New aDNA capture method (plus some data on ancient individuals from Bulgaria, Denmark, and Peru)

This seems to present an alternative method for capture of ancient DNA libraries than the one used on the Tianyuan individual. It is mostly a methods paper, but also has some initial analysis of some ancient individuals. From the paper:

We were able to tentatively call mtDNA haplogroups for these samples (Table S1). The two Bulgarian Iron Age individuals (P192-1 and T2G5) fell into haplogroups U3b and HV(16311), respectively. Haplogroup U3 is especially common in the countries surrounding the Black Sea, including Bulgaria, and in the Near East, and HV is also found at low frequencies in Europe and peaks in the Near East.41 The three Peruvian mummies fell into haplogroups B2, M (an ancestor of D), and D1, all derived from founder Native American lineages and previously observed in both pre-Columbian and modern populations from Peru. 

P192-1 was an Iron Age Thracian; T2G5 was from an Iron Age Thracian tumulus burial.

Also:

For the Peruvian mummies, we also included 10 Native American individuals from Central and South America in the PCA (Figures 3E and 3F). Interestingly, all of the mummies fell between the Native American populations (KAR, MAY, AYM) and East Asian populations (JPT, CHS, CHB), as would be expected for a nonadmixed Native American individual (Figures 3E, 3F, and S2). These mummies belonged to the pre-Columbian Chachapoya culture, who, by some accounts, were unusually fair-skinned,39 suggesting a potential for pre- Columbian European admixture. However, based on our preliminary results, these individuals appear to have been ancestrally Native American. 

The Peruvian mummies were from 1000-1500AD, so it's not very surprising that they don't appear to have European admixture and to be "ancestrally Native American".

Hopefully a more complete analysis of this data and production of more data with this method will follow in the future.

The American Journal of Human Genetics (2013), http://dx.doi.org/10.1016/j.ajhg.2013.10.002

Pulling out the 1%: Whole-Genome Capture for the Targeted Enrichment of Ancient DNA Sequencing Libraries

Meredith L. Carpenter et al.

Most ancient specimens contain very low levels of endogenous DNA, precluding the shotgun sequencing of many interesting samples because of cost. Ancient DNA (aDNA) libraries often contain less than 1% endogenous DNA, with the majority of sequencing capacity taken up by environmental DNA. Here we present a capture-based method for enriching the endogenous component of aDNA sequencing libraries. By using biotinylated RNA baits transcribed from genomic DNA libraries, we are able to capture DNA fragments from across the human genome. We demonstrate this method on libraries created from four Iron Age and Bronze Age human teeth from Bulgaria, as well as bone samples from seven Peruvian mummies and a Bronze Age hair sample from Denmark. Prior to capture, shotgun sequencing of these libraries yielded an average of 1.2% of reads mapping to the human genome (including duplicates). After capture, this fraction increased substantially, with up to 59% of reads mapped to human and enrichment ranging from 6- to 159-fold. Furthermore, we maintained coverage of the majority of regions sequenced in the precapture library. Intersection with the 1000 Genomes Project reference panel yielded an average of 50,723 SNPs (range 3,062–147,243) for the postcapture libraries sequenced with 1 million reads, compared with 13,280 SNPs (range 217–73,266) for the precapture libraries, increasing resolution in population genetic analyses. Our whole-genome capture approach makes it less costly to sequence aDNA from specimens containing very low levels of endogenous DNA, enabling the analysis of larger numbers of samples.

Link (pdf)

European hunter-gatherers acquired pigs with Near Eastern and European mtDNA

This is a nice demonstration of transfer of domesticated animals from Neolithic farmers to European hunter-gatherers. (Red=European, Yellow=Near Eastern).

Related: Ottoni et al. (2012).

Nature Communications 4, Article number: 2348 doi:10.1038/ncomms3348

Use of domesticated pigs by Mesolithic hunter-gatherers in northwestern Europe

Ben Krause-Kyora et al.

Mesolithic populations throughout Europe used diverse resource exploitation strategies that focused heavily on collecting and hunting wild prey. Between 5500 and 4200 cal BC, agriculturalists migrated into northwestern Europe bringing a suite of Neolithic technologies including domesticated animals. Here we investigate to what extent Mesolithic Ertebølle communities in northern Germany had access to domestic pigs, possibly through contact with neighbouring Neolithic agricultural groups. We employ a multidisciplinary approach, applying sequencing of ancient mitochondrial and nuclear DNA (coat colour-coding gene MC1R) as well as traditional and geometric morphometric (molar size and shape) analyses in Sus specimens from 17 Neolithic and Ertebølle sites. Our data from 63 ancient pig specimens show that Ertebølle hunter-gatherers acquired domestic pigs of varying size and coat colour that had both Near Eastern and European mitochondrial DNA ancestry. Our results also reveal that domestic pigs were present in the region ~500 years earlier than previously demonstrated.

Link

Genomic history of Denmark

An announcement from the GeoGenetics centre:

The Genomic History of Denmark.

The centre has received a 36 mill. DKK grant from Univ. of Copenhagen's dedicated 2016-program. Researchers from GeoGenetics in close cooperation with collegues from the National Museum of Denmark and institutes at the University of Copenhagen will make Denmark the first country in the world to map its evolutionary, demographic and health history - from the earliest settlers through to modern times.

DNA and proteins extracted from a Danish collection of archaeological skeletons from the Older Stone Age (5000-3000 BC) will be analysed in order to learn more about the Danish cultural heritage and health history.

Professor and director of the Centre for GeoGenetics Eske Willerslev is project leader.

Skull trauma in Neolithic Scandinavia

I would be interested to know how this Neolithic sample might differ from more recent ones. My limited understanding suggests that between-male violence often has a signalling component whereby an individual's or group's dominance over another is asserted, so the fight often does not go all the way to death, but only until the status quo is manifested by the controlling party or toppled by a challenger.

This type of "signalling" aspect of violent behavior does not apply to male-to-female violence because of the physical strength inequality between the sexes. Indeed, as with violence towards children or the elderly, male-to-female violence may have a "reverse signalling" effect, because it suggests that the perpetrator is unable to fight with "the strong" and is only able to assert physical dominance in "easy fights". On the other hand, such "easy fights" might be more abundant if perpetrators tend to enter fights they can win.

Fight-to-the-death, on the other hand, may occur either by accident (e.g., when the aim is to assert dominance, but the killer underestimates the tolerance of the victim), or by intent (when the aim is physical annihilation, either because reconciliation with the victim is perceived to be impossible, or because the victim's death may help keep other challengers in check).

There may be lots to learn about gender roles and social hierarchy from large palaeoanthropological samples. For example, how much did ideology affect secular patterns of interpersonal violence, and how much did changes in weapon technology (e.g., from Neolithic to Bronze, Iron, and more recently firearms).

Am J Phys Anthropol DOI: 10.1002/ajpa.22192

Patterns of violence-related skull trauma in neolithic southern scandinavia

Linda Fibiger et al.

This article examines evidence for violence as reflected in skull injuries in 378 individuals from Neolithic Denmark and Sweden (3,900–1,700 BC). It is the first large-scale crossregional study of skull trauma in southern Scandinavia, documenting skeletal evidence of violence at a population level. We also investigate the widely assumed hypothesis that Neolithic violence is male-dominated and results in primarily male injuries and fatalities. Considering crude prevalence and prevalence for individual bones of the skull allows for a more comprehensive understanding of interpersonal violence in the region, which is characterized by endemic levels of mostly nonlethal violence that affected both men and women. Crude prevalence for skull trauma reaches 9.4% in the Swedish and 16.9% in the Danish sample, whereas element-based prevalence varies between 6.2% for the right frontal and 0.6% for the left maxilla, with higher figures in the Danish sample. Significantly more males are affected by healed injuries but perimortem injuries affect males and females equally. These results suggest habitual male involvement in nonfatal violence but similar risks for both sexes for sustaining fatal injuries. In the Danish sample, a bias toward front and left-side injuries and right-side injuries in females support this scenario of differential involvement in habitual interpersonal violence, suggesting gendered differences in active engagement in conflict. It highlights the importance of large-scale studies for investigating the scale and context of violence in early agricultural societies, and the existence of varied regional patterns for overall injury prevalence as well as gendered differences in violence-related injuries.

Link

Ancient Nordic mtDNA (Melchior et al. 2010)

The reduction of mtDNA haplogroup I in modern Scandinavians has been observed before (by the same author). Inferences from the 2 Bell Beaker and 1 Bronze Age samples which belong to U subgroups should be cautious, however these contrast with later groups as well as with the earlier Neolithic Scandinavian TRB samples. Table 5 has haplogroup frequencies in various age-place groups. From the paper:

Table 5 shows the occurrence of haplogroups among ancient Danes and Britons and modern Danes and Scandinavians. Using G-tests, no significant deviations were observed among the extant populations or between the ancient Britons and the ancient Danes, despite the two ancient population samples show a surplus of Hg T and Hg I, respectively. We have previously observed a high frequency of Hg I's among Iron Age villagers (Bøgebjerggård) and individuals from the early Christian cemetery, Kongemarken [16], [17]. This trend was also found for the additional sites reported here, Simonsborg, Galgedil and Riisby. The overall frequency of Hg I among the individuals from the Iron Age to the Medieval Age is 13% (7/53) compared to 2.5% for modern Danes [35]. The higher frequencies of Hg I can not be ascribed to maternal kinship, since only two individuals share the same common motif (K2 and K7 at Kongemarken). Except for Skovgaarde (no Hg I's observed) frequencies range between 9% and 29% and there seems to be no trend in relation to time.

There are two main explanations for the reduction in haplogroup I frequency: (a) negative selection and/or (b) the movement of non-I bearing populations into the region of interest. Unless selection occurred very recently (in the last millennium), the lack of a temporal trend adds some weight in favor of (b) and contra (a).

Of interest:

Several haplogroups which are rare or absent among the extant population of southern Scandinavia were observed. Hg's R0a and U7 have been discussed previously [15], [17]. Here we note the finding of Hg N1a in the Medieval Riisby (Table 3), which seems to be common among early European LBK farmers [10], a rare Hg T2 motif in the Iron Age settlement Simonsborg (Table 2) and Hg U5a and Hg U4 at the Early Bronze Age site Bredtoftegård and Neolithic Damsbo (Table 1).

A recent paper on mtDNA haplogroup R0a.

A main conclusion from this paper is that the mtDNA gene pool does not appear to change "monotonically" with time, as the Neolithic Bell Beaker and Bronze Age groups resemble Mesolithic ones rather than the Neolithic TRB. Thus, it is safe to say that simple one-time admixture scenaria between "Paleolithic" and "Neolithic" gene pools grossly oversimplify reality.

The more we learn about prehistory, the less we can believe in the paradigm of static people changing their subsistence, technology, language from the Paleolithic to the present. Migrationism is overdue for a comeback as an explanatory tool for the plethora of unexpected results that the bones of ancient humans present us with.

The persistence of mtDNA-U gene pools down to the Bronze Age leads the authors to consider the Iron Age as the origin of the modern Scandinavian mtDNA gene pool:

However, the frequency of Hg U4 and U5 declines significantly among our more recent Iron Age and Viking Age Danish population samples to the level observed among the extant Danish population. Our study therefore would point to the Early Iron Age and not the Neolithic Funnel Beaker Culture as suggested by Malmström et al. (2009) [14], as the time period when the mtDNA haplogroup frequency pattern, which is characteristic to the presently living population of Southern Scandinavia, emerged and remained by and large unaltered by the subsequent effects of genetic drift.

I find that a reasonable suggestion, as it was in the Iron Age that the Germanic language group seems to have emerged in southern Scandinavia and northern Germany, and started to experience its demographic expansion that rendered it one of the largest in modern Europe. So, it makes sense that the mtDNA composition of that age would persist down to the present-day inhabitants.

Related:

• Ancient Viking mtDNA from Denmark
• Iron Age, Viking Age, and Eskimo mtDNA
• Ancient mtDNA from Iron Age Denmark
• mtDNA of an early Danish sample
• Modern Scandinavians descended (maybe) from Neolithic TRB but not Mesolithic Pitted Ware ancestors
• Some mtDNA links between Asia and Europe

PLoS ONE 5(7): e11898. doi:10.1371/journal.pone.0011898

Genetic Diversity among Ancient Nordic Populations

Linea Melchior et al.

Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13%) than among extant Danes and Scandinavians (~2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type “diluted” by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300–3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.

Link

NordicDB paper on Finns, Danes, and Swedes

On the left is an MDS plot using ~45k SNPs. Some explanation on the datasets: CAPS are Swedish; SGENE and MS are Finnish (Helsinki region); Aneurysm is Finnish (Helsinki and Kupio).

A striking feature of the plot is the distinctiveness of the different Finish samples (light vs. dark brown points). This is not so difficult to explain if one considers that the light brown squares (DGI-FIN) are from Botnia. This parallels the results of Salmela et al. (2008) or Jakkula et al. (2008) in underscoring the internal structure of the population of Finland

The familiar V shape was also observed in the PCA produced by McEvoy et al. (2009) or Nelis et al. (2009). In my opinion, it is produced by the differential representation of the two main population elements of the Nordic countries, namely the Germanic and Finnic elements.

Here is the website of NordicDB.

European Journal of Human Genetics doi: 10.1038/ejhg.2010.112

NordicDB: a Nordic pool and portal for genome-wide control data

Monica Leu et al.

A cost-efficient way to increase power in a genetic association study is to pool controls from different sources. The genotyping effort can then be directed to large case series. The Nordic Control database, NordicDB, has been set up as a unique resource in the Nordic area and the data are available for authorized users through the web portal (http://www.nordicdb.org). The current version of NordicDB pools together high-density genome-wide SNP information from ~5000 controls originating from Finnish, Swedish and Danish studies and shows country-specific allele frequencies for SNP markers. The genetic homogeneity of the samples was investigated using multidimensional scaling (MDS) analysis and pairwise allele frequency differences between the studies. The plot of the first two MDS components showed excellent resemblance to the geographical placement of the samples, with a clear NW–SE gradient. We advise researchers to assess the impact of population structure when incorporating NordicDB controls in association studies. This harmonized Nordic database presents a unique genome-wide resource for future genetic association studies in the Nordic countries.

Link

Why Some Women Look Young for Their Age (Gunn et al. 2009)

On the left facial composites of younger/older (left/right) monozygotic/dizygotic twins (top/bottom).

PLoS ONE doi:10.1371/journal.pone.0008021

Why Some Women Look Young for Their Age

David A. Gunn et al.

Abstract

The desire of many to look young for their age has led to the establishment of a large cosmetics industry. However, the features of appearance that primarily determine how old women look for their age and whether genetic or environmental factors predominately influence such features are largely unknown. We studied the facial appearance of 102 pairs of female Danish twins aged 59 to 81 as well as 162 British females aged 45 to 75. Skin wrinkling, hair graying and lip height were significantly and independently associated with how old the women looked for their age. The appearance of facial sun-damage was also found to be significantly correlated to how old women look for their age and was primarily due to its commonality with the appearance of skin wrinkles. There was also considerable variation in the perceived age data that was unaccounted for. Composite facial images created from women who looked young or old for their age indicated that the structure of subcutaneous tissue was partly responsible. Heritability analyses of the appearance features revealed that perceived age, pigmented age spots, skin wrinkles and the appearance of sun-damage were influenced more or less equally by genetic and environmental factors. Hair graying, recession of hair from the forehead and lip height were influenced mainly by genetic factors whereas environmental factors influenced hair thinning. These findings indicate that women who look young for their age have large lips, avoid sun-exposure and possess genetic factors that protect against the development of gray hair and skin wrinkles. The findings also demonstrate that perceived age is a better biomarker of skin, hair and facial aging than chronological age.

Link

Ancient Viking mtDNA from Denmark

Table 1 has the data from this study, Table S3 previous Danish Iron Age and Viking results.

Related:
Iron Age, Viking Age, and Eskimo mtDNA
Ancient mtDNA from Iron Age Denmark
mtDNA of an early Danish sample

UPDATE: Frequencies of mtDNA haplogroup I several populations in Quintana-Murci et al. (pdf). The higher frequencies appear in Sindhi from Pakistan (8.7%), Kurds from western Iran and Turks from eastern and western Azerbaijan (both 5%), and Mazandarians from northern Iran (4.5%). In Russians from Oryol oblast (8.3%) (Ann. Hum. Genet. (2001), 65, 63-78). Various European groups (table).

UPDATE (June 10): From a press release related to this by the University of Copenhagen:

At the beginning of the Danish iron age, the roman legions were based as far north as the river Elbe (on the border of northern Germany) and it is thought that the man of arabian descent found in the burial grounds in Southern Zealand would have either been a slave or a soldier in the roman army. It is probable that he possessed skills or special knowledge, which the people in Bøgebjerggård or Skovgaard settlements could make use of, or he could have been the descendant of a female of arabian origin, who for reasons unknown, had crossed the river Elbe and settled down with the inhabitants of Zealand.

"This discovery is comparable to the findings of a colleague of mine, who found a person of siberian origin on the Kongemarke site," continues scientist, Linea Melchior. He was buried on consecrated ground, just as the circumstances of the arab man's burial was identical to that of the locals. The discovery of the arab man indicates that people from distant parts of the world could be and were absorbed in Danish communities.

PLoS ONE 3(5): e2214. doi:10.1371/journal.pone.0002214

Evidence of Authentic DNA from Danish Viking Age Skeletons Untouched by Humans for 1,000 Years

Linea Melchior et al.

Abstract

Background

Given the relative abundance of modern human DNA and the inherent impossibility for incontestable proof of authenticity, results obtained on ancient human DNA have often been questioned. The widely accepted rules regarding ancient DNA work mainly affect laboratory procedures, however, pre-laboratory contamination occurring during excavation and archaeological-/anthropological handling of human remains as well as rapid degradation of authentic DNA after excavation are major obstacles.

Methodology/Principal Findings

We avoided some of these obstacles by analyzing DNA from ten Viking Age subjects that at the time of sampling were untouched by humans for 1,000 years. We removed teeth from the subjects prior to handling by archaeologists and anthropologists using protective equipment. An additional tooth was removed after standard archaeological and anthropological handling. All pre-PCR work was carried out in a “clean- laboratory” dedicated solely to ancient DNA work. Mitochondrial DNA was extracted and overlapping fragments spanning the HVR-1 region as well as diagnostic sites in the coding region were PCR amplified, cloned and sequenced. Consistent results were obtained with the “unhandled” teeth and there was no indication of contamination, while the latter was the case with half of the “handled” teeth. The results allowed the unequivocal assignment of a specific haplotype to each of the subjects, all haplotypes being compatible in their character states with a phylogenetic tree drawn from present day European populations. Several of the haplotypes are either infrequent or have not been observed in modern Scandinavians. The observation of haplogroup I in the present study (<2% in modern Scandinavians) supports our previous findings of a pronounced frequency of this haplogroup in Viking and Iron Age Danes.

Conclusion

The present work provides further evidence that retrieval of ancient human DNA is a possible task provided adequate precautions are taken and well-considered sampling is applied.

Link

Iron Age, Viking Age, and Eskimo mtDNA

Thule culture Inuit was A2, Roman Iron Age Denmark (2000BP) was T2, and three Viking Age Icelanders were J, K, and H.

See also mtDNA from Iron Age Denmark.

Journal of Archaeological Science
Volume 35, Issue 6, June 2008, Pages 1445-1452

On the elimination of extraneous DNA in fossil human teeth with hypochlorite

Jørgen Dissing, Margrét A. Kristinsdottir and Camilla Friis

Abstract

Elimination of extraneous DNA in fossil specimens is of paramount importance for the successful isolation and analysis of authentic DNA; this is especially true when the specimens are of human origin. Bones and teeth are commonly decontaminated with bleach containing the powerful oxidising hypochlorite ion. The procedures involve either submersion in or wiping with the chlorine agent. Using the radioactive isotope Cl³⁶ we showed that submersion of fossil teeth in solutions of small ions such as Cl⁻ or hypochlorite, ClO⁻, cause that they migrate right into the pulp. This may lead to the unwanted destruction of authentic DNA. However, using pairs of teeth from the remains of four ancient Europeans (1000–2000 YBP) as well as tooth and hair from an Inuit skull (>300 YBP) we provide evidence that at least some endogenous human fossil DNA survives in powdered pulp/dentin that has been submersed in 2% hypochlorite. Further, we show that powdered pulp/dentin deliberately contaminated with huge amounts of a 414 bp PCR product is effectively decontaminated by suspension in 2% hypochlorite for 5 min. Decontamination of fossil material from teeth may therefore be accomplished by a short direct action of hypochlorite on the powdered specimen rather than less controllable and less efficient external treatments of the whole specimen.

Link

Ancient mtDNA from Iron Age Denmark

Am J Phys Anthropol. 2007 Nov 28 [Epub ahead of print]

Rare mtDNA haplogroups and genetic differences in rich and poor Danish Iron-Age villages.

Melchior L, Gilbert MT, Kivisild T, Lynnerup N, Dissing J.

The Roman Iron-Age (0-400 AD) in Southern Scandinavia was a formative period, where the society changed from archaic chiefdoms to a true state formation, and the population composition has likely changed in this period due to immigrants from Middle Scandinavia. We have analyzed mtDNA from 22 individuals from two different types of settlements, Bøgebjerggård and Skovgaarde, in Southern Denmark. Bøgebjerggård (ca. 0 AD) represents the lowest level of free, but poor farmers, whereas Skovgaarde 8 km to the east (ca. 200-270 AD) represents the highest level of the society. Reproducible results were obtained for 18 subjects harboring 17 different haplotypes all compatible (in their character states) with the phylogenetic tree drawn from present day populations of Europe. This indicates that the South Scandinavian Roman Iron-Age population was as diverse as Europeans are today. Several of the haplogroups (R0a, U2, I) observed in Bøgebjerggård are rare in present day Scandinavians. Most significantly, R0a, harbored by a male, is a haplogroup frequent in East Africa and Arabia but virtually absent among modern Northern Europeans. We suggest that this subject was a soldier or a slave, or a descendant of a female slave, from Roman Legions stationed a few hundred kilometers to the south. In contrast, the haplotype distribution in the rich Skovgaarde shows similarity to that observed for modern Scandinavians, and the Bøgebjerggård and Skovgaarde population samples differ significantly (P approximately 0.01). Skovgaarde may represent a new upper-class formed by migrants from Middle Scandinavia bringing with them Scandinavian haplogroups.

Link

Reversal of Flynn effect in Denmark

Danish IQ appears to have become lower over a 5-6 year period, providing some evidence that the Flynn effect (secular increase in IQ) not only has ceased to operate but may have actually reversed.

Intelligence (Article in Press)

Secular declines in cognitive test scores: A reversal of the Flynn Effect

Thomas W. Teasdale and David R. Owen

Abstract

Scores on cognitive tests have been very widely reported to have increased through the decades of the last century, a generational phenomenon termed the ‘Flynn Effect’ since it was most comprehensively documented by James Flynn in the 1980's. There has, however, been very little evidence concerning any continuity of the effect specifically into the present century. We here report data from a population, namely young adult males in Denmark, showing that whereas there were modest increases between 1988 and 1998 in scores on a battery of four cognitive tests–these constituting a diminishing continuation of a trend documented back to the late 1950's–scores on all four tests declined between 1998 and 2003/2004. For two of the tests, levels fell to below those of 1988. Across all tests, the decrease in the 5/6 year period corresponds to approximately 1.5 IQ points, very close to the net gain between 1988 and 1998. The declines between 1998 and 2003/4 appeared amongst both men pursuing higher academic education and those not doing so.

Link

The Evolution of adult height in Europe

From the paper:

From the evidence in Figure 3 and Figure 4 we can conclude for the Southern European countries that Greeks are the tallest for both males and females and Portuguese are the shortest ones in both cases. Both countries show a similar evolution profile in the period under consideration. At contrast, Spanish males and females for the last cohorts are growing more significantly than those in the other Southern European countries.

Economics & Human Biology In Press, Accepted Manuscript, Available online 1 March 2007,

The Evolution of Adult Height in Europe: A Brief Note

Jaume Garcia

Abstract

This paper presents new evidence on the evolution of adult height in 10 European countries for cohorts born between 1950 and 1980 using the European Community Household Panel (ECHP), which collects height data from Austria, Belgium, Denmark, Finland, Greece, Ireland, Italy, Portugal, Spain and Sweden. Our findings show a gradual increase in adult height across all countries. However, countries from Southern Europe (Greece, Italy, Portugal, and Spain) experienced greater gains in stature than those located in Northern Europe (Austria, Belgium, Denmark, Finland, Ireland, and Sweden).

Sub-Saharan African mtDNA admixture in several West Eurasian (Caucasoid) populations

The recent article on Etruscan mtDNA contains a useful overview table of mtDNA haplogroups in several West Eurasian (Caucasoid) populations, collected from both this study as well as the literature. Extracted from this table is the following table of mtDNA L (Sub-Saharan African) sequences in the listed populations. Scroll down because blogger added a lot of vertical space above the table.

POPULATION	Sample Size	% L sequences
Palestinians	117	13.68
Jordan	494	12.55
Portugal-South	203	10.84
Iraq	116	9.48
Syria	328	9.15
Portugal-Center	203	6.4
Spain-North-West	216	3.7
Portugal-North	188	3.19
Latium	138	2.9
Non-Europeans	4739	2.85
Lebanon	176	2.84
Volterra	114	2.63
Kurds	82	2.44
Sicily	105	1.9
Turks	340	1.76
Andalusia	114	1.75
Spain-North-East	179	1.68
Casentino	122	1.64
Murlo	86	1.16
Crete	202	0.99
Marche	813	0.98
Tuscans	322	0.93
Finland	121	0.83
Europe (w/o Tuscans)	10589	0.79
Bulgaria	141	0.71
Bosnia	144	0.69
Spain-Center	148	0.68
Basque	156	0.64
England	335	0.6
Sardinia	370	0.54
Switzerland	228	0.44
Campania	313	0.32
France	332	0.3
Germany	335	0.3
Iran	436	0.23
Poland	542	0.18
Caucasus-North-West	1179	0.17
Apulia-Calabria	226	0
Armenia	191	0
Austria	99	0
Azerbaijan	48	0
Bavaria	249	0
Caucasus-North-East	820	0
Czech-Republic	83	0
Estonia	558	0
Georgia	412	0
Greece	155	0
Ireland	300	0
Latvia	299	0
Lemnos	60	0
Lombardy	177	0
Norway	556	0
Piedmont	169	0
Rhodes	42	0
Romania	94	0
Russia	397	0
Scotland	1199	0
Slovakia	129	0
Slovenia	104	0
Sweden-Denmark	75	0
Wales	92	0

Happy Danes

Why are Danes the world's happiest nation?

Earlier this year, Denmark came top in a world map of happiness (the UK ranked 41st out of 178 nations). And for more than 30 years it has ranked first in European satisfaction surveys. So what makes Danes so content?

Researchers in this week's Christmas issue of the BMJ decided to find out why life satisfaction in Denmark substantially exceeds that in Sweden and Finland, the two countries most similar to Denmark.

Their hypotheses range from the unlikely (hair colour, genes, food and language) to the more plausible, such as family life, health and a prosperous economy.

However, their analysis points to two explanatory factors. Firstly, winning the 1992 European Football Championship put Danes in such a state of euphoria that the country has not been the same since. This may explain the high level of life satisfaction in Denmark after 1992, they write.

Secondly, while Danes are very satisfied, their expectations for the coming year are rather low. In contrast, Italy and Greece, which rank low on life satisfaction, rank high on expectations for the year to come, together with Swedes and Finns.

The causes of the stolid depth of Danish wellbeing are undoubtedly multifactorial, they say. The Danish football triumph of 1992 has had a lasting impact, but the satisfaction of the Danes began well before 1992, albeit at a more moderate level. The key factor that explains this, and that differentiates Danes from Swedes and Finns, seems to be that Danes have consistently low (and realistic) expectations for the year to come.

So the key to happiness may lie in the fact that if you lower your expectations enough you might feel a bit better next Christmas, they conclude.

Population age structure and prosperity

Steve Sailer points me to an article by Malcolm Gladwell in the New Yorker. Gladwell makes the excellent point that the dependency ratio explains a country's prosperity:

This relation between the number of people who aren’t of working age and the number of people who are is captured in the dependency ratio. In Ireland during the sixties, when contraception was illegal, there were ten people who were too old or too young to work for every fourteen people in a position to earn a paycheck. That meant that the country was spending a large percentage of its resources on caring for the young and the old. Last year, Ireland’s dependency ratio hit an all-time low: for every ten dependents, it had twenty-two people of working age. That change coincides precisely with the country’s extraordinary economic surge.

...

Economists have long paid attention to population growth, making the argument that the number of people in a country is either a good thing (spurring innovation) or a bad thing (depleting scarce resources). But an analysis of dependency ratios tells us that what’s critical is not just the growth of a population but its structure. “The introduction of demographics has reduced the need for the argument that there was something exceptional about East Asia or idiosyncratic to Africa,” Bloom and Canning write, in their study of the Irish economic miracle. “Once age-structure dynamics are introduced into an economic growth model, these regions are much closer to obeying common principles of economic growth.”

I was extremely pleased to see this point being argued. I had made a similar observation back in 2003 in Fishing in the Pond of Correlation.

Let's take factor #1: Demographic Structure. I used % of population under age 15 as a proxy for this factor. The intuition goes that since children don't have the capacity (muscle or intellectual) to produce as much as adults, a nation with a large number of children will have a lower per capita income.

Indeed, there is a -0.71 correlation between % of population under 15 and per capita PPP, accounting for 50% of the variance of the dependent variable.

Roughly half the population in the world is women. Women get pregnant and while pregnant or rearing young children can't be as productive as men. So, we expect that nations where women have lots of children will have a lower per capita income, simply because half their population spends quite a lot of time being pregnant, breastfeeding or changing diapers. This is factor #2, which also relates to Demographic Structure.

Steve brings the example of Ukraine as an argument against the idea that population structure affects prosperity. I had actually observed this discrepancy in my original post:

Finally, I list the 10 countries whose per capita PPP is most overestimated by the model: Ukraine, Georgia, Bulgaria, Croatia, Cuba, Romania, Bosnia and Herzegovina, Moldova, Rep. of, Sri Lanka, Russian Federation

It is clear that adding "democracy" as a value, would help eliminate these residual errors. The 10 countries whose income is most underestimated are: Australia, Brunei Darussalam, Switzerland, Denmark, Canada, Equatorial Guinea, Norway, Iceland, Ireland, United States

It is notable that many of these countries have abundant natural resources (e.g., Iceland, Norway, Brunei), special financial status (Switzerland), or a large territory with respect to their population (Canada, Australia).

So, yes, demographic age structure is indeed a major determinant of economic prosperity as measured by per capita PPP, more so, once we control for factors such as recent history or natural resources.

Update (Aug 28): I have re-uploaded the data file in the old entry; it was missing from the old blog archive in 50webs. The link to the UNDP report from 2003 is also outdated. Here is a link to the latest 2006 report.

Here are the statistics on population under age 15. and PPP per capita from the UNDP website.

After repeating the calculations, I have found a correlation of -0.69 between population under age 15 and GDP per capita (US$ PPP). The scatterplot is even more informative.



It is clear that countries with large populations of dependents (on the right of the figure) all have small per capita income. Other factors may play a bigger role in countries with moderate and small populations of dependents.

The outliners in the graph are Equatorial Guinea and Luxembourg. If they are removed, the correlation becomes even more pronounced (-0.73)



I have often tried tried to show (e.g., for disease or hair dye sales) that we do not need to postulate elaborate explanations for phenomena when simpler ones suffice.

In this case, the lower per-capita GDP is a logical consequence of a high population of children: Per-capita GDP can be expressed as (Number of productive individuals)*(Average Individual Production)/(Total Population). Countries with a great number of children are expected to have a low (Number of productive individuals)/(Total Population Ratio), or conversely a high dependency ratio, and hence we expect them to have a low per capita GDP! This is a logical consequence and requires no assumptions about, say, the relative ability of different populations.

So, why should we bother with Lynn-ian speculations about intelligence and prosperity which depend on the unsubstantiated assumption of substantial genetic differences in cognitive ability among major races when a simpler model, which makes no such assumptions is able to capture the data as well, or even better?

Update II: A reader makes the interesting point that children, rather than dependents are the critical parameter. I have calculated the correlation between GDP per capita (US$ PPP) and population over 65 (without the outliers mentioned above) and obtained a value of +0.7, consistent with the idea that people in prosperous societies live longer.

Then I added up the fraction of people age less than 15 with that more than 65, to obtain a total fraction of the population that is expected to be "dependent" on the productive population between ages 15 and 65. The new correlation is -0.66. Thus, both the fraction of the productive population (aged 15 to 65) as well as the fraction of the adult population (aged 15+) both have roughly the same explanatory power.

Update III (Aug 29): Here is a comment I left in Jane Galt's topic on the subject:

Observable GDP/capita is not caused by any single factor. However, it is partially caused by demographic structure. By "caused" I mean that if we change the variable "dependency ratio" then we expect to immediately and predictably change the variable "GDP per capita".

Incidentally, as I have mentioned in my blog, the reduction in per capita income is not caused only directly from the smaller fraction of active individuals: an even smaller fraction of individuals can really be active, since a substantial part of them, especially young mothers, spend a lot of time in activities of little economic value.

For example, imagine a toy society in which active individuals produce 100 units. If one society has 50% dependents, and another 25% dependents, then we expect the per capita income of the first one to be 50 and of the second one to be 75. But, the first society also has lots of individuals who do not produce a lot because they take care of the dependent population. If, say, 2 dependents use up the resources of an active individual, then the "real" active fraction in the first population will be 25%, and 62.5% in the second one, and the corresponding per capita income will of course be 25 and 62.5. Thus, even though individuals produce exactly the same in both societies, demographic factors cause one to exhibit 2.5 more per capita GDP than the other.

The questionable contribution of the Neolithic and the Bronze Age to European craniofacial form (?)

C. Loring Brace and colleagues have published a new paper in PNAS which examines several populations from West Eurasia and Africa based on 24 cranial measurements.

The first canonical variate (horizontal) clearly separates the Niger-Congo group from the other populations:



According to Brace et al:

When the samples used in Fig. 1 are compared by the use of canonical variate plots as in Fig. 2, the separateness of the Niger-Congo speakers is again quite clear. Interestingly enough, however, the small Natufian sample falls between the Niger-Congo group and the other samples used. Fig. 2 shows the plot produced by the first two canonical variates, but the same thing happens when canonical variates 1 and 3 (not shown here) are used. This placement suggests that there may have been a Sub-Saharan African element in the make-up of the Natufians (the putative ancestors of the subsequent Neolithic), although in this particular test there is no such evident presence in the North African or Egyptian samples. As shown in Fig. 1, the Somalis and the Egyptian Bronze Age sample from Naqada may also have a hint of a Sub-Saharan African component. That was not borne out in the canonical variate plot (Fig. 2), and there was no evidence of such an involvement in the Algerian Neolithic (Gambetta) sample.

Brace et al. also combined samples into regional groups. The canonical variate plot again shows the separate of the Niger-Congo group, and the intermediacy of the Natufians between West Eurasians and North/East Africans and Eurasians.



The raw Mahalanobis distances are quite informative.



It can be easily seen that the Niger-Congo have high distances from all other populations, except Northeast Africans. Northeast Africans are however closer to Late Prehistoric Eurasians and Modern Europeans than to the Niger-Congo group. This, once more, establishes the intermediacy of Northeast Africans between Caucasoids and Sub-Saharan Africans.

All populations except the Niger-Congo and the Natufians are close to each other. The Natufians have very high distances from other samples. Their closest neighbors are first, Late Prehistoric Eurasia, and second, Niger-Congo.

According to Brace:

The generally high D2 values for the Natufian sample in Table 3 are almost certainly a reflection of the very small sample size.

The Natufian sample consisted of only 4 individuals. Thus, it appears that the high distances of the Niger-Congo group are indicative of its biological distinctiveness, whereas the high distances of the Natufians are due to the small sample size.

Brace's conclusion is stated in conditional form:

If the Late Pleistocene Natufian sample from Israel is the source from which that Neolithic spread was derived, then there was clearly a Sub-Saharan African element present of almost equal importance as the Late Prehistoric Eurasian element. At the same time, the failure of the Neolithic and Bronze Age samples in central and northern Europe to tie to the modern inhabitants supports the suggestion that, while a farming mode of subsistence was spread westward and also north to Crimea and east to Mongolia by actual movement of communities of farmers, the indigenous foragers in each of those areas ultimately absorbed both the agricultural subsistence strategy and also the people who had brought it.

The "if" portion of the statement is problematic. While Natufians are widely acknowledged as a culture anticipating the arrival of the Neolithic, they were not the first Neolithic agriculturalists, nor where they the immediate source of the transmission of agriculture. According to Pinhasi and Pluciennik (CURRENT ANTHROPOLOGY Volume 45, Number S4, August-October 2004):

Analysis of the material suggests that there was considerable morphological heterogeneity among the earliest farmers of the Levant belonging to the Pre-Pottery Neolithic but that similar variability is generally not seen among the earliest mainland agriculturalists of south-eastern Europe. We propose that this may be explained by the existence of a genetic "bottleneck" among Anatolian populations and that it supports models of the largely exogenous origin of many early Neolithic populations in this region.

Thus, the sample of 4 Natufian individuals does not represent the first pre-pottery Neolithic populations, and moreover, it does not represent the immediate source of the Neolithic in Europe, which was that of the Neolithic agriculturalists of Anatolia. As Pinhasi and Pluciennik state:

Analysis of morphological variability in the Near East and Europe (here and in Pinhasi 2003) suggests that the Epipalaeolithic populations from the Natufian Levant were noticeably different to the Mesolithic populations described from the Danube Gorge, the western Mediterranean, and central Europe. No close similarities were observed between Early Neolithic and Mesolithic European groups in any of the regions studied, with the possible exception of Mediterranean Europe. However, neither were clear affinities observed between Epipalaeolithic Near Eastern groups and any other Neolithic or Mesolithic groups.

The last statement is important, because it establishes that the Natufians did not have clear associations with the first Neolithic groups. So, while they are believed to be pre-agricultural culturally they are not related to any Neolithic groups biologically.

Brace finds similarities between the ancient Neolithic culture-bearers and modern Mediterranean populations, which is no doubt accurate. On the other hand, in continental Europe, the "signal" of the Neolithic populations has been absorbed by the indigenous inhabitants. This is all fine, and agrees nicely with the picture presented sixty five years ago by Carleton Coon, whereby the invasion of Europe by gracile dolichomorphs (skeletally Mediterranean) populations was followed by a period of absorption and "re-emergence" of the Upper Paleolithic types and their mixtures with the Mediterraneans.

Indeed, the early inhabitants of Northern Europe were robust broad-faced Cro-Magnoids, unlike the gracile narrow-faced Mediterraneans which diffused through Central Europe from a proximate Southeastern European source. Brace studies Cro-Magnon to propose that:

If this analysis shows nothing else, it demonstrates that the oft-repeated European feeling that the Cro-Magnons are ‘‘us’’ (47) is more a product of anthropological folklore than the result of the metric data available from the skeletal remains.

Yes, this bizarre statement is not supported by his own data, which shows that Cro-Magnon shows that the Modern European sample is the only one to which Cro-Magnon is aligned to, however distantly:



The retention of the "Upper Paleolithic" signal in modern Europeans is quite impressive, since Europe's colonization did not cease with Cro-Magnon in the first Upper Paleolithic.

Cro-Magnon was a coarse-featured and robust skull atypical of modern Europeans, but one may still find individuals in Europe which resemble him: Brace et al. did not test for his resemblance to individuals. Moreover, he did not test Cro-Magnon against individual European populations. For example, Jantz and Owsley concluded that:

Using raw measurements, 6 of 8 express an affinity to Norse, and with the shape variables of Darroch and Mosimann ([1985]), 5 of 8 express a similarity to Norse. Using shape variables reduces the Mahalanobis distance, substantially in some cases. Typicality probabilities (Wilson, [1981]), particularly for the shape variables, show the crania to be fairly typical of recent populations. The results presented in Table 1 are consistent with the idea that Upper Paleolithic crania are, for the most part, larger and more generalized versions of recent Europeans. Howells ([1995]) reached a similar conclusion with respect to European Mesolithic crania.

UPDATE

I have sent the following questions to Dr. Brace regarding his study. If and when he responds, and if I am granted permission to publish his response, I will do so in these entry:

You state that Modern Europeans are not very closely linked to
Neolithic/Bronze Age Europeans, yet in Table 3, the distance between
"Modern Europe" and "Late Prehistoric Eurasia" is 1.87 which is the
lowest among all population pairs. "Late Prehistoric Eurasia" is
defined as:

"Then Neolithic samples from Denmark, England, France, Germany, and
Portugal were combined with Bronze Age samples from England, Jericho,
and Mongolia to make a ''Late Prehistoric Eurasia'' sample."

This would seem to indicate a strong affinity between Neolithic/Bronze
Age Europeans and modern Europeans.

Moreover, you state that "the oft-repeated European feeling that the
Cro-Magnons are ''us'' (47) is more a product of anthropological
folklore than the result of the metric data available from the
skeletal remains."

But, in Table 4, Cro-Magnon I shows mixed affiliations between Modern
Europe and Late Prehistoric Eurasia. The inability to fall completely
in either Modern Europe or LP Eurasia is not surprising, since Modern
Europe and Late Prehistoric Eurasia are extremely close to each other
(Table 3). So, the data in Table 4 seem to suggest that Cro-Magnon I
did in fact resemble modern Europeans and Late Prehistoric Eurasians.

I would be very interested in hearing your comments.

Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0509801102

The questionable contribution of the Neolithic and the Bronze Age to European craniofacial form

C. Loring Brace et al.

Many human craniofacial dimensions are largely of neutral adaptive significance, and an analysis of their variation can serve as an indication of the extent to which any given population is genetically related to or differs from any other. When 24 craniofacial measurements of a series of human populations are used to generate neighbor-joining dendrograms, it is no surprise that all modern European groups, ranging all of the way from Scandinavia to eastern Europe and throughout the Mediterranean to the Middle East, show that they are closely related to each other. The surprise is that the Neolithic peoples of Europe and their Bronze Age successors are not closely related to the modern inhabitants, although the prehistoric/modern ties are somewhat more apparent in southern Europe. It is a further surprise that the Epipalaeolithic Natufian of Israel from whom the Neolithic realm was assumed to arise has a clear link to Sub-Saharan Africa. Basques and Canary Islanders are clearly associated with modern Europeans. When canonical variates are plotted, neither sample ties in with Cro-Magnon as was once suggested. The data treated here support the idea that the Neolithic moved out of the Near East into the circum-Mediterranean areas and Europe by a process of demic diffusion but that subsequently the in situ residents of those areas, derived from the Late Pleistocene inhabitants, absorbed both the agricultural life way and the people who had brought it.

Link

Y chromosomes of Norway

This should be of interest to Norwegians and those suspecting "Viking" ancestry.



From the paper:

Haplogroup frequency distributions in the different Norwegian regions are presented (Fig. 1). The frequency of P*(xR1a) varied from 26% in the east to 45% in the south, BR*(xDE, J, N3, P) from 30% in the west to 42% in the south and R1a from 13% in the south to 32% in the middle. N3 was most frequent in the north (11%; 18.6% in the northernmost county Finnmark) and totally absent in the south. Haplogroup DE and J were rare in all regions. We observe a relatively high frequency of P*(xR1a) and R1a in the population sample from south-west and east, respectively.

Frequency of haplotypes:


Uralic admixture in the non-Saami Norwegian population:

Haplogroup N3 has been interpreted as a signature of Uralic Finno-Ugric speaking males migrating to northern Scandinavia about 4000–5000 years ago [9], [17], [35] and [60]. In the present study, N3 is observed at 4% in the overall population and at 11% in the northern region corresponding to 150,000 and 50,000 inhabitants, respectively. These numbers exceed the total number of Saami inhabitants, which is officially recognized as about 50,000 (http://www.sametinget.se). In northern Norway, the N3 percentage is 18.6% in Finnmark, 8.6% in Troms and 8.4% in Nordland (which are the three northernmost counties—Nordland being located to the south of the other two (Supplementary Data Online, Fig. 2)). There is thus a considerable pool of Saami and/or Finnish Y-chromosomes in the Norwegian population and particularly in the north.

Also of interest is the discovery of a new haplogroup:

A new haplogroup, not described earlier, was found in a single sample. Deduced from its biallelic type, it might represent a new 12f2 deletion within haplogroup P*(xR1a). The haplogroup it defines has been given the temporary name P*(xR1a)/12f2c (M. Jobling personal communication). Its haplotype composition is 15-10-17-24-10-13-14-11,14-12. There are already two known 12f2 deletions within hgJ and hgD2.

Forensic Sci Int. 2005 Dec 6; [Epub ahead of print] Links

Geographical heterogeneity of Y-chromosomal lineages in Norway.

Dupuy BM, Stenersen M, Lu TT, Olaisen B.

Y-chromosomal variation at five biallelic markers (Tat, YAP, 12f2, SRY(10831) and 92R7) and nine multiallelic short tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385I/II and DYS388) in a Norwegian population sample are presented. The material consists of 1766 unrelated males of Norwegian origin. The geographical distribution of the population sample reflects fairly well the population distribution around the year 1942, which is the median birth year of the index persons. Seven hundred and twenty-one different Y-STR haplotypes but 726 different lineages (Y-STRs plus biallelic markers) were encountered. We observed six known (P*(xR1a), BR(xDE, J, N3, P), R1a, N3, DE, J), and one previously undescribed haplogroup (probably a subgroup within haplogroup P*(xR1a)). Four of the haplogroups (P*(xR1a), BR(xDE, J, N3, P), R1a and N3) represented about 98% of the population sample. The analysis of population pairwise differences indicates that the Norwegian Y-chromosome distribution most closely resembles those observed in Iceland, Germany, the Netherlands and Denmark. Within Norway, geographical substructuring was observed between regions and counties. The substructuring reflects to some extent the European Y-chromosome gradients, with higher frequency of P*(xR1a) in the south-west and of R1a in the east. Heterogeneity in major founder groups, geographical isolation, severe epidemics, historical trading links and population movements may have led to population stratification and have most probably contributed to the observed regional differences in distribution of haplotypes within two of the major haplogroups.

Link

Y-haplogroups of some European population

A new paper in the Forensic Science International gives some interesting results

• Detection of 1 haplogroup A* and 2 BCD chromosomes in Germany (3.2% non-Caucasoid paternal admixture)
• Detection of 1 E*(xE3b) chromosome in Austria (0.8% non-Caucasoid paternal admixture)
• Detection of 1 R1a*(xR1a1) chromosome in Norway; usually R1a chromosomes also harbor the defining mutation for R1a1, but it appears that this is not always the case.

Forensic Science International (Article in Press, Corrected Proof)

A collaborative study of the EDNAP group regarding Y-chromosome binary polymorphism analysis

María Brion et al.

Abstract

A collaborative study was carried out by the European DNA Profiling Group (EDNAP) in order to evaluate the performance of Y-chromosome binary polymorphism analysis in different European laboratories. Four blood samples were sent to the laboratories, to be analysed for 11 Y-chromosome single nucleotide polymorphisms (SNPs): SRY-1532, M40, M35, M213, M9, 92R7, M17, P25, M18, M153 and M167. All the labs were also asked to submit a population study including these markers.

All participating laboratories reported the same results, indicating the reproducibility and robustness of Y-chromosome SNP typing.

A total of 535 samples from six different European populations were also analysed. In Galicia (NW Spain) and Belgium, the most frequent haplogroup was R1b*(xR1b1,R1b3df). Haplogroup F*(xK) is one of the most frequent in Austria and Denmark, while the lowest frequency appear in Belgium.

Haplogroup frequencies found in this collaborative study were compared with previously published European Y-chromosome haplogroup data.

Link

IQ falling?

The Flynn effect refers to the increase in IQ in recent history in several populations around the world. Several explanations have been proposed for this effect, but a new study from Denmark, replicating a previous one from Norway indicates that the Flynn effect has ceased in the 1990s, and indeed IQ has slightly dropped in recent years to early '90s levels.

Personality and Individual Differences (Article in Press)

A long-term rise and recent decline in intelligence test performance: The Flynn Effect in reverse

Thomas W. Teasdale and David R. Owen

Abstract

In the 1980s reviewed evidence indicated that, through the preceding decades of the last century, population performance on intelligence tests had been rising substantially, typically about 3–5 IQ points per decade, in developed countries. The phenomenon, now termed the ‘Flynn Effect’, has been variously attributed to biological and/or to social and educational factors. Although there is some evidence to suggest a slowing of the effect through the 1990s, only little evidence, to our knowledge, has yet been presented to show an arrest or reversal of the trend. Substantially replicating a recent report from Norway, we here report intelligence test results from over 500,000 young Danish men, tested between 1959 and 2004, showing that performance peaked in the late 1990s, and has since declined moderately to pre-1991 levels. A contributing factor in this recent fall could be a simultaneous decline in proportions of students entering 3-year advanced-level school programs for 16–18 year olds.

Link

mtDNA of an early Danish sample

Sample assignments and nucleotide substitutions:



Am J Phys Anthropol. [Epub ahead of print]

mtDNA analysis of human remains from an early Danish Christian cemetery.

Rudbeck L et al.

One of Denmark's earliest Christian cemeteries is Kongemarken, dating to around AD 1000-1250. A feature of early Scandinavian Christian cemeteries is sex segregation, with females buried on the northern sides and males on the southern sides. However, such separation was never complete; in the few early Christian cemeteries excavated in Scandinavia, there were always a few males placed on the north side, and some females on the south side. At Kongemarken, several males with juxtaposed females were found on the north side of the cemetery. Thus, to evaluate possible kinship relationships, and more general questions of population affinity, we analyzed mitochondrial DNA extracted from nine individuals excavated in two different areas within the cemetery: one male and four females from Area 1, and one male and three females from Area 2. Using stringent laboratory protocols, each individual was unequivocally assigned to a mitochondrial haplogroup. A surprising amount of haplogroup diversity was observed (Area 1: 1 U7 (male), 1 H, 1 I, 1 J, and 1 T2; Area 2: 2 H, 1 I, and 1 T, with one H being male); even the three subjects of haplogroup H were of different subtypes. This indicates that no subjects within each area were maternally related. The observed haplogroup, U7, while common in India and in western Siberian tribes, was not previously observed among present-day ethnic Scandinavians, and haplogroup I is rare (2%) in Scandinavia. These observations suggest that the individuals living in the Roskilde region 1,000 years ago were not all members of a tightly knit local population and comprised individuals with genetic links with populations that were from much farther away.

Link