status with respect to the gene responsible for lactase persistance. We find that the allele responsible for lactase persistance was common and not significantly different from modern Swedish populations among Neolithic farmers, whereas Neolithic hunter-gatherers had a lower frequency of the allele.

aDNA analysis of human population samples from the Danish past – what have we learned?

L.C. Melchior¹, N. Lynnerup² and J.Dissing¹.

¹Research Laboratory, Institute of Forensic Medicine, University of Copenhagen, Denmark, ²Laboratory of Biological Anthropology, Institute of Forensic Medicine, University of Copenhagen, Denmark.

During an ongoing survey of the Danish genetic past we analyzed mtDNA from teeth from human remains from a range of burial sites from medieval times to the Stone Age. To ensure the highest possible degree of reliability generally accepted authentication criteria (including sequencing of multiple clones and replication by different researchers) as well as additional precautions (e.g. testing of laboratory performance) were observed.

Unequivocal assignment of mtDNA haplotypes was possible for more than 50 ancient subjects; however, the success rate varies substantially between sites. The highest success rate (11 out 11) was obtained with freshly excavated Viking Age subjects (ca AD 1,000), but good results were also obtained for recently excavated Iron Age sites (AD 0-400). Poor results were found with highly manipulated subjects (contamination) and with most of the Stone Age samples (4,500-5,000 YBP).

While laboratory related contamination can effectively be prevented by the abovementioned precautions, the most serious challenge to authenticity is caused by pre-lab contamination. This problem was tackled using several approaches including analysis of DNA damage patterns, haplotyping of archaeologists, phylogenetic testing and as the most efficient measure, sampling from the ancient subjects during exhumation. We show that reliable retrieval and analysis of DNA from ancient humans is indeed a possible undertaking.

A high degree of nucleotide diversity was observed in the ancient populations, and at four out of six locations the diversity was considerable higher than among modern Danes. Also, we observed a consistently higher abundance of Hg I (10-20%) than among modern Danes (~3%).The effect of the Black Death has been suggested as a possible explanation for a similar decline in the English genetic diversity. Interestingly, we found the highest genetic diversity in a 15^th century population sample long after the major outbreak in the14^th century.

NspI typed transition within PRNP gene (A385G / Met129Val) confirms rapid shift in allele frequencies during The Second Millennium

Henryk W. Witas1, Magdalena Kołodziejczak1, Paweł P. Liberski2
1 Dept. of Molecular Biology, Medical University of Lodz, 91-738 Lodz, Sporna 36/50, Poland

2 Dept. of Molecular Pathology and Neuropathology, Medical University of Lodz, 92-216 Łódź, Pomorska 251, Poland

Although precise biological role of prion proteins (PrPC) is still a subject of extensive study and debate, a few suggestions of their involvement in cellular processes have been described, including involvement in biology of synapse, short-term memory formation and long-term memory consolidation. Prion proteins became commonly recognizable as a cause of some human transmissible spongiform encephalopathies (TSE). Among a number of SNPs, A385G / Met129Val is assumed as a factor involved in the pathogenesis of TSEs (e.g. kuru) and a marker of memory efficiency as well. Although frequency of Met129Val alleles are precisely characterised for modern populations and its significance discussed, no data for historic and prehistoric populations to compare are available.

Specimens came from seven medieval cemeteries located throughout today’s Poland, and have been excavated recently. Teeth stored at low temperature underwent procedures generally accepted for aDNA isolation, performed automatically (MagNa Pure, Roche) at least two times on different teeth of each individual. Only the samples represented by collagen quantity above 2% dry weight, negative result of appropriate mock controls throughout isolation and amplification procedures, with successfully cloned (Amersham) and sequenced (AB 310) PCR products have been considered as authentic ancient templates. Moreover, we have applied NspI restriction analysis as a method for recognition and retrieval of undamaged ancient sequences.

The results show rapid increase in PRNP allele A frequency (Met 129) since the beginning of the Second Millennium (0.51 v. 0.65), accompanied by slight drop in heterozygotes (0.49 v. 0.39) and significant rise in Met homozygotes (0.27 v. 0.45).

As compared to present Polish as well as present European PRNP alleles frequency, medieval specimens provided the data which suggest altered mode of PRNP alleles transmission within last 35-40 generations. Although the nature of mechanism leading to observed changes is unclear, the impact of demographic factors is probably the most pronounced one affecting the process of local fluctuations of Met allele spreading out. However, the effect of selection processes should also be considered. This work is being supported by grant from Ministry of Science and Higher Education

Mice and Vikings

Eleanor Jones1
1 Department of Biology, University of York, Heslington, YO10 5DD, United Kingdom
Originally native to the northern Indian subcontinent and the Middle East, house mice (Mus musculus) have spread to their current near global distribution by exploiting a commensal niche with humans, originally in agrarian settlements. Mice also owe their current distribution pattern to human movements: they have reached the areas they now inhabit by being accidentally transported with grain and livestock foods. This close association between mice and humans means we can use information from the current genetic distribution of house mice to make inferences about past human colonisations and cultural linkages. In this study, we used mitochondrial DNA sequences from modern house mice in Great Britain, France, Ireland, Iceland, the Faeroe Islands and Norway to identify patterns in the their distribution, and tie these in to historic human migrations. The mice appear to be telling us about Norse Viking colonisations, and add a useful source of information to complement archaeological and historical data.

East Asia & Pacific

Genetic relationship of Human Skeletal Remains from an archaeological cemetery

Sang Hyun Jee 1, Yun Ji Kim 1, Yong Jae Chung1 & Min Seok Seo 1

1 Conservation Science Division, National Research Institute of Cultural Heritage, 472 Munji-dong, Yuseong-gu, Daejeon, 305-380, South Korea

We carried out genetic analyses of human skeletal remains from cemetery of a historic site, Myeong-arm-ri of Asan in South Korea. According to archaeological evidences, this site had been constructed from the Neolithic Age to the Joseon Dynasty. Twenty one human skeletons excavated from thirty pit tombs that have outer coffin build up into plaster dated to the Joseon Dynasty (14-19th century). To identify the genealogy and traditional burial pattern were assessed using mitochondrial DNA (mtDNA) and Y chromosomal STRs. We take cautious to avoid erroneous recombination by the segmental and modern contaminations were derived from researchers and all experimental stages. We sequenced the segmental amplicons of the hyper variable regions (HVRs) of mtDNA, and appointed relevant haplogroups according to the sequence polymorphism using the known mtDNA database. We also applied variable short tandem repeat (STR) marker in Y chromosome to understand paternal lineage and kinship among the burials. Especially, we interested in the four burying together and examined genetic relationship more closely between two individuals.

Not quite in the bag: A systematic bioarchaeological approach to the question of South American chickens origins

Greger Larson
1 Dept. of Archaeology, Durham University, South Road, DH1 3LE, UK

Though chickens were undoubtedly introduced into the American continents by the Spanish after their arrival in the 15th century, there is an ongoing debate as to the possible that Polynesians traveling across the Pacific introduced chickens to South America before Europeans did so. A recent publication concluded on the basis of ancient DNA extracted from an archaeological Chilean chicken bone that domestic fowl were present in a pre-Columbian context and that those chickens possessed a Polynesian genetic signature. In order to test this hypothesis, we generated mitochondrial DNA control region sequences from 41 modern, native Chilean specimens and analyzed them within a database consisting of both the published ancient DNA sequences and ~1,000 globally distributed modern domestic chicken sequences. Our modern Chilean sequences cluster closely with haplotypes predominantly distributed amongst European, Indian, and Southeast Asian chickens, consistent with a European genetic origin. The previously published, apparently pre-Columbian, Chilean specimen and seven pre-European Polynesian specimens, also cluster with the same European/Indian subcontinental/Southeast Asian sequences, providing, at this stage, no support for a Polynesian introduction of chickens to South America. Ancient DNA sequences from two archaeological sites on Easter Island, however, cluster with chickens found in Island Southeast Asia, and may represent a genetic signature of an early Polynesian dispersal as far as Easter Island. Lastly, we modeled the potential marine carbon contribution to the Chilean archaeological specimen (thus revising the derived date of the specimen) which cast doubt on the pre-Columbian age of the chicken remains. Definitive proof of a pre-Columbian introduction will require excavating more chicken bones, and further analyses of ancient DNA and radiocarbon data from Chilean and Polynesian archaeological excavations.

A New Bioarchaeological Clue for the DongHu Nationality

ZHANG Quan-chao, CHANG E，ZHU Hong

( Research Center f or Chinese Frontier A rchaeology , Jilin University , Changchun , Jilin , 130012 , China)

Abstract: DongHu nationality is a branch the Hu population who acted actively in the northeast of Yan. Whilst the remains of DongHu had not been confirmed for a long time, The tombs discovered in linxi Jinggouzi site in 2002 suggested a new clue for exploring the remains of Donghu in Chifeng area. These tombs not only meet the condionons in relation to DongHu in the aspects of time and region, but also conformed to DongHu characteristics of economic style and ethic features. In this article, human remains unearthed from the Spring and Autumn-Warring states cemetery at the Jinggouzi site in Linxi county, Inner Mongolia were studied. The morphological features of Jinggouzi group crania show that the racial type is closely related to the modern North Asiatic Mongoloids, and some physical characteristics of these skulls are closer to the ancient XianBei population in the north China and the modern Mongol. Ancient DNA sequences from ancient human remains have provided very important information on human evolution, blood relationship and migration, making ancient DNA research an important field of molecular anthropology. This study illustrates ancient DNA extraction, amplification and sequencing of five individuals of an ancient population buried in the west cemetery at Jinggouzi site in Inner Mongolia. A phylogenetic tree, a two-dimensional PC plot and MDS plot are constructed using mtDNA sequences from the ancient population and several modern Eurasian populations. However, the application of the techniques of ancient DNA allows us to explore the fasten source of the ancient population. Therefore, the genetic evidence raise the important meaning for the study of archeological culture in the east of Inner Mongolia during Spring and Autumn-Warring states. In addition, this new study which based on genetics and traditional archaeology on the development of populations from the north steppes of our country during Spring and Autumn-Warring states, provides precious data. In this study, we examine Jinggouzi population paleodiet using stable isotope ratios of carbon and nitrogen in bone collagen. Nitrogen isotope ratios of bone collagen show that Jinggouzi ancient population in primarily ate animal products with only a small amount of plant products. Carbon isotope ratios of bone collagen show that most plant products come from C₄ plant.

Physical anthropology

Obtaining population genetics data via non-destructive means: a three-dimensional analysis of human craniofacial morphology

Sabrina B. Sholts1, Sebastian Wärmländer2, & Phillip L. Walker3
1 Department of Anthropology, University of California at Santa Barbara, Department of Anthropology, University of California, Santa Barbara, CA 93106, USA

2 Division of Biophysics, Arrhenius Laboratories for Natural Science, Stockholm University, 10691 Stockholm, Sweden

3 Department of Anthropology, University of California at Santa Barbara, Department of Anthropology, University of California, Santa Barbara, CA 93106, USA

In this study, shapes extracted from the human craniofacial skeleton were used to investigate the genetic heritabilities of morphological traits. Three-dimensional point data was collected from human crania with a 3D laser scanner and used to render complete 3D surface models of the original skeletal material. 3D data analysis software was used to digitally slice the cranial models with geometric planes defined by traditional craniometric landmarks. The cross-sections produced by these planes yielded contours of cranial outlines for different craniofacial features. Using elliptical Fourier transforms, the contours were parametrized into series of Fourier coefficients, which, due to their inherent orthogonality, form suitable input parameters for statistical analysis. Principal components analysis (PCA) was employed to differentiate population groups based on shape differences in various aspects of cranio-facial skeletal morphology. This method can yield population genetics data and information on probable ancestral affinity using non-destructive analysis of human remains and with greater accuracy than with traditional craniometric studies of metric and non-metric traits. The application of this method to human skeletal collections can elucidate genetic relationships in past populations and improve our understanding of their archaeological contexts. This non-invasive method also offers a viable alternative for determining ancestral affinities between groups and individuals in cases where DNA testing is not possible, due to either the necessary destruction of bone required for DNA analysis or the degraded condition of the material.