Geological Origins of Italy

December 11, 2014

Italy broke off of the French Alps 30 million years ago, emerged from the sea 5-10 million years ago when it collided with the Adriatic Plate, and might end up joining the Balkans in 50-70 million years.

"Italy's Mystery Mountains". PBS International, 2014.

Italian Food Voted Best in Two Surveys

November 17, 2014

One in the U.S. and the other in the U.K.

A new survey commissioned by Intrepid Travel has found that Italian is the favorite foreign cuisine for most Americans, with one in five (21%) saying it's their top choice.

The poll was conducted for the small group adventure travel specialist by YouGov and queried Americans about their food preferences and eating habits while traveling. The survey found Italian food is the most popular cuisine among 18-34-year-olds (21%), and 35-54-year-olds (21%), while the 55+ age group is more patriotic in their choice of meal and most likely to favor American cuisine (28%).

"Italian Cuisine Voted Americans' Favorite Foreign Food". Marketwired, Feb 08, 2012.

British people think Italian food is the best in Europe, which reflects the popularity of pizza and pasta as well as famous Italian gourmet products, according to latest Holiday Hypermarket's poll. British food was second-most popular, followed by French and Spanish cuisines.


The online poll of 2,068 people in the UK asked the question: "Which European country do you think has the best national cuisine?" Italy was the most popular with 30 per cent, followed by the UK with 22 per cent, France with 12 per cent, Spain with six per cent and Greece with three per cent.

Age also played a big role in people's preferences: respondents over 55 are more likely to think British food is the best (26 per cent of those 55+, vs. 14 per cent of those 18-34), while younger respondents prefer easy Italian food (41 per cent of those 18-34 vs. 22 per cent of those 55+). While both men and women prefer Italian food over British overall, more men chose hardy British food than women (25 per cent vs. 19 per cent), while Italian food is more popular with women than men (33 per cent vs. 27 per cent).

"Brit poll: Italian cuisine the best in Europe". eTurboNews, May 10, 2012.

Against Lynn's Doctrine

October 1, 2014

Here's another refutation of Richard Lynn's flawed study on Italian IQ:

Lynn's study uses regional differences in the performance of Italian secondary school children on Organisation for Economic Co-operation and Development tests of educational achievement to assess regional IQ differences. However, data on Italian regional differences in educational achievement obtained in a much larger INVALSI study of 2,089,829 Italian schoolchildren provide unequivocal evidence that Lynn's educational achievement measure is not a valid index of IQ differences. More generally, the lengthy literature review in Lynn's article reveals uncritical acceptance of reported correlations between any putative index of IQ and socio-economic variables. Any measure of cognitive performance that is correlated with IQ is considered a measure of IQ, even if there is only a weak correlation. All correlations between such measures and socio-economic or public health variables are viewed as evidence of direct causal relationships. In all cases, causality is assumed to be in the direction that supports Lynn's doctrine when it would be equally valid to argue that socio-economic and public health differences cause differences in the performance of IQ tests. In addition to these fundamental logical and statistical errors the present report records numerous other data processing, methodological, and conceptual errors.

Robinson et al. "The case against Lynn's doctrine that population IQ determines levels of socio-economic development and public health status". J Pub Ment Health, 2011.

Overestimated Admixture in Brisighelli (2012)

September 8, 2014

This study tries to quantify individual ancestry in Italians by using a small panel of autosomal markers that are known to produce errors and overestimate admixture compared with using the full SNP data set, and as a result it comes up with estimates of Sub-Saharan African admixture in Italy and elsewhere in Europe that are much higher than in any other study:

A panel of 52 AIMs was genotyped in 435 Italian individuals in order to estimate the proportion of ancestry from a three-way differentiation: sub-Saharan Africa, Europe and Asia. Structure analyses allowed us to infer membership proportions in population samples, and these proportions can be graphically displayed, as in Figure 2. This analysis indicated that Italians have a basal proportion of sub-Saharan ancestry that is higher (9.2%, on average) than other central or northern European populations (1.5%, on average). The amount of African ancestry in Italians is however more comparable to (but slightly higher than) the average in other Mediterranean countries (7.1%).

The authors go on to say that Sub-Saharan African admixture in Italy is also evident in uniparental markers, but they should've been suspicious of their high AIM-based estimate when they found only 1.2% mtDNA haplogroup L and no A, B or E(xE3b) Y-DNA, which leads to an admixture estimate (0.6%) that's 15 times lower.

They also should've been puzzled by other bizarre results in their structure analysis, like African admixture appearing higher in Northern and Central Italy than in Southern Italy, with an equally high amount in Britain and Japan, and a very high Asian component in Central and Southern Italians that other Europeans don't have:

52 AIMs

Indeed, when we look at many of the same and similar populations tested using 291,184 SNPs in Lazaridis et al. (2014), we can see that the pattern is totally different and fits much better with the uniparental data and known reality. Italians only have a drop (<1%) of African admixture, which is highest in the south, while the British and Japanese don't have any at all, and Asian admixture is expectedly higher in Northern and Eastern Europe than it is in Southern Europe:

291,184 SNPs

These two very different results highlight the importance of using all genome-wide data when estimating individual ancestry and admixture proportions.

Brisighelli et al. "Uniparental Markers of Contemporary Italian Population Reveals Details on Its Pre-Roman Heritage". PLoS One, 2012.

Mediterranean Sea as Genetic Barrier

June 16, 2014

This new study confirms that the Mediterranean Sea has acted as a strong barrier to gene flow through geographic isolation following initial settlements. Samples from (Northern) Italy, Tuscany, Sicily and Sardinia are closest to other Southern Europeans from Iberia, the Balkans and Greece, who are in turn closest to the Neolithic migrants that spread farming throughout Europe, represented here by the Cappadocian sample from Anatolia. But there hasn't been any significant admixture from the Middle East or North Africa into Southern Europe since then.

Genes Mirror Geography Across the Mediterranean Basin

We first used principal components analysis (PCA) to visualize the genotypic distances between studied populations. Populations on the southern and northern coasts of the Mediterranean appear to be separated by the geographic barrier of the Mediterranean Sea. The role of the Mediterranean Sea as a barrier for gene flow among populations was also supported by our analysis using the BARRIER software, which implements Monmonier's maximum difference algorithm. In accordance with this finding...the PCA distribution of the populations closely resembles the geographic map of the countries circling the Mediterranean Sea. On this PCA "map" of populations, the east coast of the Mediterranean Sea is appropriately occupied by the Palestinians and the Lebanese Druze. Yemenites and Bedouins branch out from the Mediterranean populations and are closer to the populations of the Near East.


Seljuk Turks settled in Anatolia in the 12th century AD; however, the Anatolian Cappadocians we included in this study belong to the population that have kept the religion and the language of the pre-Seljuk Cappadocians and, therefore, most likely carry the genetic makeup of the ancient Anatolians. The only important gene flows from Near East to Europe must have occurred in prehistoric times and, as genetic evidence suggests, the most prominent migrations should have occurred during the Neolithic.


Although the Southeastern Mediterranean islands seem to have acted as a bridge from Anatolia to Southern Europe, the relatively small degree of gene flow between the African and the European coasts shows that the Mediterranean Sea also had a barrier function as also suggested with studies of mtDNA polymorphisms. Thus, the Mediterranean seems to have facilitated the migrations of Neolithic farmers along its Southern European coast but it mostly acted as an isolating factor between its European and African coasts.

Paschou et al. "Maritime route of colonization of Europe". PNAS, 2014.

Italian Ancestry of Ashkenazi Jews

March 8, 2014

Genetic similarities between Italians and Ashkenazi Jews are due to the fact that about half of Jews' ancestry is European, a lot of which came from Italy when diaspora males migrated to Rome and found wives among local women who then converted to Judaism. The same process happened again to a lesser degree in other parts of Europe as Jews migrated further north, west and then east, but according to genome-wide autosomal DNA, their highest European admixture is Italian.

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

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

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

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

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

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

Admixture between previously diverged populations yields patterns of genetic variation that can aid in understanding migrations and natural selection. An understanding of individual admixture (IA) is also important when conducting association studies in admixed populations. However, genetic drift, in combination with shallow allele frequency differences between ancestral populations, can make admixture estimation by the usual methods challenging. We have, therefore, developed a simple but robust method for ancestry estimation using a linear model to estimate allele frequencies in the admixed individual or sample as a function of ancestral allele frequencies. The model works well because it allows for random fluctuation in the observed allele frequencies from the expected frequencies based on the admixture estimation. We present results involving 3,366 Ashkenazi Jews (AJ) who are part of the Kaiser Permanente Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort and genotyped at 674,000 SNPs, and compare them to the results of identical analyses for 2,768 GERA African Americans (AA). For the analysis of the AJ, we included surrogate Middle Eastern, Italian, French, Russian, and Caucasus subgroups to represent the ancestral populations. For the African Americans, we used surrogate Africans and Northern Europeans as ancestors. For the AJ, we estimated mean ancestral proportions of 0.380, 0.305, 0.113, 0.041 and 0.148 for Middle Eastern, Italian, French, Russian and Caucasus ancestry, respectively. For the African Americans, we obtained estimated means of 0.745 and 0.248 for African and European ancestry, respectively. We also noted considerably less variation in the individual admixture proportions for the AJ (s.d. = .02 to .05) compared to the AA (s.d.= .15), consistent with an older age of admixture for the former. From the linear model regression analysis on the entire population, we also obtain estimates of goodness of fit by r2. For the analysis of AJ, the r2 was 0.977; for the analysis of the AA, the r2 was 0.994, suggesting that genetic drift has played a more prominent role in determining the AJ allele frequencies. This was confirmed by examination of the distribution of differences for the observed versus predicted allele frequencies. As compared to the African Americans, the AJ differences were significantly larger, and presented some outliers which may have been the target of selection (e.g. in the HLA region on chromosome 6p).

Banda et al. "Admixture Estimation in a Founder Population". Am Soc Hum Genet, 2013.

Two major differences among the populations in this study were the high degree of European admixture (30%-60%) among the Ashkenazi, Sephardic, Italian, and Syrian Jews and the genetic proximity of these populations to each other compared to their proximity to Iranian and Iraqi Jews. This time of a split between Middle Eastern Iraqi and Iranian Jews and European/Syrian Jews, calculated by simulation and comparison of length distributions of IBD segments, is 100–150 generations, compatible with a historical divide that is reported to have occurred more than 2500 years ago. The Middle Eastern populations were formed by Jews in the Babylonian and Persian empires who are thought to have remained geographically continuous in those locales. In contrast, the other Jewish populations were formed more recently from Jews who migrated or were expelled from Palestine and from individuals who were converted to Judaism during Hellenic-Hasmonean times, when proselytism was a common Jewish practice. During Greco-Roman times, recorded mass conversions led to 6 million people practicing Judaism in Roman times or up to 10% of the population of the Roman Empire. Thus, the genetic proximity of these European/Syrian Jewish populations, including Ashkenazi Jews, to each other and to French, Northern Italian, and Sardinian populations favors the idea of non-Semitic Mediterranean ancestry in the formation of the European/Syrian Jewish groups and is incompatible with theories that Ashkenazi Jews are for the most part the direct lineal descendants of converted Khazars or Slavs. The genetic proximity of Ashkenazi Jews to southern European populations has been observed in several other recent studies.

Atzmon et al. "Abraham's Children in the Genome Era: Major Jewish Diaspora Populations Comprise Distinct Genetic Clusters with Shared Middle Eastern Ancestry". Am J Hum Genet, 2010.