Genes mirror geography within Europe
Recent studies suggest that by combining high-throughput genotyping technologies with dense geographic samples one can shed light on unanswered questions regarding human population structure
The investigation:
We surveyed genetic variation in a sample of 3,192 European individuals… genotyped at 500,568 loci… When available, we used the country of origin of each individual’s grandparents to determine the geographic location that best represents each individual’s ancestry, otherwise we used the self-reported country of birth… we focus our analyses on genotype data from 197,146 loci in 1,387 individuals for whom we have high confidence of individual origins.
The work gives some very strong results:
Individuals from the same geographic region cluster together and major populations are distinguishable. Geographically adjacent populations typically abut each other, and recognizable geographical features of Europe such as the Iberian peninsula, the Italian peninsula, southeastern Europe, Cyprus and Turkey are apparent. The data reveal structure even among French-, German- and Italian-speaking groups within Switzerland, and between Ireland and the United Kingdom.
Figure 1 | Population structure within Europe;
A statistical summary of genetic data from 1,387 Europeans based on principal component axis one (PC1) and axis two (PC2). Small coloured labels represent individuals and large coloured points represent median PC1 and PC2 values for each country. The inset map provides a key to the labels. The PC axes are rotated to emphasize the similarity to the geographic map of Europe.
AL, Albania; AT, Austria; BA, Bosnia-Herzegovina; BE, Belgium; BG, Bulgaria; CH, Switzerland; CY, Cyprus; CZ, Czech Republic; DE, Germany; DK, Denmark; ES, Spain; FI, Finland; FR, France; GB, United Kingdom; GR, Greece; HR, Croatia; HU, Hungary; IE, Ireland; IT, Italy; KS, Kosovo; LV, Latvia; MK, Macedonia; NO, Norway; NL, Netherlands; PL, Poland; PT, Portugal; RO, Romania; RS, Serbia and Montenegro; RU, Russia, Sct, Scotland; SE, Sweden; SI, Slovenia; SK, Slovakia; TR, Turkey; UA, Ukraine; YG, Yugoslavia.
Some findings according to the figure;
Some unexpected! findings;
Sources:
http://www.nature.com/nature/journal/vaop/ncurrent/abs/nature07331.html
http://www.eeb.ucla.edu/Faculty/Novembre/Novembreetal2008Nature.pdf
Recent studies suggest that by combining high-throughput genotyping technologies with dense geographic samples one can shed light on unanswered questions regarding human population structure
The investigation:
We surveyed genetic variation in a sample of 3,192 European individuals… genotyped at 500,568 loci… When available, we used the country of origin of each individual’s grandparents to determine the geographic location that best represents each individual’s ancestry, otherwise we used the self-reported country of birth… we focus our analyses on genotype data from 197,146 loci in 1,387 individuals for whom we have high confidence of individual origins.
The work gives some very strong results:
Individuals from the same geographic region cluster together and major populations are distinguishable. Geographically adjacent populations typically abut each other, and recognizable geographical features of Europe such as the Iberian peninsula, the Italian peninsula, southeastern Europe, Cyprus and Turkey are apparent. The data reveal structure even among French-, German- and Italian-speaking groups within Switzerland, and between Ireland and the United Kingdom.
Figure 1 | Population structure within Europe;
A statistical summary of genetic data from 1,387 Europeans based on principal component axis one (PC1) and axis two (PC2). Small coloured labels represent individuals and large coloured points represent median PC1 and PC2 values for each country. The inset map provides a key to the labels. The PC axes are rotated to emphasize the similarity to the geographic map of Europe.
AL, Albania; AT, Austria; BA, Bosnia-Herzegovina; BE, Belgium; BG, Bulgaria; CH, Switzerland; CY, Cyprus; CZ, Czech Republic; DE, Germany; DK, Denmark; ES, Spain; FI, Finland; FR, France; GB, United Kingdom; GR, Greece; HR, Croatia; HU, Hungary; IE, Ireland; IT, Italy; KS, Kosovo; LV, Latvia; MK, Macedonia; NO, Norway; NL, Netherlands; PL, Poland; PT, Portugal; RO, Romania; RS, Serbia and Montenegro; RU, Russia, Sct, Scotland; SE, Sweden; SI, Slovenia; SK, Slovakia; TR, Turkey; UA, Ukraine; YG, Yugoslavia.
Some findings according to the figure;
- While eastern countries shows relatively divers genes, western ones are relatively more homogeneous.
- The most genetically divers countries in Europe are; Italy, Greece, Yugoslavia and Turkey in order.
- The most genetically homogeneous countries in Europe are; Portugal-Spain, Ireland, Great Britain, Switzerland in order
- Northern Italians shows genetically relationship with Swiss, Spanish and some French in order. Southern Italians(Sicily, Sardinia, Tuscany) are genetically more closer to Greeks, Turks, Cypriots and Albanians. Some southern Italians are even more genetically related with Greeks and Turks than their northern countrymen.
- Greeks shows genetically relationship with southern Italians, Albanians, Turks, Yugoslavians, Macedonians, Kosovo, Cypriots in order.
- While Aegean Turks shows genetically relationship with Greeks, Southern Italians, Albanians and Yugoslavians in order, Northern(Blacksea) Turks are genetically more close to Kosovo, Yugoslavians, Greeks, Albanians and Macedonians in order.
- Macedonians are genetically close to Yugoslavians, Romanians, Bulgarians, Albanians and Kosovo in order. On the other hand, Macedonian`s genetic closeness to the Croatians are about same as their closeness to the northern Turks and much lesser then Romanians or Bulgarians.
- Bosnians, Serbians, Croatians, Slovenians creates a genetically related group within each other.
- Slovenians and Croatians are genetically more related with Hungarians, rather than Macedonians.
Some unexpected! findings;
- Greeks of Greece shows more closer relationship to Albanians, Southern Italians and Turks, rather than Greek Cypriots!!!
- Southern Italians and southern(Mediterranean) Turks are more closely related to Greek Cypriots than Greeks of Greece!!!
Sources:
http://www.nature.com/nature/journal/vaop/ncurrent/abs/nature07331.html
http://www.eeb.ucla.edu/Faculty/Novembre/Novembreetal2008Nature.pdf
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